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AS 2467—2008

Australian Standard®

Maintenance of electrical switchgear

AS 2467—2008
 This Australian Standard® was prepared by Committee EL-007, Power Switchgear. It was
approved on behalf of the Council of Standards Australia on 8 November 2007.
This Standard was published on 5 February 2008.

The following are represented on Committee EL-007:

• Australian British Chamber of Commerce

• Australian Electrical and Electronic Manufacturers Association
• Australian Railway Association
• Energy Networks Association
• Engineers Australia
• Testing interests

Standards Australia wishes to acknowledge the participation of the expert individuals that
contributed to the development of this Standard through their representation on the
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Committee.

Keeping Standards up-to-date

Australian Standards® are living documents that reflect progress in science, technology and
systems. To maintain their currency, all Standards are periodically reviewed, and new editions
are published. Between editions, amendments may be issued.

Standards may also be withdrawn. It is important that readers assure themselves they are
using a current Standard, which should include any amendments that may have been
published since the Standard was published.

Detailed information about Australian Standards, drafts, amendments and new projects can
be found by visiting www.standards.org.au

Standards Australia welcomes suggestions for improvements, and encourages readers to

notify us immediately of any apparent inaccuracies or ambiguities. Contact us via email at
mail@standards.org.au, or write to Standards Australia, GPO Box 476, Sydney, NSW 2001.
 AS 2467—2008

Australian Standard®

Maintenance of electrical switchgear

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Originated as AS CC9—1965.
Revised and redesignated as AS 2467—1981.
Second edition 2008.

COPYRIGHT
© Standards Australia
All rights are reserved. No part of this work may be reproduced or copied in any form or by
any means, electronic or mechanical, including photocopying, without the written
permission of the publisher.
Published by Standards Australia GPO Box 476, Sydney, NSW 2001, Australia
ISBN 0 7337 8527 1
 AS 2467—2008 2

PREFACE
This Standard was reviewed by the Standards Australia Committee EL-007, Power
Switchgear, to supersede AS 2467—1981.
This Standard is republished from AS 2467—1981, without technical alterations.
Referenced Standards have been updated.
The objective of this Standard is to provide basic recommendations for the safety of
personnel in proximity to or engaged in maintenance of electrical switchgear and includes
detailed recommendations for particular types of switchgear.
This Standard sets out a standard of good practice and generally takes the form of
recommendations. Compliance with it does not confer immunity from relevant statutory and
legal requirements (see Clause 1.3).
The terms ‘normative’ and ‘informative’ are used to define the application of the Appendix
to which they apply. A normative Appendix is an integral part of a standard, whereas an
informative Appendix is only for information and guidance.
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 3 AS 2467—2008

CONTENTS

Page

SECTION 1 SCOPE AND GENERAL

1.1 SCOPE ........................................................................................................................ 6
1.2 RATIONALE .............................................................................................................. 6
1.3 OBJECT ...................................................................................................................... 6
1.4 APPLICATION ........................................................................................................... 7
1.5 STATUTORY AND LEGAL REQUIREMENTS ....................................................... 7
1.6 DEFINITIONS ............................................................................................................ 7

SECTION 2 SAFETY OF PERSONNEL

2.1 GENERAL ................................................................................................................ 10
2.2 RESPONSIBILITY ................................................................................................... 10
2.3 FIRST AID ................................................................................................................ 10
2.4 ACCESS.................................................................................................................... 10
2.5 SAFETY RULES....................................................................................................... 10

SECTION 3 SAFETY PROVISIONS FOR MAINTENANCE OPERATIONS

3.1 GENERAL ................................................................................................................ 12
3.2 AVOIDANCE OF MOISTURE AND DUST ............................................................ 12
3.3 CONTAINMENT OF FAULTS ................................................................................ 12
3.4 FIRE EXTINGUISHING EQUIPMENT ................................................................... 12
3.5 EMERGENCY EXITS .............................................................................................. 13
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3.6 LIGHTING ................................................................................................................ 13

3.7 ACCESS.................................................................................................................... 13
3.8 EARTHING EQUIPMENT ....................................................................................... 13
3.9 EARTH MATS.......................................................................................................... 14
3.10 INSULATING MATS, STANDS, SCREENS AND OTHER SIMILAR
EQUIPMENT ............................................................................................................ 14
3.11 VERIFICATION THAT CONDUCTORS ARE NOT ALIVE .................................. 14
3.12 PROTECTION AGAINST INDUCTION .................................................................. 14
3.13 DETECTION OF HAZARDOUS GASES................................................................. 14
3.14 DANGER FROM STORED ENERGY...................................................................... 14
3.15 PORTABLE ELECTRIC TOOLS ............................................................................. 14
3.16 INSTRUCTIONS, NOTICES AND LABELS ........................................................... 14

SECTION 4 FREQUENCY OF MAINTENANCE OPERATIONS

4.1 GENERAL ................................................................................................................ 16
4.2 PLANNING THE FREQUENCY OF MAINTENANCE OPERATIONS.................. 16
4.3 INSULATING OIL.................................................................................................... 18
4.4 RECOMMENDED INTERVALS.............................................................................. 18

SECTION 5 MAINTENANCE OF SWITCHGEAR INTENDED TO OPERATE AT

VOLTAGES UP TO 1000 V a.c. AND 1200 V d.c.
5.1 PRE-MAINTENANCE REQUIREMENTS AND PRECAUTIONS.......................... 20
5.2 FREQUENCY OF MAINTENANCE........................................................................ 20
5.3 DIAGNOSTIC TESTING.......................................................................................... 20
5.4 ROUTINE MAINTENANCE .................................................................................... 21
5.5 POST-FAULT MAINTENANCE.............................................................................. 24
5.6 MAINTENANCE OF AUXILIARY EQUIPMENT .................................................. 24
5.7 SUMMARY OF MAINTENANCE OPERATIONS .................................................. 24
 AS 2467—2008 4

Page

SECTION 6 MAINTENANCE OF AIR-BREAK SWITCHGEAR INTENDED FOR

OPERATION AT VOLTAGES ABOVE 1000 V a.c. AND 1200 V d.c.
6.1 PRE-MAINTENANCE REQUIREMENTS AND PRECAUTIONS.......................... 26
6.2 FREQUENCY OF MAINTENANCE........................................................................ 27
6.3 DIAGNOSTIC TESTING.......................................................................................... 27
6.4 OPERATIONAL CHECK ......................................................................................... 27
6.5 ROUTINE MAINTENANCE .................................................................................... 27
6.6 POST-FAULT MAINTENANCE.............................................................................. 33
6.7 MAINTENANCE OF AUXILIARY EQUIPMENT .................................................. 33
6.8 HIGH-VOLTAGE FUSE CONNECTIONS AND ASSOCIATED LINKAGE.......... 33
6.9 SUMMARY OF MAINTENANCE OPERATIONS .................................................. 33

SECTION 7 MAINTENANCE OF OIL SWITCHGEAR

7.1 APPLICATION OF SECTION.................................................................................. 35
7.2 SPECIAL PRECAUTIONS FOR OIL SWITCHGEAR............................................. 35
7.3 ROUTINE MAINTENANCE .................................................................................... 35
7.4 POST-FAULT MAINTENANCE.............................................................................. 37
7.5 SUMMARY OF MAINTENANCE OPERATIONS .................................................. 38

SECTION 8 MAINTENANCE OF AIR-BLAST CIRCUIT-BREAKER SWITCHGEAR

8.1 APPLICATION OF SECTION.................................................................................. 40
8.2 PRE-MAINTENANCE REQUIREMENTS AND PRECAUTIONS.......................... 40
8.3 ROUTINE MAINTENANCE .................................................................................... 40
8.4 POST-FAULT MAINTENANCE.............................................................................. 44
8.5 SUMMARY OF MAINTENANCE OPERATIONS .................................................. 44
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SECTION 9 MAINTENANCE OF VACUUM CIRCUIT-BREAKER SWITCHGEAR

9.1 APPLICATION OF SECTION.................................................................................. 46
9.2 GENERAL ................................................................................................................ 46
9.3 FREQUENCY OF MAINTENANCE........................................................................ 46
9.4 ROUTINE MAINTENANCE .................................................................................... 46
9.5 POST-FAULT MAINTENANCE.............................................................................. 47
9.6 SUMMARY OF MAINTENANCE OPERATIONS .................................................. 47

SECTION 10 MAINTENANCE OF SULPHUR HEXAFLUORIDE CIRCUIT-BREAKER

SWITCHGEAR
10.1 APPLICATION OF SECTION.................................................................................. 49
10.2 SPECIAL CONSIDERATIONS ARISING FROM THE USE OF SULPHUR
HEXAFLUORIDE..................................................................................................... 49
10.3 PRE-MAINTENANCE REQUIREMENTS AND PRECAUTIONS.......................... 50
10.4 FREQUENCY OF MAINTENANCE........................................................................ 50
10.5 ROUTINE MAINTENANCE .................................................................................... 51
10.6 POST-FAULT MAINTENANCE.............................................................................. 55
10.7 SUMMARY OF MAINTENANCE OPERATIONS .................................................. 55

SECTION 11 DIAGNOSTIC TESTING

11.1 GENERAL ................................................................................................................ 57
11.2 DIAGNOSTIC TESTS FOR CORRECT OPERATION ............................................ 57
11.3 DIAGNOSTIC TESTS FOR CONTACTS AND CONNECTIONS........................... 58
11.4 DIAGNOSTIC TESTS FOR INSULATION ............................................................. 58
 5 AS 2467—2008

Page

SECTION 12 MAINTENANCE OF AUXILIARY ITEMS

12.1 EQUIPMENT FOR TRIPPING AND CLOSING CURRENT SUPPLY ................... 61
12.2 GENERAL PRECAUTIONS FOR BATTERY INSTALLATIONS .......................... 61
12.3 SECONDARY CELL BATTERIES .......................................................................... 61
12.4 PRIMARY CELL BATTERIES ................................................................................ 62
12.5 COMPRESSED AIR PLANT .................................................................................... 63
12.6 CURRENT TRANSFORMERS................................................................................. 63
12.7 VOLTAGE TRANSFORMERS ................................................................................ 63
12.8 EQUIPMENT EARTHING CONNECTIONS ........................................................... 64
12.9 OTHER AUXILIARY DEVICES.............................................................................. 64
12.10 REPLACEMENT PARTS ......................................................................................... 64

SECTION 13 MAINTENANCE OF PROTECTIVE APPARATUS

13.1 GENERAL ................................................................................................................ 65
13.2 REMOVAL OF DUST .............................................................................................. 65
13.3 CONNECTIONS ....................................................................................................... 65
13.4 ROUTINE TRIPPING TESTS................................................................................... 65
13.5 PROTECTIVE APPARATUS INCORPORATING SEMICONDUCTORS .............. 65
13.6 INJECTION TESTS .................................................................................................. 65
13.7 RELAYS ................................................................................................................... 65

SECTION 14 MAINTENANCE AND TESTING OF INSULATION

14.1 GENERAL ................................................................................................................ 66
14.2 ROUTINE TESTING AND INSPECTION ............................................................... 66
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14.3 ELECTROSTATICALLY GRADED (CONDENSER) BUSHINGS......................... 67

14.4 OIL BARRIER BUSHINGS...................................................................................... 67
14.5 LAMINATED INSULATION ................................................................................... 67
14.6 PORCELAIN INSULATION .................................................................................... 67
14.7 APPLIED VOLTAGES FOR INSULATION RESISTANCE TESTS ....................... 68
14.8 POWER FREQUENCY WITHSTAND TESTS AFTER MAINTENANCE.............. 68

APPENDICES
A EXAMPLE OF ELECTRICAL SAFETY RULES..................................................... 69
B MAINTENANCE RECORD FORMS ....................................................................... 80
C FIRE PROTECTION EQUIPMENT.......................................................................... 84
D GRAPHICAL ILLUSTRATION OF SOME OF THE TERMS AND DEFINITIONS
GIVEN IN CLAUSE 1.4 ........................................................................................... 85
E APPROPRIATE ACTS AND REGULATIONS ........................................................ 86
F REFERENCED DOCUMENTS ................................................................................ 89
 AS 2467—2008 6

STANDARDS AUSTRALIA

Australian Standard
Maintenance of electrical switchgear

SECT ION 1 SCOPE AND GENERA L

1.1 SCOPE
This Standard sets out procedures and recommendations for the maintenance of electrical
switchgear. It is applicable to electrical switchgear having rated voltages not greater than
145 kV. At voltages above this level the design of equipment, system operations and
consequently maintenance requirements and practices may differ significantly from those at
voltages up to this level. However, the principles formulated in this Standard as good
practice, especially those regarding the safety of personnel, are for the most part applicable
at the higher voltages.
The Standard does not apply to the maintenance of electrical switchgear—
(a) of sealed construction intended only to be returned to the manufacturer for adjustment
and repair; or
(b) used in explosive atmospheres and in coal mines. Reference should be made to
appropriate Standards for the maintenance of electrical equipment used in explosive
atmospheres and in coal mines.
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1.2 RATIONALE
Electrical switchgear, by the nature of the service it renders, does not automatically call for
the maintenance attendance which is necessary to ensure its effective functioning at all
times. Its normally quiescent state does not generally draw attention to incipient faults or
deterioration or to the danger resulting from neglect.
It follows therefore that only an organized system of routine maintenance planned to
include all necessary details can ensure continued safe and satisfactory operation of an
electrical system with a minimum risk of breakdown and the consequent interruption of
supply.
NOTE: In this Standard, the words ‘examination’ and ‘inspection’ have a meaning strictly as
defined in Clauses 1.6.4 and 1.6.6 respectively.

1.3 OBJECT
The object of this Standard is to provide in a convenient form a record of those matters
which technical knowledge and experience have shown to be important in keeping electrical
switchgear, both indoor and outdoor, and its associated apparatus in an acceptable
condition. It also draws attention to the precautions which should be observed in order to
secure the safety of personnel while maintenance is in progress, and in this respect the
following matters are covered:
(a) Safety rules.
(b) Safety features of equipment.
(c) Measures to minimize hazards to plant and to ensure continuity of service.
(d) The use of electrical testing to detect insulation weakness or the deteriorating
condition of insulation.

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 7 AS 2467—2008

1.4 APPLICATION
The application of Sections 2 to 14 is as follows:
(a) Section 2 sets out general provisions and rules for the safety of personnel engaged in
the maintenance of switchgear, first aid and the responsibility of authorized persons.
(b) Section 3 sets out general design considerations for a switchgear installation, safe
practices for the use of equipment emergency exits, instruction and warning notices
and provision of facilities to minimize the risk of injury, damage to equipment and
fire.
(c) Section 4 deals with the determination of the frequency of maintenance operations for
items of switchgear, components and materials in relation to service duty and
conditions of use.
(d) Section 5 applies to the maintenance of switchgear, intended to be serviced, for
voltages up to 1000 V a.c. and 1200 V d.c.
(e) Section 6 applies to the maintenance of air-break switchgear for voltages above
1000 V a.c. and 1200 V d.c. A number of the recommendations in this Section are
applicable to other types of high-voltage switchgear and reference is made in
subsequent Sections to appropriate clauses of Section 6.
(f) Section 7 applies to the maintenance of oil switchgear.
(g) Section 8 applies to the maintenance of air-blast circuit-breaker switchgear and
compressed air handling equipment in installations of such switchgear.
(h) Section 9 applies to the maintenance of vacuum circuit-breaker switchgear.
(i) Section 10 applies to the maintenance of sulphur hexafluoride (SF 6) switchgear and
special safety measures necessary due to the properties of this gas.
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(j) Section 11 sets out diagnostic testing methods and procedures which are
recommended to prolong the intervals between dismantling of equipment for routine
maintenance.
(k) Section 12 applies to the maintenance of auxiliary equipment items such as batteries,
compressed air plant, transformers, earthing connections and oil handling plant.
(l) Section 13 applies to the maintenance of protective apparatus, fuses and relays.
(m) Section 14 deals with the testing and maintenance of electrical insulation.

1.5 STATUTORY AND LEGAL REQUIREMENTS

This Standard represents a standard of good practice and generally takes the form of
recommendations. Compliance with this Standard does not confer immunity from relevant
statutory or legal requirements.
Appendix E lists examples of the Acts and Regulations which apply in the various States.

1.6 DEFINITIONS
For the purpose of this Standard, the following definitions apply. Those marked with an
asterisk (*) are illustrated graphically in Appendix D.
1.6.1 Acceptable conditions*
The condition in which an item is able to perform its required function and/or meet the
relevant specification.

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 AS 2467—2008 8

1.6.2 Electrical station

A building, room(s) or designated space which houses the electrical equipment in an
installation.
NOTE: An electrical station may also be known as a substation, switchroom, etc.
1.6.3 Emergency action
Action which must be put in hand immediately to avoid serious consequence.
1.6.4 Examination
An inspection with the addition of partial dismantling as required, supplemented by means
such as measurements and non-destructive tests in order to arrive at a reliable conclusion as
to the condition of an item.
NOTE: An examination should be followed by an operational check.
1.6.5 Failure (breakdown)*
The termination of the ability of an item to perform its required function.
NOTE: Failure can be gradual, sudden, partial or complete.
1.6.6 Inspection
Maintenance action comprising a careful scrutiny of an item carried out without dismantling
and using all the senses as required to detect anything which causes the item to fail to meet
an acceptable condition.
NOTE: An inspection may be followed by an operational check.
1.6.7 Item
Any part of equipment including a composite which can be individually considered.
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1.6.8 Maintenance
A combination of any actions carried out to retain an item in, or restore it to, an acceptable
condition.
1.6.8.1 Non-routine maintenance
Unplanned maintenance which is not the result of a breakdown.
1.6.8.2 Preventive maintenance*
Maintenance carried out with the objective of preventing breakdown and which may include
routine or non-routine maintenance. (See also Appendix B.)
1.6.8.3 Post-fault maintenance
Maintenance necessary on switchgear after a specified number of fault clearance operations.
1.6.8.4 Repair or corrective maintenance*
Maintenance necessary to restore to an acceptable condition an item which has ceased to
meet an acceptable condition.
1.6.8.5 Routine maintenance
Maintenance organized and carried out in accordance with a predetermined policy or plan to
prevent breakdown or reduce the likelihood of an item failing to meet an acceptable
condition.
1.6.9 Operational check
An action carried out to determine whether an item functions correctly.
1.6.10 Test
A measurement carried out to determine the condition of an item.

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 9 AS 2467—2008

1.6.10.1 Diagnostic testing

A technique involving the establishing of comparative data for monitoring and checking the
condition of equipment.
1.6.11 Overhaul
Maintenance of an item including examination and replacement or rebuilding as required.
Overhaul can be further categorized as follows:
(a) Minor overhaul or servicing—an overhaul which is limited to lubrication and/or
replacement of consumables.
(b) Major overhaul.
An overhaul which includes major dismantling and/or replacement of items to complete the
maintenance.
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 AS 2467—2008 10

SE C T I ON 2 S A FE T Y O F PE RSO N N E L

2.1 GENERAL
In view of the potential dangers associated with electrical equipment, appropriate measures
shall be taken to safeguard personnel.
NOTE: Attention is drawn to the statutory requirements applicable to persons engaged in the
maintenance of electrical switchgear and associated equipment.

2.2 RESPONSIBILITY
2.2.1 Statutory requirements
It is the responsibility of engineers and other supervisory personnel engaged in electrical
work or operations to become acquainted with the statutory requirements applicable to their
industry.
2.2.2 Authorized person
Any person to whom responsibility for electrical safety is delegated should be designated as
an authorized person.

2.3 FIRST AID

A notice giving instructions for the treatment of persons suffering from electric shock
should be affixed in a prominent position in all locations where maintenance is carried out.
Furthermore first aid equipment should be available for the treatment of personnel.
The address and telephone number of the nearest ambulance, first aid centre or hospital
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should be prominently displayed on the premises.

It is strongly recommended that all electrical maintenance personnel be trained in both the
rescue of people and the application of resuscitation techniques.
NOTE: Consideration should be given to the training of staff in the rescue of people from live
high-voltage areas.

2.4 ACCESS
Access to electrical stations should be restricted and, where necessary, suitable barriers
should be installed to prevent access to enclosures, chambers, cubicles or cells containing
exposed live conductors.

2.5 SAFETY RULES

2.5.1 General
Safety in the control, operation and maintenance of switchgear is best achieved by the
observance of a simple code of safety rules. Electricity supply authorities and other
organizations have produced their own safety rules which specify procedures for operating
and for initiating and carrying out work on particular items of equipment or apparatus. It is
recommended that in all premises the occupier should draft a set of safety rules appropriate
to his type of electrical installation, covering the operation of and work to be carried out on
the equipment on his premises.
2.5.2 Anticipating dangers
The policy to be followed when drafting safety rules should attempt to foresee any danger
that can or may develop and to institute procedures and methods which will inhibit danger
as far as practicable.

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 11 AS 2467—2008

2.5.3 Familiarity with rules

The best rules are of no avail unless all persons operating or working on the equipment
covered by the rules are thoroughly conversant with them and with the relevant statutory
requirements and comply strictly with them.
2.5.4 Supply authority rules
Where a consumer carries out switching or maintenance work on switchgear controlled by a
supply authority, the consumer shall ascertain and comply with the supply authority’s safety
rules.
2.5.5 High-voltage equipment
Safety rules should be so drafted as to prevent any person being exposed to danger from
live conductors. A good aid, particularly for high-voltage equipment, is the use of an access
permit procedure similar to that described in Appendix A, Paragraphs 25 and 26. Relaxation
of these principles should be permitted only where the design of apparatus precludes strict
compliance and then only with special precautions to avoid danger.
NOTE: An example of comprehensive safety rules is given in Appendix A. These are the
Electrical Safety Rules issued by the Energy Authority of New South Wales and it is
recommended that the person on whom responsibility for electrical safety rests should incorporate
or adapt these rules, as appropriate, in drafting a set of safety rules to cover his particular
installation.
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 AS 2467—2008 12

SEC T I ON 3 S A FE T Y P RO V IS I O N S FO R
MA I N T E N A N CE O PE RA T I O N S

3.1 GENERAL
The performance and safe operation of electrical equipment is dependent on the initial
design of the electrical station and the layout, installation and environment of the
equipment. It is therefore important that these aspects be considered at the design and
installation stages.
Clauses 3.2 to 3.16 list the operation and maintenance procedures which should be carried
out to maintain the safety provisions.

3.2 AVOIDANCE OF MOISTURE AND DUST

The entry of moisture and dust into electrical equipment and its associated control
equipment can cause malfunction. During all maintenance operations an inspection should
be carried out for evidence of dampness or condensation in all electrical equipment and if
this is observed, remedial action should be taken, e.g. by the improvement of ventilation,
the provision of heaters or other suitable means.
Where practicable, the entry of dust should be prevented.

3.3 CONTAINMENT OF FAULTS

The physical separation of switchboards into sections and the provision of fire-resistant
barriers can assist in the more rapid restoration of supplies after a fault, and the
containment and limitation of possible damage. The inspection of an electrical station
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should include inspection of any seals provided on cable access points and any other
provision made to prevent the passage of flame, smoke, gas or liquid or of any fire-resisting
barriers.
Where steps have been taken in an electrical station to prevent the spreading of an oil
spillage, such as the provision of dwarf walls, raised door thresholds or catchment areas,
these should be inspected to see that they are effective, and that any gravel or pebble bed
used is in a porous condition.

3.4 FIRE EXTINGUISHING EQUIPMENT

3.4.1 Availability of equipment and training of personnel
All personnel carrying out maintenance on switchgear where there is a fire risk should have
available some means of fighting fire, either by appliances permanently in the premises or
by temporary appliances provided during the period of the work, and should be trained in
the use of such appliances.
3.4.2 Suitability for intended purpose
The type of fire extinguishing equipment provided for use on electrical equipment should
be compatible with the electrical equipment and not dangerous to use in the situation, e.g.
water fire extinguishers are not generally suitable for use on oil fires and can also cause
further damage to electrical equipment and endanger personnel.
3.4.3 Inspection and labelling
Fire extinguishing equipment should be inspected regularly to the manufacturer’s
instructions. The equipment should be labelled with the type of extinguishing medium and
with instructions for use.

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 13 AS 2467—2008

3.4.4 Renewal or recharge after use

Fire extinguishing equipment should be renewed or recharged immediately after use.
3.4.5 Automatic fire extinguishing installations
Where automatic fire extinguishing installations are provided, this provision should be
prominently indicated by a notice outside the electrical station, which should also show the
procedure to cancel the automatic feature. The procedures to safeguard personnel against
danger when entering chambers fitted with automatic fire extinguishing equipment, or when
in chambers in which fire extinguishing equipment has operated, are given in Appendix C.

3.5 EMERGENCY EXITS

All emergency exits should be clearly labelled inside and out and properly secured to
prevent the entrance of an unauthorized person from outside whilst at all times allowing
free escape from inside. All emergency exits should be inspected during inspection of the
electrical station and shall be kept clear.

3.6 LIGHTING
Adequate lighting, either fixed or portable or a combination of both, shall be provided to
ensure safe access and working conditions for all personnel in electrical stations.

3.7 ACCESS
Electrical stations should be designed to prevent access and interference by unauthorized
persons. Inspections should be made to see that this security is maintained. Doors and other
means of entry should be kept secure by locking or other suitable methods.
To avoid danger, working space and access ways provided to apparatus and equipment
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which is to be worked upon or operated should be properly maintained and kept free of
obstructions. (See AS 2067 for information on safety clearances.).
Provisions for access to allow work on equipment should be as recommended by the
manufacturer. Work platforms should not be erected around the equipment until after the
equipment has been isolated, earthed and made inoperative. The leaning of ladders against
porcelain insulation is not generally recommended.

3.8 EARTHING EQUIPMENT

3.8.1 Availability of earthing equipment
Earthing (see Appendix A) is an essential safeguard for personnel carrying out work on
high-voltage equipment and suitable earthing equipment should be available; this may
consist of special earthing contacts provided in the switchgear, equipment for attachment to
the switchgear, or portable equipment. (See also Appendix A, rule 23.)
3.8.2 Suitability of earthing equipment
Earthing equipment should be of an approved type and have adequate current-carrying
capacity to suit the fault level of the installation.
3.8.3 Inspection
Before each use it is good practice to inspect earthing equipment, particularly connections
and insulation. Earthing sticks should be subjected to high-voltage testing at regular
intervals.
3.8.4 Permanently stored earthing equipment
Earthing equipment permanently stored in an installation should be kept in storage
particularly made for that purpose, and included in the inspection of the installation.

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 AS 2467—2008 14

3.9 EARTH MATS

The integrity of the connection between an earth mat and switchgear operating handle(s)
should be regularly inspected.

3.10 INSULATING MATS, STANDS, SCREENS AND OTHER SIMILAR

EQUIPMENT
Permanent and portable insulating mats, stands or screens should be inspected and
maintained in good condition. Insulated gloves of adequate capacity and of sound quality
(see AS 2225) should be available to personnel when required. Insulated gloves should be
tested at regular intervals.

3.11 VERIFICATION THAT CONDUCTORS ARE NOT ALIVE

Prior to the application of any earthing leads, equipment required to be earthed should be
proved dead. Any indicating device used for this purpose should be tested in the approved
manner both immediately before and immediately after use.

3.12 PROTECTION AGAINST INDUCTION

When work is being carried out in e.h.v. stations, special precautions may be necessary to
protect personnel against induction.

3.13 DETECTION OF HAZARDOUS GASES

Where ingress of hazardous gases into an area containing electrical installations may occur,
suitable indicators should be provided to indicate the presence of such gas.
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3.14 DANGER FROM STORED ENERGY

Special precautions should be taken to avoid hazards when work is to be carried out at
locations where stored energy is available due to compressed air, other gases or mechanical
means such as spring latched mechanisms.

3.15 PORTABLE ELECTRIC TOOLS

Where handlamps and portable tools operating from voltages not exceeding 250 V are used,
they shall comply with AS/NZS 60598.2.8 and AS/NZS 3160, as appropriate, and should be
of double insulated construction.
It is further recommended that, where practicable, hand lamps and portable electric tools be
operated on voltages not exceeding 32 V.
The use of trailing cables should be minimized and any such cable should be of adequate
construction and properly protected, e.g. by earth-leakage circuit-breakers preferably of the
current-operated type. Cable connectors should be of suitable design for the environment in
which they are operating.
All portable equipment should be regularly inspected and tested and have a label showing
the due date for the next test attached. Where practicable, the equipment should be
inspected before each use.

3.16 INSTRUCTIONS, NOTICES AND LABELS

3.16.1 Availability and display
Adequate instructions, diagrams and data shall be available to persons operating, in charge
of work or working in electrical stations, to ensure proper and safe control of equipment
and isolation for working.

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 15 AS 2467—2008

Notices and labels required by statutory regulations shall be displayed together with any
other notices or labels necessary for identification of equipment and its function.
3.16.2 Removal and replacement of identification labels
Where more than one unit of switchgear is out of service in the one switchroom, particular
care should be taken to avoid inadvertent removal, replacement or exchange of labels which
have previously been attached to the switchgear units removed from service.
3.16.3 Caution and danger plates
Adequate quantities of caution and danger plates should be kept in the electrical station for
immediate use with the number of safety locks (see Appendix A, rule 7) required for the
operation of the equipment. (See also AS 1319.).
3.16.4 Emergency exits
Emergency exits should be clearly labelled as such inside and outside. The labels should be
clearly visible even under adverse conditions.
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 AS 2467—2008 16

SE C T I ON 4 F R E Q U E N CY O F M A I N T E N A N CE
OPERAT I ONS

4.1 GENERAL
Because of the widely varying conditions of operation of individual switchgear
installations, it is not always possible to lay down a general recommendation for the
intervals between maintenance operations. These intervals may vary greatly depending
upon the design of the switchgear, the duty that it is called on to perform, and the
environment in which it is situated.

4.2 PLANNING THE FREQUENCY OF MAINTENANCE OPERATIONS

4.2.1 Manufacturer’s instructions
When the frequencies of maintenance operations for particular items of plant are being
planned, the manufacturer’s instructions should be consulted.
4.2.2 Newly commissioned equipment
4.2.2.1 Examination prior to commissioning and within 12 months of commissioning
Switchgear of all types irrespective of the class of duty should be examined prior to
commissioning and inspected or examined within 12 months of commissioning. The latter
examination should prudently be carried out before the end of the manufacturer’s warranty
period.
Particular attention should be paid to the tightness of any fixings and fastenings (especially
those associated with moving parts and conductor joints), internal cleanliness, condition of
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insulation, recommended clearance, and setting and efficacy of the close/open operations as
a whole.
These inspections or examinations can give guidance on the intervals that might be allowed
to elapse between future inspections, examination and overhaul operations with reference to
particular service conditions. When estimating these intervals it would be necessary to
consider the condition of the equipment at the time of the examination with regard to the
following:
(a) Contamination of external insulation.
(b) Condition of internal insulation including oil where appropriate.
(c) Condition of contacts, interrupting devices and connections.
(d) Condition of operating mechanisms and their lubrication.
(e) Condition of weather seals and gaskets.
(f) Condition of protective finishes and signs of corrosion.
4.2.2.2 Contacts, arc-control devices and internal insulation
The condition of contacts and arc-control devices will normally depend on the number of
operations performed by a circuit-breaker and whether such operations are load or fault-
current breaking. It will assist if a log of switching operations is kept.
Similar considerations may apply to the condition of the internal insulation, but in this case
the influence of moisture ingress may be relevant, this factor being generally affected by
the length of time in service.

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 17 AS 2467—2008

4.2.2.3 Mechanisms
The condition of mechanisms is affected by the number of operations, the environmental
surroundings, and the period of service.
4.2.2.4 Basis for the determination of intervals between maintenance operations
The intervals between maintenance operations may be based on the number of operations
performed or on fixed time intervals, the preferred basis being determined by the electrical,
mechanical and environmental duties imposed on the switchgear. In practice a combination
of these criteria may be used in the light of service experience with individual installations.
NOTE: An example of a typical fault openings form is given in Appendix B.
4.2.3 Records
It is important to keep records of the maintenance carried out. In this connection a record of
the ‘as found’ condition of the equipment can give an effective indication of the
maintenance required and a means of assessing any necessary change in frequency. A
review of these records may highlight design or application defects.
It should be noted that whilst excessive operations may dictate more frequent maintenance
the converse cannot normally be held to be true.
NOTE: Examples of typical maintenance record forms are given in Appendix B.
4.2.4 Routine maintenance
4.2.4.1 Basis for organization
It is preferable that routine maintenance be organized on the basis of regular inspections
supplemented at more extended intervals with operational checks and examination with
some dismantling as required. The inspections should ensure that no damage or distress has
been sustained in the course of operations whereas the examination enables the
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reconditioning of the contact system, the lubrication and adjustment of mechanisms

together with a more detailed inspection and testing of insulation to be carried out.
4.2.4.2 Diagnostic testing
It is recommended that where practicable and where the importance of the circuit deserves
special consideration, diagnostic testing be carried out to determine such characteristics as
timing, minimum operating voltage or pressures, and contact and insulation resistance.
These, by comparison with previous similar tests, will provide guidance to possible
deterioration and may indicate a need to vary maintenance intervals under particular service
conditions. (See also Section 11.)
4.2.4.3 Switchgear controlling continuously operated plant
For switchgear controlling continuously operated plant it may be necessary to coordinate
maintenance with the demands of the production program.
4.2.4.4 Different items of plant at a common location
In assessing maintenance intervals for different items of plant at a common location, e.g.
indoor and outdoor switchgear of different voltages at one station, the number of site visits
may be minimized by arranging for any different intervals of maintenance to be common
multiples of the period allocated to the items requiring most frequent attention.
4.2.5 Post-fault maintenance
Following fault operation it is good practice to inspect a circuit-breaker at the earliest
opportunity. Circuit-breakers complying with the requirements of AS 60947.2,
AS 62271.100 and AS 2184 are capable of performing at least a rated operating sequence at
the rated short-circuit current and more operations are usually permissible at lower values
without intermediate maintenance.

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 AS 2467—2008 18

Based on operating experience and on test evidence, the user, preferably after reference to
the manufacturer for information, may decide on a permitted operating sequence which may
in certain circumstances, e.g. vacuum circuit-breakers, be well in excess of the rated
operating sequence. It is necessary, however, to ensure that the permitted operating
sequence for particular circuit-breakers is not exceeded without post-fault maintenance
being carried out.

4.3 INSULATING OIL

4.3.1 General considerations
The interval between tests and between reconditioning of oil will depend on the nature and
frequency of operation of the switchgear under normal service conditions, together with
special considerations when frequent operations take place under low leading or lagging
power factor (capacitive or inductive load) conditions.
4.3.2 Environmental conditions
Environmental conditions may have a detrimental effect on insulating oil and special
attention should be paid to switchgear operating under adverse environmental conditions.
4.3.3 Deterioration and contamination
Deterioration of oil in switchgear depends mainly on the duty of the equipment and the
efficiency of its arc control device and the effects of the environment in which it is situated.
The optimum period between tests and reconditioning should be based on experience,
and/or consultation with the switchgear manufacturer.
The contamination of insulating oil may be a limiting factor on the allowable time between
maintenance operations on the main switchgear. (See also Clause 7.3.1.8.).
NOTES:
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1 The presence of carbon particles alone in oil does not necessarily indicate that the oil is in an
unacceptable condition.
2 Where insulating oil is used for insulation purposes only, special testing techniques such as
dissolved gas analysis may be necessary to detect deterioration of the oil or associated
insulation.
4.3.4 Normal maintenance tests
Electrical strength tests, and where ingress of moisture is likely, water content tests in
accordance with AS 1883 are recommended as the normal maintenance tests. There is
normally no necessity to test for acidity or flashpoint in switchgear insulating oil.
4.3.5 Auto-reclosing duty
Where switchgear is employed for auto-reclosing duty, the user may decide upon the
acceptable number of operations before oil is tested, by reference to operating experience,
test experience and/or consultation with the switchgear manufacturer.

4.4 RECOMMENDED INTERVALS

4.4.1 General
The recommended intervals given in Clauses 4.4.2 to 4.4.5 are a guide to the setting up of a
maintenance program. If no suitable experienced electrical engineer is available in the
user’s organization, assistance and/or advice should be obtained from other sources such as
the manufacturer of the equipment, or the local supply authority.
4.4.2 Operational check of a circuit-breaker
An operational check of circuit-breakers (see Clause 6.4) should be made at regular
intervals.

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 19 AS 2467—2008

4.4.3 Indoor switchgear

For switchgear installed in indoor situations which are dry and well ventilated, and where
the atmospheric conditions are not unduly corrosive and the switchgear is on normal
distribution duties, e.g. used infrequently to make or break normal load currents, the
following is given as a guide:
(a) Inspect regularly, with a maximum interval of 12 months.
(b) Examine normally at 5-year intervals. For switchgear controlling circuits without
alternative supplies and where interruptions would cause difficulties, this interval
may be extended but the intervals should be based on experience gained from
inspection and overhaul.
(c) Overhaul should only be carried out when and to the extent that inspection,
examination or diagnostic testing indicates it to be necessary. However, a maximum
interval of 15 years may be advisable.
NOTE: The intervals quoted are given as a guide and are based on a three-stage maintenance
policy of inspection, examination and overhaul. Where the policy is based on two stages, i.e.
inspection and overhaul, the maximum advisable interval between overhauls should be reduced to
10 years.
4.4.4 Outdoor switchgear
For outdoor switchgear where the atmospheric conditions of the site are reasonably clean
and the switchgear is not subject to excessive pollution such as occurs in some industrial or
coastal areas, for normal distribution duties the intervals given in Clause 4.4.3 should be
considered, but these may need to be reduced to cater for any adverse conditions.
4.4.5 Frequent operation or adverse atmospheric conditions
For switchgear which is frequently operated, or situated in adverse atmospheric conditions,
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the intervals between maintenance operations will be less than those stated in Clause 4.4.3.
In the case of circuit-breakers operated frequently to control, e.g. an electric arc furnace or
similar equipment, the intervals between maintenance operations could be measured in
weeks.
In such cases it may be preferable to relate the intervals to the number of switching
operations rather than time.
NOTE: See Clause 5.7 for a summary of recommended maintenance operations.

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 AS 2467—2008 20

S E C T I ON 5 M A I N T E N A N CE O F
SWI T C H GE A R I N T E N D E D T O O PE RA T E A T
VO L TAGES UP TO 1000 V a.c. AN D
1 20 0 V d . c.

5.1 PRE-MAINTENANCE REQUIREMENTS AND PRECAUTIONS

5.1.1 Safety of personnel
To establish safe working conditions for maintenance of switchgear operating at voltages up
to 1000 V a.c. and 1200 V d.c. the requirements given in Sections 2 and 3 should be
complied with.
5.1.2 Equipment to be rendered inoperative
It is preferable that all equipment to be worked on be made dead and isolated and all
closing and opening devices be made inoperative. If it is not practicable to make the
equipment dead and isolated, at least all closing and opening devices should be made
inoperative. This can usually be achieved as follows:
(a) For closing devices—by the discharge of any stored energy devices and by the
removal of fuses or links in the control closing circuits.
(b) For tripping devices—by the tripping of any tripping devices and by the removal of
fuses or links in the tripping and auxiliary circuits. Any stored energy devices should
have their energy discharged.
5.1.3 Manufacturer’s operation and maintenance instructions
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The equipment manufacturer’s operation and maintenance instructions should be read in

conjunction with this Standard.
5.1.4 Replacement parts
It is important to ensure the suitability and interchangeability of replacement parts.

5.2 FREQUENCY OF MAINTENANCE

The interval which can be allowed between consecutive maintenance operations on
switchgear for operation at voltages up to 1000 V a.c. and 1200 V d.c. will depend on the
operating conditions of the circuits controlled. Section 4 outlines the criteria which should
be considered when the intervals between maintenance operations are being decided.

5.3 DIAGNOSTIC TESTING

Where practicable, the maximum use should be made of diagnostic testing techniques to
indicate the condition of equipment and to prolong the intervals between dismantling. It is
important that records be kept of all diagnostic tests so that comparisons can be made and
trends estimated; ‘tick lists’ alone which indicate only that measurements have been taken
are not sufficient.
Diagnostic techniques applicable to switchgear are given in Section 11.

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 21 AS 2467—2008

5.4 ROUTINE MAINTENANCE

5.4.1 Inspection
5.4.1.1 General inspection
A general inspection of the electrical station should be made, attention being given to
general cleanliness, heating ventilation, and other relevant requirements detailed in
Section 3. During this inspection, the condition of weather seals, signs of corrosion, leakage
of oil or compound, any unusual smell which may indicate overheating, and any noise
which may indicate electrical discharge or looseness of components should be investigated.
Also, as far as is reasonably practicable, any external insulation, trip mechanism, shutter
mechanism earth connection and other visible parts should be inspected for any signs of
abnormality.
Inspections should be made to ensure that any ancillary equipment, spare fuses, special
tools or other equipment required for the operation of the switchgear are available and in
good order.
5.4.1.2 Inspection of specific items of equipment
Attention should be given to the items where a clause number is shown in column 3 of
Table 5.1 (see Clause 5.7).
5.4.2 Examination and overhaul
5.4.2.1 General
Overhauls should only be carried out on such items that an inspection, examination or
manufacturer’s recommendation indicates to be necessary. Clauses 5.4.2.2 to 5.4.2.13 give
operations which may be required to be carried out during maintenance.
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5.4.2.2 Cleaning
All loose external dirt should first be removed. In the cleaning of switchgear it is most
important not to use what is generally known as cotton waste. Material used for this
purpose should be clean and free from loose fibres, metallic threads and similar particles.
Brushes and blower nozzles should contain no metallic material.
Care should be taken to prevent loose parts, tools metal filings or dirt falling into the
apparatus.
Cleaning fluids should be very carefully selected to ensure compatibility with organic
insulation plastics, valve gear and bearings, rubber and synthetic ‘O’ rings, and other
materials used in the construction of the equipment. They should also be safe for use by
personnel.
5.4.2.3 Insulation
Insulation should be inspected, cleaned and renewed where necessary. Porcelain and
moulded insulation should be inspected for cracks or other defects. Bonded and laminated
fibrous and other organic insulation should be inspected for signs of tracking, treeing,
blistering, delamination or mechanical damage. On this type of equipment, which often
cannot be isolated, insulation resistance tests are only necessary where the insulating
material is suspect or when the connected circuits are to be tested.
For further information on the maintenance and testing of insulation see Section 14.
5.4.2.4 Equipment enclosures
Operation of any heaters should be verified, and any anti-condensation finishes inspected
for signs of deterioration.

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 AS 2467—2008 22

5.4.2.5 Contacts
The following recommendations apply to contacts:
(a) Contacts should be examined for burning, overheating, misalignment or other damage
and reconditioned or renewed as required. It should be verified, by means of special
tools if provided, that bolted or wedge type contacts are correctly tightened.
Overheating may be caused by overloading, loose connections, insufficient contact
force, ineffective fuse-link contact or lack of alignment of switch contacts, and
sometimes may be detected only with the equipment on load.
(b) Slight discoloration or burning of bare copper or copper alloy contacts is not
necessarily harmful but may be removed by suitable abrasive cloth or a fine file. The
amount of material removed from contacts should be kept to a minimum and the
manufacturer’s recommended profile should be maintained. It is important that the
spring force between the contact surfaces should not be significantly reduced.
Modern high-pressure point or line contacts will normally carry their rated current
satisfactorily even if there is some pitting of the surface. Large beads or ridges on the
contacting members that would seriously impede closing or opening should be
removed.
(c) It is usually undesirable to attempt to clean or dress tipped or plated contacts and the
manufacturer’s recommendations should be followed. Silver or silver-plated contacts
seldom require cleaning despite a black appearance. If it is required to clean them,
silver polish may be used.
(d) When contacts are refitted, renewed or refurbished, the contact force, alignment and
wipe should be verified.
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(e) Any flexible braids should be inspected, especially for fraying at the terminations,
and renewed if necessary. Where exposed to the atmosphere, the braids may be
treated with a suitable protective compound which will not impair their flexibility.
(f) Any recommendations of the manufacturer for treatment of the contacts should be
followed. Caution should be taken with the use of lubricants in dusty situations.
5.4.2.6 Arc-control devices and interpole barriers in the vicinity of the arc
Arc-control devices and interpole barriers in the vicinity of the arc should be examined and
cleaned or, if badly burned, renewed.
Where the surface finish of an arc-control device is critical to its performance, the device
should not be abraided during cleaning, but renewed.
Any air-puffer device should be checked for correct operation.
As far as is reasonably practicable, arc-control devices should be examined to ensure that
they are securely fastened, correctly adjusted and electrically connected. All adjustments
should be carried out in accordance with the manufacturer’s instruction.
5.4.2.7 Mechanisms
Mechanisms should be cleaned and examined and any worn parts renewed. It should be
verified that circlips are correctly seated and that split pins are opened.
5.4.2.8 Indicating devices and interlocks
The following recommendations apply to indicating devices and interlocks:
(a) Indicating devices such as mechanical ‘ON’ and ‘OFF’ indicators, semaphores, etc.
should be inspected to ensure that they are in good order and operating correctly.
(b) Correct operation of any interlocks and padlocking devices should be verified and any
adjustments required should be made.

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 23 AS 2467—2008

Provided the necessary precautions have been taken, it should also be verified that
interlocks inhibit the incorrect actions.
5.4.2.9 Connections
It should be verified that all joints are sound and that good contact is maintained on current-
carrying, main earth and secondary earth connections.
NOTE: Care should be exercised when re-making aluminium connections (see AS 62271.301).
5.4.2.10 Fuses
It should be verified that fuse connections are tight and that the rating of fuses is correct.
Fuse-links should be inspected for signs of deterioration.
The fusible elements of semi-enclosed fuses should be renewed where deterioration is
suspected.
5.4.2.11 Cable terminations
Any compound-filled cable termination associated with the switchgear should be inspected
for compound leakage or distortion and any defect corrected. Cable tails and risers should
be inspected for overheating of connections or distortion.
5.4.2.12 Contactors
In addition to any relevant previous operations, the following should be carried out:
(a) Remove loose particles and dust from arc chutes and replace the arc chutes where
necessary. Inspect contacts and springs. Contacts should normally be allowed to bed
in until erosion necessitates replacement.
(b) Pivots should be lightly lubricated if required (refer to manufacturer’s instructions)
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and armature pole faces cleaned. It should be verified that any shading rings are in
position.
(c) Contacts should be free to operate and should not foul the arc chutes.
(d) The alignment and security of the tube and flexible connections of mercury tube
contacts should be verified.
5.4.2.13 Busbars and busbar chambers
Any barriers and supports should be examined as is reasonably practicable, and in
accordance with the following:
(a) Air insulated equipment For air insulated equipment the examination should include
any dismantling required to enable connections to be inspected and any chambers to
be cleaned.
(b) Compound filled equipment For compound filled equipment, the examination should
be limited to the verification of the filling level and an inspection for signs of leakage
of the compound, moisture ingress and irregularities on the surface of the compound.
5.4.2.14 Final verification
Before the equipment is returned to service, the following should be done:
(a) Verification of tightness of circuit and earth connections.
(b) Verification of insulation resistance of circuit including auxiliary wiring.
(c) An operational check.

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 AS 2467—2008 24

5.5 POST-FAULT MAINTENANCE

Depending on the design and duty of the switchgear, inspection may be necessary after
operation on fault. Where such an inspection is necessary attention should be given to the
following:
(a) Cleaning Insulation and other parts should be cleaned and inspected for signs of
cracking, burning, tracking or other damage.
(b) Contacts and arc control devices Contacts and arc control devices should be
inspected for burning or other damage and reconditioned or renewed where necessary.
The contact force, alignment and wipe should be verified. (See also Clause 5.4.2.5.)
(c) Mechanisms The mechanism should be checked for correct operation.
(d) Insulation resistance The insulation resistance should be checked before the
equipment is returned to service.

5.6 MAINTENANCE OF AUXILIARY EQUIPMENT

Recommendations applicable to auxiliary equipment which may form part of the switchgear
are given in Section 12.

5.7 SUMMARY OF MAINTENANCE OPERATIONS

The maintenance operations recommended for switchgear intended for operation at voltages
up to 1000 V a.c. and 1200 V d.c. are summarized in Table 5.1. A reference to the clause
number in column 2, 3, 4 or 5 indicates that this type of maintenance operation is
appropriate.
NOTE: See Clause 6.9 for a summary of recommended maintenance operations.
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 25 AS 2467—2008

TABLE 5.1
MAINTENANCE OPERATIONS FOR SWITCHGEAR INTENDED FOR
OPERATION AT VOLTAGES UP TO 1000 V a.c. AND 1200 V d.c.*
1 2 3 4 5
Routine maintenance
Maintenance operation Pre-maintenance Inspection Examination Post-fault
requirements and overhaul maintenance
Safety of personnel 5.1.1
Equipment to be replaced inoperative 5.1.2
General inspection 5.4.1.1 5.4.1.1
Diagnostic testing 5.3 and
Section 11
Cleaning 5.4.2.2 5.5
Insulation 5.4.2.3 5.4.2.3
Enclosures 5.4.2.4
Contacts 5.4.2.5 5.4.2.5 5.5
Arc control devices 5.4.2.6 5.4.2.6 5.5
Mechanisms 5.4.2.7 5.4.2.7 5.5
Indicating devices and interlocks 5.4.2.8 5.4.2.8
Connection 5.4.2.9
Fuses 5.4.2.10 5.4.2.10
Cable terminations 5.4.2.11 5.4.2.11
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Contactors 5.4.2.12
Busbars and busbar chambers 5.4.2.13
Final verification 5.4.2.14 5.4.2.14
Auxiliary equipment Section 12 Section 12 5.5
* The number quoted in the columns refers to the appropriate clause number.

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 AS 2467—2008 26

SECT I O N 6 MA I N T E N A N CE O F A I R- B RE A K
SWITC H G E A R I N T E N D E D FO R O PE RA T I O N A T
VO L TAGES ABOVE 10 00 V a.c. AN D
1 2 0 0 V d . c.

6.1 PRE-MAINTENANCE REQUIREMENTS AND PRECAUTIONS

6.1.1 Safety of personnel
To establish safe working conditions for maintenance of switchgear operating at voltages
above 1000 V a.c. and 1200 V d.c., the requirements given in Sections 2 and 3 should be
complied with.
6.1.2 Equipment to be rendered inoperative
Power-closed switchgear together with any associated remote controlling equipment should
be rendered inoperative. This can usually be achieved by taking the action described in (a)
to (h) below as appropriate:
(a) Solenoid-closed switchgear—the main solenoid supply should be isolated.
(b) Spring-closed switchgear—the spring should be discharged, and for a motor-wound
spring-closing mechanism, the motor supply should first be isolated.
(c) Pneumatically-closed switchgear—the air system of the switchgear concerned should
be exhausted and locked off, the local air receiver drain valves being left open and
where practicable locked open during the whole of the time that work is being carried
out on the gear.
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For switchgear of the fully pressurized type, the switchgear should be in the
manufacturer’s recommended position, open or closed, for the draining of gas from
the receiver. If necessary the manufacturer’s instructions should be consulted.
NOTE: It is important to note that freezing of the drain valve can occur during draining so
that although air has ceased to pass through it, the pressure in the receiver may still be above
atmospheric pressure. To ensure that the air pressure has been completely released, the
pressure gauge should be checked to ensure that it is reading zero, i.e. atmospheric pressure.
(d) Stored energy devices—should be discharged.
(e) Tripping devices—should be tripped.
(f) Fuses or links—should be removed.
(g) Removable or withdrawable switchgear—before any work is carried out on the fixed
isolating contacts, the contacts should be isolated and earthed.
(h) Shutters—any shutters or other devices preventing access to isolating contacts which
may be live, should be locked closed.
6.1.3 Manufacturer’s operation and maintenance instructions
The equipment manufacturer’s operation and maintenance instructions should be read in
conjunction with this Standard.
6.1.4 Replacement parts
The suitability and interchangeability of replacement parts should be verified.

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 27 AS 2467—2008

6.2 FREQUENCY OF MAINTENANCE

The interval which can be allowed between consecutive maintenance operations on
switchgear for operation at voltages above 1000 V a.c. and 1200 V d.c. will depend on the
operating conditions of the circuits controlled. Section 4 outlines the criteria which should
be considered when the intervals between maintenance operations are being decided.

6.3 DIAGNOSTIC TESTING

Where practicable the maximum use should be made of diagnostic testing techniques to
indicate the condition of equipment and to prolong the intervals between dismantling. It is
important that records be kept of all diagnostic tests so that comparisons can be made and
trends estimated; ‘tick lists’ alone which indicate only that measurements have been taken
are not sufficient.
Diagnostic techniques applicable to switchgear are given in Section 11.

6.4 OPERATIONAL CHECK

Where practicable every circuit-breaker should be tripped and re-closed at regular intervals,
to verify that it is capable of satisfactory operation. The tripping should be initiated by the
electrical operation of the trip coil.
The interval between operational checks may vary from less than 6 months to more than 5
years depending on the operating conditions.

6.5 ROUTINE MAINTENANCE

6.5.1 Inspection
6.5.1.1 General inspection
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A general inspection of the substation or switchroom should be made, attention being given
to general cleanliness, heating, ventilation and other relevant requirements detailed in
Section 3. During this inspection, the condition of weather seals, signs of corrosion, leakage
of oil or compound, any unusual smell which may indicate overheating, and any noise
which may indicate electrical discharge or looseness of components should be investigated.
Also, as far as is reasonably practicable, any external insulation, trip mechanism, shutter
mechanism, gas vents, earth connection and other visible parts should be inspected for any
signs of abnormality.
Inspections should be made to ensure that any ancillary equipment, spare fuses, special
tools or other equipment required for the operation of the switchgear are available and in
good order.
6.5.1.2 Inspection of specific items of equipment
Attention should be given to the items where a clause number is shown in column 3 of
Table 6.1 (see Clause 6.9).
6.5.2 Examination and overhaul
6.5.2.1 General
Overhauls should only be carried out on such items as an inspection, examination or
manufacturer’s recommendation indicates to be necessary.
Clauses 6.5.2.2 to 6.5.2.21 give operations which may be required to be carried out during
maintenance.

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 AS 2467—2008 28

6.5.2.2 Cleaning
All loose external dirt should first be removed. To avoid ingress of dirt into any internal
portion of the circuit-breaker, any joint or gasket should be cleaned prior to commencing
any dismantling. This is particularly important in the case of pneumatic valve gear, as
relatively small particles of dirt can cause damage, leakage or malfunctions.
In the cleaning of switchgear it is most important not to use what is generally known as
cotton waste. Materials used for this purpose should be clean and free from loose fibres,
metallic threads and similar particles. Brushes and blower nozzles should contain no
metallic material.
Care should be taken to prevent loose parts, tools, metal filings or dirt falling into the
apparatus.
Cleaning fluids and lubricants applied after cleaning should be very carefully selected to
ensure compatibility with organic insulation, plastics, valve gear and bearings, rubber and
synthetic ‘O’ rings, and other materials used in the construction of the equipment. They
should also be safe for use by personnel.
6.5.2.3 Insulation
Insulation should be inspected, cleaned and renewed where necessary. Porcelain and
moulded insulation should be inspected for cracks or other defects. Bonded and laminated
fibrous and other organic insulation should be inspected for signs of tracking, treeing,
blistering, delamination or mechanical damage. Insulation resistance tests are strongly
recommended as these give an indication of the condition of the insulation.
For further information on the maintenance and testing of insulation see Section 14.
6.5.2.4 Equipment enclosures
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Operation of any heaters should be verified and any anti-condensation finishes inspected for
signs of deterioration.
6.5.2.5 Contacts
The following recommendations apply to contacts:
(a) Contacts should be examined for burning or other damage and reconditioned or
renewed as required. It should be verified that any backing springs are exerting the
correct force and that the contacts are in correct alignment.
It will be expected that the arcing contacts will show signs of burning and erosion,
but this will not be harmful provided that it is not excessive and provided that the
correct lead between the arcing and main contacts can be obtained. The security of
any arc-resisting tips should be checked. It should be remembered that the normal
duty of arcing tips is to carry the arc root but if excessive burning and/or erosion is
present the tips should be renewed.
(b) Hinge contacts should be examined for any signs of overheating, burning, welding or
other damage, and be reconditioned, adjusted or replaced as necessary. If such
damage is found, the cause should be investigated. Contacts should be inspected for
signs of arcing in other than normal places.
(c) Slight discoloration or burning of bare copper or copper-alloy contacts is not
necessarily harmful but may be removed by suitable abrasive cloth or a fine file. The
amount of material removed from contacts should be kept to a minimum and the
manufacturer’s recommended profile should be maintained. If necessary, the contacts
should be renewed. It is important that the spring force between the contact surfaces
not be significantly reduced.

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 29 AS 2467—2008

Modern high-pressure point or line contacts will normally carry their rated current
satisfactorily even if there is some pitting of the surface. Large beads or ridges on the
contacting members that would seriously impede closing or opening should be
removed.
(d) For circuit-breakers using high-pressure contacts, e.g. high-speed circuit-breaker, or
special ‘tipped’ contacts, it is usually undesirable to attempt to clean or to dress the
contacts, and the manufacturer’s recommendations should be followed. Silver or
silver-plated contacts seldom require cleaning despite a black appearance. If it is
required to clean them, silver polish may be used.
(e) For laminated wiping contacts, the manufacturer’s recommendations should be
followed.
(f) When contacts are refitted, renewed or refurbished, contact force, alignment and wipe
should be verified.
(g) Any flexible braids should be inspected especially for fraying at the terminations, and
renewed if necessary. Where exposed to the atmosphere, the braids may be treated
with a suitable protective compound which will not impair their flexibility.
(h) The manufacturer’s recommendations should be followed concerning lubrication of
contacts pivots and hinge pins.
6.5.2.6 Arc-control devices and interpole barriers in the vicinity of the arc
Arc-control devices and interpole barriers in the vicinity of the arc should be examined and
cleaned or, if badly burned, renewed.
Where the surface finish of an arc-control device is critical to its performance, the device
should not be abraided during cleaning, but renewed.
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Any air-puffer device should be checked for correct operation.

As far as is reasonably practicable, arc-control devices should be examined to ensure that
they are securely fastened, correctly adjusted and electrically connected. All adjustments
should be carried out in accordance with the manufacturer’s instructions.
6.5.2.7 Mechanisms
The following recommendations apply to mechanisms:
(a) General During inspection or examination of mechanisms care should be taken to
avoid the fingers being trapped and to avoid the possibility of anyone being struck by
moving parts.
(b) Circlips and split pins It should be verified that circlips are correctly seated and that
split pins are opened.
(c) Tripping mechanism The tripping mechanism should be cleaned and examined and
any worn parts renewed.
It is particularly important to ensure that rolling or sliding surfaces in the trip
mechanism are free from dried-up lubricant. The mechanical items of the tripping
mechanism should be inspected, lubricated sparingly with the recommended lubricant
and adjusted as required. Particular care should be taken with plastics bearings or
components since the use of an incorrect lubricant can often have a deleterious effect.
Correct operation should be verified.
Trip coil plungers should be inspected for free movement but should not be
lubricated.
Extreme care should be taken to verify that the adjustments comply with the
manufacturer’s instructions.

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 AS 2467—2008 30

(d) Closing mechanism The closing mechanism should be cleaned and examined and
any worn parts renewed. It should be lubricated as necessary, and all surplus oil and
grease removed.
The mechanical details of the closing mechanism should be examined and the correct
operation of any damping devices verified. For spring closing gear, special attention
should be paid to ratchet wheels and pawls, which should be examined for broken or
chipped teeth.
Where motor-wound springs are employed, the motor and its connections should be
examined and the reduction gear treated with the recommended lubricant.
Inspect line valves and joints of air-closing mechanisms. Recording of mechanism
settings may indicate the progression of wear or relaxation.
NOTE: There are statutory obligations to inspect air receivers (pressure vessels) periodically,
at which time safety and reducing valves, if fitted, should also be inspected.
(e) Interpole linkages Interpole linkages usually have carefully fitted linkage pins, and
minimum backlash mechanisms. It is important that these features be examined and
adjusted as required.
6.5.2.8 Auxiliary switches, indicating devices and interlocks
The following recommendations apply:
(a) Auxiliary switches Auxiliary switches should be kept in clean and sound condition
because upon them depends the correct functioning of other items of equipment,
including protective gear.
The contacts should be inspected and cleaned, and renewed if necessary. Where
possible, correct contact force, freedom of operating links and correct timing of
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contacts in relation to the circuit-breaker contacts should be verified.

(b) Indicating devices Indicating devices such as mechanical ON and OFF indicators,
semaphores, etc., should be inspected to ensure that they are in good order and
operating correctly.
(c) Interlocks Interlocks and locking devices should receive particular attention,
especially those associated with earthing and testing facilities. A strained or worn
device may result in a dangerous condition.
Provided the necessary precautions have been taken, it should be verified that any
incorrect operation is satisfactorily inhibited. Lubricant should be applied as
necessary.
(d) Contact timing Particular attention should be paid to the required timing of the
auxiliary contacts controlling the trip circuit.
6.5.2.9 Isolating contacts (of removable equipment)
Isolating contacts should be cleaned, inspected for signs of overheating or corrosion, and
renewed or reconditioned where necessary. They should be lubricated sparingly, if required,
with the recommended lubricant. Caution should be taken with the use of lubricants in
dusty situations.
Removable plug contacts for busbar selection should be withdrawn and treated in the same
manner.
The contact penetration and alignment should be verified.
6.5.2.10 Overload devices and protective relays
Recommendations for routine maintenance are given separately in Section 13.

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 31 AS 2467—2008

6.5.2.11 Instrument and protective transformers

Recommendations for routine maintenance are given separately in Section 12 and 13.
6.5.2.12 Control relays or contactors
With the control and main solenoid or motor circuit isolated, the mechanical parts of
control relays or contactors should be inspected for free movement. Loose particles and
dust should be removed from arc chutes and the arc chutes replaced where necessary.
Contacts should be inspected and renewed where necessary.
Any flexible braids should be inspected, especially for fraying at the terminations, and
renewed when necessary. Where exposed to external atmosphere, the braids may be treated
with a suitable protective compound which will not impair their flexibility.
6.5.2.13 Connections
It should be verified that all joints are sound and that good contact is maintained on current-
carrying, main earth and secondary earth connections.
NOTE: Care should be exercised when re-making aluminium connections (see AS 2067).
6.5.2.14 Secondary wiring and fuse
It should be verified that connections of secondary wiring and fuses are tight, that good
contact is maintained, and that terminal boxes are free from dirt and moisture. Insulation
resistance and continuity of wiring to the fuses, instrument transformers, relays,
instruments, motors and other associated items should be verified.
All contacts including plug and socket contacts should be cleaned and lubricated sparingly
with the recommended lubricant. Caution should be taken with the use of lubricants in
dusty situations.
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Fuse-links should be inspected for signs of deterioration.

Fixed contacts carrying the fuses should be checked for satisfactory contact and cleaned if
necessary.
6.5.2.15 Heaters
The correct operation of any heaters should be verified.
6.5.2.16 Isolators and earthing switches
The following recommendations should be adhered to:
(a) Verification of operation The correct operation of isolators and earthing switches
should be verified. The contacts should be examined for signs of burning or
overheating and contact force should be verified.
(b) Verification of interlocking Provided the necessary precautions have been taken, the
correct interlocking between these switches and the circuit-breaker or other
associated switchgear should be verified.
Where ‘safe-to-operate’ lamps are used as an alternative to interlocking, their correct
operation should be verified.
(c) Linkages Linkages should be carefully cleaned and a suitable lubricant should be
applied. The correct alignment of drive links and operating rods should be verified
and adjusted as necessary.
It should be verified that all poles operate freely and simultaneously and that the main
contacts are held positively in the fully engaged position when the operating linkage
is in the ‘ON’ position. Conversely it should be verified that the main contacts are
fully open when the operating linkage is in the ‘OFF’ position.

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 AS 2467—2008 32

(d) Contacts Main and auxiliary contacts should be inspected, cleaned or renewed and
lubricated sparingly, if required, with the recommended lubricant. It should be
verified that contact backing or garter springs exert correct force and that contacts are
in correct alignment.
NOTE: Infrared detection techniques may be of assistance in the assessment of contact
condition (see Clause 11.3.2).
(e) Hinged contact springs The force of hinged contact springs should be verified and
lubricant should be applied to the hinges. Flexible connections should be inspected
for fraying, especially at the terminations, and for deterioration of any protective
oversheaths. Protective compound may be applied to protect bare copper flexibles in
outdoor conditions. The security of linkages should be verified and a lubricant should
be applied to the pivots of any supporting pantograph.
(f) Arc horns Arc horns should be inspected for damage and security of fixings should
be verified. It should also be verified that the horn wipes lightly through the opening
stroke and does not foul the closing stroke.
(g) Insulation Insulation should be carefully cleaned and inspected for cracks or other
damage and any defective components renewed.
(h) Operating rod insulators Operating rod insulators such as wood laminates should be
examined for both mechanical and electrical condition and should be refurbished or
changed as necessary.
(i) Joints and connections It should be verified that all joints and connections,
including earth connections are sound.
NOTES:
1 Care should be exercised when re-making aluminium connections (see AS 62271.301).
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2 Infrared detection techniques may be of assistance in the assessment of the condition of

joints and connections.
6.5.2.17 Shutters
The operation of any shutter mechanism should be verified. This should normally be carried
out immediately after removal of the equipment from its housing or immediately prior to
energizing.
The operating mechanism and associated linkage should be lubricated sparingly, as
recommended by the manufacturer.
6.5.2.18 Switchgear spouts
Spouts should be examined and cleaned where necessary, and surfaces inspected for signs
of mechanical or electrical deterioration.
Immediately prior to returning the switchgear to the service position, a visual inspection of
the spouts should be carried out.
6.5.2.19 Busbars and busbar chambers
Any barriers and supports should be examined as is reasonably practicable, and in
accordance with the following:
(a) Air-insulated equipment For air-insulated equipment, the examination should
include any dismantling required to enable connections to be inspected and any
chambers to be cleaned.
(b) Compound-filled equipment For compound-filled equipment, the examination should
be limited to the verification of the filling level and an inspection for signs of leakage
of the compound, moisture ingress and irregularities on the surface of the compound.

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 33 AS 2467—2008

To check for possible deterioration of the compound, the insulation resistance should
be recorded at regular intervals, as a guide say every 10 years. Any significant change
in values may require a thorough investigation of the condition of the compound.
6.5.2.20 Weather shields
It should be verified that any weather shield fitted to the equipment is securely fixed and
that it is in a serviceable condition before the equipment is re-energized.
6.5.2.21 Final verification
Before the equipment and auxiliary apparatus are returned to service, an insulation
resistance test should be carried out (see Section 12), followed by an operational check.

6.6 POST-FAULT MAINTENANCE

Depending on the design and duty of the switchgear (see Section 4), inspection may be
necessary after operation on fault. Where such an inspection is necessary, attention should
be given to the following:
(a) Cleaning Insulation and other parts liable to deposition from metal vapour should be
cleaned and inspected for signs of cracking, burning, tracking or other damage.
(b) Contacts and arc-control devices Contacts should be inspected for burning or other
damage and reconditioned or renewed if necessary. Contact force, alignment and wipe
should be verified.
To remove traces of metal deposits, it will generally be found necessary to remove
the arc-control devices, and recondition or renew them.
(c) Mechanisms It should be verified that the mechanism operates correctly and
particular attention should be paid to settings and clearances after contact or arc-
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control devices are replaced.

(d) Insulation resistance A test should be made of the insulation resistance before
putting the switchgear back into service.

6.7 MAINTENANCE OF AUXILIARY EQUIPMENT

Recommendations applicable to auxiliary equipment which may form part of the switchgear
are given in Section 12.

6.8 HIGH-VOLTAGE FUSE CONNECTIONS AND ASSOCIATED LINKAGE

It should be verified, where applicable, that the operation of a single fuse causes all other
poles to open and that the manual ON/OFF trip mechanism functions correctly.
If a change of fuse is required, the new one shall be inserted correctly with the striker pin
adjacent and in alignment with the operating mechanism. The linkage operation should then
be checked. The approved fuse for the particular equipment shall always be fitted.
When replacing a blown fuse in a multiphase set, the remaining fuses should be replaced or,
subject to advice from the fuse manufacturer, the resistance of their elements checked
against a new fuse for evidence of deterioration.

6.9 SUMMARY OF MAINTENANCE OPERATIONS

The maintenance operations recommended for air-break switchgear intended for operation
at voltages above 1000 V a.c. and 1200 V d.c. are summarized in Table 6.1. A reference to
the clause number in column 2, 3, 4 or 5 indicates that this type of maintenance operation is
appropriate.

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 AS 2467—2008 34

TABLE 6.1
MAINTENANCE OPERATIONS FOR AIR-BREAK SWITCHGEAR INTENDED
FOR OPERATION ABOVE 1000 V a.c. AND 1200 V d.c.*
1 2 3 4 5
Routine maintenance
Pre-maintenance Post-fault
Maintenance operation Examination
requirements Inspection maintenance
and overhaul
Safety of personnel 6.1.1
Equipment to be rendered inoperative 6.1.2
Diagnostic testing 6.3 6.3
Operational check 6.4 6.4 6.4
General inspection 6.5.1.1 6.5.1.1
Cleaning 6.5.2.2 6.6
Insulation 6.5.2.3 6.5.2.3 6.6
Enclosures 6.5.2.4 6.5.2.4
Contacts 6.5.2.5 6.6
Arc-control devices and interpole barriers 6.5.2.6 6.6
Mechanisms 6.5.2.7 6.6
Auxiliary switches 6.5.2.8
Indicating devices and interlocks 6.5.2.8
Isolating contacts 6.5.2.9
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Overload devices, protective relays Section 13 Section 13

Instrument and protective transformers Sections 12
and 13
Control relays or contactors 6.5.2.12
Connections 6.5.2.13
Secondary wiring and fuses 6.5.2.14
Heaters 6.5.2.15
Isolators and earthing switches 6.5.2.16 6.5.2.16
Shutters 6.5.2.17
Switchgear spouts 6.5.2.18 6.5.2.18
Busbars and busbar chambers 6.5.2.19
Weather shields 6.5.2.20
Final verification 6.5.2.21 6.5.2.21 6.5.2.21
Auxiliary equipment Section 12 Section 12
High-voltage fuse connections and 6.8 6.8
associated links
* The numbers quoted in the columns refer to the appropriate clause number herein.

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 35 AS 2467—2008

SE C T I ON 7 M A I N T E N A N CE O F O I L
S W I T CH G E A R

7.1 APPLICATION OF SECTION

Section 6 applies to the maintenance of oil switchgear with the additions and modifications
given in Clauses 7.2 to 7.5.
NOTE: See Clause 7.5 for a summary of recommended maintenance operations.

7.2 SPECIAL PRECAUTIONS FOR OIL SWITCHGEAR

The following special precautions should be observed:
(a) Where oil is or has been directly exposed to the atmosphere, smoking or naked flames
should be prohibited.
(b) Particular care should be taken when personnel are required to enter bulk oil circuit-
breaker tanks.
(c) Under no circumstances should the switchgear be operated with the tank down or
devoid of oil, without first referring to the manufacturer’s instructions and taking all
necessary safety precautions.

7.3 ROUTINE MAINTENANCE

Clause 6.5 applies with the following conditions and modifications.
7.3.1 Examination and overhaul
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7.3.1.1 Cleaning
For the cleaning of oil compartments it is good practice to use only chamois leather or
plastics sponges.
7.3.1.2 Insulation
Oil-filled bushings should be inspected for leaks and the oil level should be checked and
corrected if necessary.
Any water sumps of oil barrier bushings should be drained.
NOTE: As conducting films can occur on the bushings of outdoor switchgear special cleaning
liquids may be recommended by the manufacturer.
7.3.1.3 Arc-control devices
The following recommendations apply to arc-control devices:
(a) These should be inspected or examined and cleaned and, if there is a change in
volume or orifice size, or if they are badly burned, they should be renewed. Care
should be taken that vent holes and contact orifices are cleaned and the devices
should be flushed out with clean oil before being refitted. Retightening of any
assembly bolts may be necessary.
(b) Arc-control devices made from compressed fibrous materials which cannot be cleaned
without abrasion should be renewed. Other materials should be treated in accordance
with the manufacturer’s instructions.
Assemblies which have been removed should be immersed in clean oil during work
delays to prevent entry of moisture.
(c) Any resistors and connections should be checked for continuity or resistance value.

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 AS 2467—2008 36

(d) As far as is reasonably practicable arcing tips and arc-control devices should be
inspected to ensure that they are securely fastened, correctly adjusted and electrically
connected.
(e) Vent holes and contact orifices shall be in their correct positions relative to the
contact system when arc control devices are being refitted.
(f) All adjustments should be carried out in accordance with the manufacturer’s
instruction.
7.3.1.4 Venting, gas seals and breathers
The venting system should be checked to ensure that a free passage for oil and gases exists.
Where there is a joint between fixed and movable portions of the gear ensure that it is in
sound condition. In no circumstances should the vents be made larger than the design
allows.
The condition of dehydrating agents if incorporated in breathers should be checked.
7.3.1.5 Mechanisms
Clause 6.5.2.7 applies with the following additional item relating to uncontrolled openings:
uncontrolled closing or opening operations with the tank removed or empty of oil are
undesirable unless the manufacturer’s instructions specifically indicate otherwise.
7.3.1.6 Interpole linkages
The following recommendations apply to interpole linkages:
(a) Interpole linkages usually have carefully fitted linkage pins, and minimum backlash
mechanisms. It is important that these features be examined and adjusted as required,
to ensure minimum spread of timing between poles. Any deterioration in this respect
will usually be indicated in the timing test.
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(b) The manufacturer’s instructions for the setting dimensions of the interpole linkages
should be verified, and all nuts and bolts should be tight and all pivot pins secure.
(c) It should be verified that all fixings are tight and all pivot pins are secure.
(d) On circuit-breakers fitted with mechanical or pneumatic intertripping between poles,
the correct function should be verified by initiating operations (close and open) of
each pole in turn and ensuring that in each case the remaining two poles follow suit.
NOTE: Interpole linkages should not be altered unless essential adjustments are required.
7.3.1.7 Dashpots associated with interpole linkages
The following recommendations apply:
(a) Malfunction of dashpots associated with interpole linkages is usually only shown up
by an appropriate travel record during the timing test and unless such a record is
available and indicates satisfactory operation, the dashpots should be carefully
inspected.
(b) For oil type dashpots, it should be verified that the oil level is correct.
(c) For air type dashpots, it should be verified that bleed holes are not blocked and that
clearances are satisfactory.
7.3.1.8 Insulating oil (See also Clause 4.3)
The following recommendations apply:
(a) Testing and sampling A representative sample of oil should be taken and tested in
accordance with AS 1883, with suitable variation for high viscosity oil. Oil which
does not comply with the prescribed tests should be replaced with oil meeting the
required standard. The oil level should be maintained to the prescribed level.

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 37 AS 2467—2008

In addition to the above routine maintenance, regular inspections, where practicable,

should be made of oil levels.
(b) Replacement of oil It is essential that the tank interior and surfaces of conductors
and insulators be kept free from carbon, fibres and moisture as contamination will
lower the electric strength of the oil. Prior to filling switchgear tanks with oil, it is
good practice first to rinse the interior of the tank and the immersed parts with clean
oil.
There should be as little aeration of the oil as possible during the filling of the tank,
and a good practice is to fill from the bottom of the tank. A standing time should be
allowed after the tank is filled before commissioning the equipment. Hot oil should
not be used to fill switchgear because of possible damage due to thermal stresses and
risk of condensation of moisture on cooling.
Should it be desired to dry out insulation the oil in the chamber should be circulated
and heated to gradually bring it up to the required temperature.
7.3.1.9 Tank and tank linings
The following recommendations apply:
(a) Tank linings should be inspected for evidence of burning or other damage, paying
special attention to the edges for signs of separation of the laminae, which often
indicates the presence of moisture. If moisture is suspected a sample of the lining
should be immersed in oil heated to approximately 105°C. The presence of moisture
will be indicated by frothing. Damp or damaged linings should be reconditioned or
renewed as necessary.
They should not be refitted until the tank has been thoroughly cleaned and dried.
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(b) Gaskets should be inspected and renewed where necessary.

(c) Special care should be taken to avoid damage to interpole barriers when replacing
tanks, since this could obstruct the opening of the circuit-breaker.
(d) All tank bolts shall be properly tightened in the correct sequence when replacing the
tank.
7.3.1.10 Tank lifting mechanism
Where the tank lifting mechanism is integral with the switchgear, the rope (where fitted)
and operating mechanism should be inspected for wear, corrosion and freedom of moving
parts. This inspection should be carried out before attempting to lower the tank.
Lifting mechanisms should be lubricated sparingly and hydraulic systems topped up as
necessary.

7.4 POST-FAULT MAINTENANCE

7.4.1 Isolation of withdrawable metal-clad switchgear
The isolation of withdrawable metal-clad switchgear should be delayed for at least 10 min
after operation on fault to allow for the dispersal of any ignitable gases.
7.4.2 Insulating oil
If the oil is badly discoloured or shows evidence of carbon particles in suspension, it may
require changing in accordance with the procedure referred to in Clause 7.3.2.8.
7.4.3 Joints and seals
All joints and seals including cemented joints should be inspected for tightness and
particular attention should be paid to tank gaskets where these are fitted.

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 AS 2467—2008 38

7.4.4 General mechanical inspection

A general inspection for mechanical damage or distortion of the general structure and
mechanism, both internal and external to the tank, should be made. The switchgear should
be closed and tripped. (See also Clause 7.2(c).)

7.5 SUMMARY OF MAINTENANCE OPERATIONS

The maintenance operations recommended for oil switchgear are summarized in Table 7.1.
A reference to the clause number in column 2, 3, 4 or 5 indicates that this type of
maintenance operation is appropriate.
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 39 AS 2467—2008

TABLE 7.1
MAINTENANCE OPERATIONS FOR OIL SWITCHGEAR*
1 2 3 4 5
Routine maintenance
Pre-maintenance Post-fault
Maintenance operation Examination
requirements Inspection maintenance
and overhaul
Safety of personnel 6.1.1
Equipment to be rendered inoperative 6.1.2
Precautions for oil switchgear 7.2
Diagnostic testing 6.3 6.3
Operational check 6.4 6.4 6.4
General inspection 6.5.1.1 6.5.1.1
Cleaning 7.3.1.1 6.6
Insulation 7.3.1.2 7.3.1.2
Enclosures 6.5.2.4 6.5.2.4
Contacts 6.5.2.5 6.6
Arc-control devices 7.3.1.3 6.6
Isolating contacts 6.5.2.9
Venting and gas seals 7.3.1.4 7.3.1.4 7.4
Mechanisms 7.3.1.5 7.4.4
Auxiliary switches 6.5.2.8
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Indicating devices and interlocks 6.5.2.8

Overload devices and protective relays Section 13 Section 13
Instrument and protective transformers Sections 12
and 13
Control relays or contactors 6.5.2.12
Insulating oil 7.3.1.8 7.4.2
Tank and tank linings 7.3.1.10 7.3.1.9 7.4.4
Tank lifting mechanism 7.3.1.10
Connections 6.5.2.13
Secondary wiring and fuses 6.5.2.14
Heaters 6.5.2.15
Isolators and earthing switches 6.5.2.16 6.5.2.16
Shutters 6.5.2.17
Switchgear spouts 6.5.2.18 6.5.2.18
Busbars and busbar chambers 6.5.2.19
Weather shields 6.5.2.20
High-voltage fuse connections and 6.8 6.8
associated linkage
Final verification 6.5.2.21 6.5.2.21 6.5.2.21
Auxiliary equipment Section 12 Section 12
* The numbers quoted in the columns refer to the appropriate clause number herein.

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 AS 2467—2008 40

SE C T I ON 8 MA I N T E N A N CE O F A I R- B L A ST
C I R C U I T - B R E A K E R SW I T CH G E A R

8.1 APPLICATION OF SECTION

Section 6 applies to the maintenance of air-blast circuit-breaker switchgear with the
additions and modifications given in Clauses 8.2 to 8.4.
NOTE: See Clause 8.5 for a summary of recommended maintenance operations.

8.2 PRE-MAINTENANCE REQUIREMENTS AND PRECAUTIONS

8.2.1 Reduction in air pressure
In some designs of circuit-breaker the air pressure in the air-conditioned sections will not
be reduced to atmospheric pressure by the isolation and drainage of the air receiver. In
these cases the manufacturer’s maintenance and operational instructions on the operation of
air conditioning during maintenance should be carefully followed.
8.2.2 Adjacent unsilenced circuit-breakers
Where work is being carried out with adjacent unsilenced circuit-breakers in service,
adequate precautions should be taken to protect personnel from the effects of noise caused
by these circuit-breakers should they operate, e.g. by the use of hearing protection devices
(see AS/NZS 1270).
8.2.3 Avoidance of hydraulic tests on air receivers
Unless required by the relevant statutory authority, hydraulic tests during periodic
inspections should be avoided as the introduction of any liquid into air-blast circuit-
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breakers can have a deleterious effect.

NOTE: Statutory authorities require air receivers (pressure vessels) to be inspected, tested and
certified periodically and it is often convenient to schedule maintenance to coincide with these
inspections.

8.3 ROUTINE MAINTENANCE

Clause 6.5 applies with the following additions and modifications.
8.3.1 Examination and overhaul
8.3.1.1 Cleaning
The interrupter chambers of fully pressurized circuit-breakers should be kept particularly
clean. An industrial vacuum cleaner fitted with a non-metallic nozzle may prove to be
suitable for this cleaning operation.
8.3.1.2 Lubrication
After the cleaning of control valves in control units, ensure that components including ‘O’
rings are lightly lubricated in accordance with manufacturer’s instructions before
reassembly.
8.3.1.3 Air conditioning
It should be verified that the flow of conditioning air is correct and that it is dry. Where
both input and output flow meters are fitted these should indicate the same readings. Failure
to do this indicates leakage of air which should be traced.
Any filters and orifices, etc., should be inspected.

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 41 AS 2467—2008

8.3.1.4 Insulation
Internal insulation of air-blast circuit-breakers rarely becomes contaminated but at overhaul
the opportunity may be taken to clean and examine it for any defects.
8.3.1.5 Local control kiosks
Operation of any heaters should be verified and any anticondensation finishes inspected for
signs of deterioration.
It should be verified that any emergency opening release fitted in or on a local control kiosk
correctly trips the circuit-breaker.
8.3.1.6 Pressure gauges
The correct operation of pressure gauges should be verified.
The accuracy of pressure gauges should be verified.
8.3.1.7 Pressure switches, including contact gauges
Pressure switches, including contact gauges should be inspected as follows:
(a) Correct operation and sequence of operations should be verified (if appropriate).
(b) Operation at correct pressure should be verified.
8.3.1.8 Interpole linkages
The following recommendations apply:
(a) Interpole linkages usually have carefully fitted linkage pins, and minimum backlash
mechanisms. It is important that these features be examined and adjusted as required,
to ensure minimum spread of timing between poles. Any deterioration in this respect
will usually be indicated in the timing test.
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(b) The manufacturer’s instructions for the setting dimensions of the interpole linkages
should be verified, and all nuts and bolts should be tight and all pivot pins secure.
(c) It should be verified that all fixings are tight and all pivot pins are secure.
On circuit-breakers fitted with mechanical or pneumatic intertripping between poles,
the correct function should be verified by initiating operations (close and open) of
each pole in turn and ensuring that in each case the remaining two poles follow suit.
NOTE: Interpole linkages should not be altered unless essential adjustments are required.
8.3.1.9 Dashpots associated with interpole linkages
The following recommendations apply:
(a) Malfunction of dashpots associated with interpole linkages is usually only shown up
by an appropriate travel record during the timing test and unless such a record is
available and indicates satisfactory operation, the dashpots should be carefully
inspected.
(b) For oil type dashpots, it should be verified that the oil level is correct.
(c) For air type dashpots, it should be verified that bleed holes are not blocked and that
clearances are satisfactory.
8.3.1.10 Mechanisms
Clause 6.5.2.7 applies with the following additions:
(a) Main mechanism The main mechanism should be examined and the setting
dimensions verified. Malfunction will usually be revealed by diagnostic tests and
discrepancies in the setting dimensions.

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 AS 2467—2008 42

Linkages should be inspected for free movement and attention should be given to any
signs of catching on ‘passing’ links.
(b) Valve gear Valve gear should be examined for leakage, and correct operation should
be verified.
NOTE: As diagnostic testing will not always show up faults or potential faults on valve gear,
it is recommended that a sample of valves on a rotation basis be inspected, cleaned and
relubricated. Hard, insufficient or too much lubricant can affect the operation of valves and
lubricant cannot be expected to remain effective over long periods. Seals will deteriorate over
a long period of time, especially if exposed to the atmosphere and consideration should be
given to replacement of seals on a regular basis.
To facilitate the overhaul of valve gear, consideration should be given to replacing
components and overhauling the units in a workshop under controlled conditions.
(c) Dashpots Oil type dashpots should be inspected for the correct level and operation,
and, where fitted, air type dashpots should be inspected for correct operation.
(d) Maintenance operating device Where a maintenance operating device is fitted to a
circuit-breaker, the manufacturer’s instructions with respect to tripping and closing
should be closely followed.
8.3.1.11 Sequence isolator
The fixed and moving contacts of the sequence isolator should be examined for signs of
overheating or burning, and where necessary cleaned, refurbished or replaced. The contacts,
contact springs and connecting braids should be inspected for freedom of movement within
their housings.
Circuit-breakers mounted out of doors should be inspected for signs of corrosion or
contamination.
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Fixed and moving contacts should be lubricated sparingly, if required, with the
recommended lubricant. Caution should be taken with the use of lubricants in dusty
situations.
8.3.1.12 Pressure vessels, air receivers and pipe work
The internal and external surfaces of local air receivers, pressure vessels and pipe work
should be kept clean and any damage to or deterioration of the paint surface should be made
good to prevent corrosion taking place.
NOTE: Statutory authorities require air receivers, pressure vessels to be inspected, tested and
certified periodically. This should be programmed to coincide with routine overhauls.
Moisture should be bled from air pressure vessels and pipe work at regular intervals.
Under no circumstances should moisture be present in the local air receiver of an air blast
circuit-breaker.
Fusible plugs should be inspected and replaced, if appropriate.
Safety valves should be inspected for freedom of operation and particularly for correct re-
seating after operation.
8.3.1.13 Interrupters
The following recommendations apply:
(a) Interrupter components Interrupters usually comprise the fixed and moving main
contacts, the nozzle and the associated valve gear. In some cases, particularly with
fully pressurized types of circuit-breaker, the interrupter also houses the resistor.

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 43 AS 2467—2008

(b) Fixed and moving main contacts At a suitable interval and on a rotation basis one
interrupter per pole should be examined to establish the rate of burning and erosion of
the contacts and the general condition in order to assess the necessity for further
maintenance, etc., of the other interrupters. This work shall be carried out under
reasonably dry weather conditions and precautions taken to avoid the ingress of any
moisture or dirt into the compartment.
Any burning away from the arcing area should be noted and investigated as this will
indicate that the arc is not positioning correctly.
The recommendations given in Clause 6.5.2.5 for the routine maintenance of contacts
should be followed, as appropriate.
(c) Nozzle The nozzle should be examined for excessive wear or cracking of the
material and any signs of non-centralization of the arc. This can best be done by
comparison with a new nozzle and measurement. The profile as well as the size of the
nozzle is important and if the size of profile or clearance to the contacts appears to be
changed considerably, the manufacturer’s recommendations should be followed.
In general nozzles will not need changing unless an increase in diameter of 5% or
more has taken place. Minor irregularities in the nozzle surface may be removed with
a fine file.
(d) Insulation The insulation adjacent to the arcing area should be examined for any
signs of contamination and if necessary cleaned. Burning of this insulation will
indicate a misplaced arc and if burning is found it should be investigated.
(e) Oil-filled grading capacitors, resistors and bushings Any oil-filled grading
capacitors, resistors or bushings should be examined for signs of leakage and
remedial action taken as necessary. Resistance measurements of resistors should be
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taken and, where practicable, an oil sample taken for test. Consideration should be
given to testing of capacitors for dielectric dissipation factor.
(f) Air-insulated capacitors and resistors and foil type capacitors Air-insulated
capacitors and resistors and foil type capacitors incorporated within the pressure
containing tube rarely give trouble and provided that an inspection does not indicate
malfunction, no action is necessary. Resistors should be inspected for moisture and
resistance measurements taken.
(g) Valve gear and linkages Valve gear and linkages should be inspected for correct
operation, setting dimensions should be verified and a leakage test carried out.
NOTE: Valve gear and linkages should not be disturbed unless an inspection for leakage and
correct operation or diagnostic tests show this to be necessary. If it is necessary, the work
should be done in clean surroundings and the manufacturer’s instructions closely followed.
(h) Exhaust outlets and silencers Exhaust outlets and any silencers should be examined
for blockages by birds’ nests and similar and cleaned as necessary.
(i) Seals Particular attention should be paid to the inspection of seals and consideration
given to replacement on a regular basis.
8.3.1.14 Equipment enclosures
Where circuit-breakers are mounted in enclosures, the enclosures should be inspected for
any signs of damage from the effects of air blast, ingress of water, etc.
The correct operation of pressure-relief vents and any heaters should be verified and any
anti-condensation finishes inspected for signs of deterioration.
Recommendations for insulation are given in Clause 8.3.2.4, for sequence isolators in
Clause 8.3.2.11 and for interlocks in Clause 6.5.2.8.

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 AS 2467—2008 44

8.3.1.15 Final verification

Before being returned to service following overhaul, the circuit-breaker should be subjected
to an operational check to ensure correct operation under close, open and close/open
conditions as recommended under diagnostic testing (see Clause 11.2.2) and the results
compared with the manufacturer’s recommendations and recorded for future comparison.
Also, where appropriate an insulation resistance test should be carried out (see Section 14).

8.4 POST-FAULT MAINTENANCE

The air-blast circuit-breaker should be capable of performing its rated operating duty at the
rated level before examination is necessary. In most cases this duty may be exceeded but
should only be so when the user, in consultation with the manufacturer, can show evidence
in support of this based on operating experience or test. The number of operations at
reduced fault may also be in excess of the rated number and the manufacturer should be
able to provide information on the permissible number. However, following fault operation
it is good practice to inspect a circuit-breaker at the earliest convenient opportunity.
After the permissible number of fault operations at a given level items (a) to (f) below
should be examined and, depending on the results of the examination or the manufacturer’s
recommendation, overhauled:
(a) Insulation, see Clause 8.3.2.4.
(b) Local control kiosk, see Clause 8.3.2.5.
(c) Sequence isolator, see Clause 8.3.2.11.
(d) Interrupters, see Clause 8.3.2.13.
(e) Enclosures, see Clause 8.3.2.14.
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(f) Overload devices and protective relays, see Section 13.

After examination and any overhaul, the circuit-breaker should be subjected to an
operational check (see Clause 8.3.2.15), and to any other relevant diagnostic tests.

8.5 SUMMARY OF MAINTENANCE OPERATIONS

The maintenance operations recommended for air-blast circuit-breaker switchgear are
summarized in Table 8.1. A reference to the clause number in column 2, 3, 4 or 5 indicates
that this type of maintenance operation is appropriate.

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 45 AS 2467—2008

TABLE 8.1
MAINTENANCE OPERATIONS FOR AIR BLAST CIRCUIT-BREAKER
SWITCHGEAR*
1 2 3 4 5
Routine maintenance
Pre-maintenance Post-fault
Maintenance operation Examination
requirements Inspection maintenance
and overhaul
Safety of personnel 6.1.1
Equipment to be rendered inoperative 6.1.2
Reduction in air pressure 8.2.1
Adjacent unsilenced circuit-breakers 8.2.2
Avoidance of hydraulic tests on air receivers 8.2.3
Diagnostic testing 6.3 6.3
Operation check 6.4 6.4 6.4
General inspection 6.5.1.1 6.5.1.1
Cleaning 8.3.1.1 8.4
Lubrication 8.3.1.2
Air conditioning 8.3.1.3 8.3.1.3
Insulation 8.3.1.4 8.3.1.4 8.4
Local control kiosk 8.3.1.5 8.3.1.5 8.4
Pressure gauges 8.3.1.6
Pressure switches 8.3.1.7
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Connections 6.5.2.13
Secondary wiring and fuses 6.5.2.14
Interpole linkages 8.3.1.8
Dashpots associated with interpole linkages 8.3.1.9
Mechanism 8.3.1.10
Auxiliary switches 6.5.2.8
Indicating devices and interlocks 6.5.2.8
Sequence isolator 8.3.1.11 8.4
Pressure vessels, air receivers and pipe work 8.3.1.12
Interrupters 8.3.1.13 8.4
Isolators and earthing switches 6.5.2.16
Enclosures 8.3.1.14 8.3.1.14 8.3.1.14
Overload devices and protective relays Section 13 Section 13
Instruments and protective transformers Sections 12
and 13
Control relays or contactors 8.3.1.15 6.5.2.12
Final verification Section 12 8.3.1.15 8.3.1.15
Auxiliary equipment Section 12
* The numbers quoted in the columns refer to the appropriate clause number herein.

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 AS 2467—2008 46

SECT I O N 9 MA I N T E N A N CE O F V A CU U M
C I R C U I T - B R E A K E R SW I T CH G E A R

9.1 APPLICATION OF SECTION

Section 6 applies to the maintenance of vacuum circuit-breaker switchgear with the
additions and modifications given in Clauses 9.2 to 9.5.
NOTE: See Clause 9.6 for a summary of recommended maintenance operations.

9.2 GENERAL
Because of the sealed nature of the vacuum interrupter itself, it is not possible to carry out
any preventive or corrective maintenance on it. Certain tests can however be carried out to
obtain information on the condition of the interrupter, and correct maintenance of the
associated mechanism and components will ensure that the life of the interrupter is not
unduly affected by external factors.

9.3 FREQUENCY OF MAINTENANCE

Clause 6.2 applies with the following addition.
9.3.1 Determination of frequency of maintenance
When determining the frequency of maintenance for vacuum circuit-breaker switchgear, the
results of comprehensive diagnostic testing (see Clause 6.3), should be considered together
with a record of the number of operations and current levels interrupted.
In addition, operational checks should be performed at regular internals irrespective of
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service history.
NOTE: Vacuum interrupters can perform many operations before renewal becomes necessary.
The interval which can be allowed between consecutive overhauls of vacuum circuit-breaker
switchgear will depend upon the operating conditions of the circuits controlled and the history
and performance of individual designs of equipment.

9.4 ROUTINE MAINTENANCE

Clause 6.5 applies with the following additions and modifications.
9.4.1 Examination and overhaul
9.4.1.1 Opening device (trip)
Immediately prior to the maintenance work commencing, the circuit-breaker should be
opened by means of the electrically operated opening release coils, if fitted, or by the
manual operation of the trip plunger.
When maintenance opening or closing devices are in use, the manufacturer’s advice on the
operation of the circuit-breaker should be closely followed.
NOTE: Care should be taken to ensure that all stored energy devices are discharged or rendered
inoperative.
9.4.1.2 Equipment enclosures
The correct operation of any heaters should be verified and any anticondensation finishes
inspected for signs of deterioration.

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 47 AS 2467—2008

9.4.1.3 Mechanisms
Clause 6.5.2.7 applies with the following additions:
(a) Examination and testing The main mechanism should be examined and the setting
dimensions verified. Malfunction will usually be revealed by diagnostic tests and
discrepancies in the setting dimensions.
Linkages should be inspected for free movement and attention should be given to any
signs of catching on ‘passing’ links.
(b) Correct damping The correct damping of vacuum circuit-breakers should be verified
to eliminate bounce on closing and to ensure that bounce on opening is not excessive.
9.4.1.4 Vacuum interrupter (see Clause 9.2).
Contact erosion should be measured and the contact force verified. The contact force is
affected by the degree of vacuum in the interrupter and any drastic change in force will
suggest a complete loss of vacuum.
NOTE: To check contact force, extensive dismantling may be necessary. The manufacturer’s
recommendation should be noted.
The integrity of the vacuum can be verified by a high-voltage breakdown test. However, the
manufacturer should be consulted for suitable test voltage levels as precautions may be
necessary to ensure that the levels of possible emitted X-radiation during these tests are
within safe limits.
Where there is more than one interrupter per pole, the inter-interrupter operating
mechanism should be inspected for synchronized operation. This mechanism should not be
slack or allow bounce of the contacts on opening.
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9.5 POST-FAULT MAINTENANCE

Vacuum circuit-breaker switchgear should be inspected at the earliest convenient
opportunity following an operation on fault.
After the permissible number of fault operations at a given level, items (a) to (d) below
should be examined and depending on the results of the examination or the manufacturer’s
recommendations, overhauled:
(a) Insulation, see Clause 6.5.2.3.
(b) Isolating contacts, see Clause 6.5.2.9.
(c) Vacuum interrupter, see Clause 9.4.2.4.
(d) Isolators and earthing switches, see Clause 6.5.2.16.
After examination and any overhaul the circuit-breaker should be subjected to an
operational check (see Clause 6.4), and to any other relevant diagnostic tests.

9.6 SUMMARY OF MAINTENANCE OPERATIONS

The maintenance operations recommended for vacuum circuit-breaker switchgear are
summarized in Table 9.1. A reference to the clause number in column 2, 3, 4 or 5 indicates
that this type of maintenance operation is appropriate.

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 AS 2467—2008 48

TABLE 9.1
MAINTENANCE OPERATIONS FOR VACUUM CIRCUIT-BREAKER
SWITCHGEAR*
1 2 3 4 5
Routine maintenance
Pre-maintenance Post-fault
Maintenance operation Examination
requirements Inspection maintenance
and overhaul
Safety of personnel 6.1.1
Equipment to be rendered inoperative 6.1.2
Diagnostic testing 6.3 6.3
Operational check 6.4 6.4 6.4
General inspection 6.5.1.1 6.5.1.1
Cleaning 6.5.2.2 6.5.2.2
Opening device (trip) 9.4.1.1 9.4.1.1 9.4.1.1
Insulation 6.5.2.3 6.5.2.3 9.5
Enclosures 9.4.1.2
Connections 6.5.2.13
Secondary wiring and fuses 6.5.2.14
Mechanisms 9.4.1.3
Auxiliary switches 6.5.2.8
Indicating devices and interlocks 6.5.2.8
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Isolating contacts 6.5.2.9

Shutters 6.5.2.17
Switchgear spouts 6.5.2.18 6.5.2.18
Vacuum interrupter 9.4.1.4 9.4.1.4
Isolators and earthing switches 6.5.2.16 6.5.2.16 9.5
Overload devices and protective relays Section 13 Section 13
Instrument and protective transformers Sections 12
and 13
Control relays or contactors 6.5.2.12
Busbars and busbar chamber 6.5.2.19
Final verification 6.5.2.21 6.5.2.21 6.5.2.21
Auxiliary equipment Section 12 Section 12
* The numbers quoted in the columns refer to the appropriate clause number herein.

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 49 AS 2467—2008

SE C T I O N 1 0 MA I N T E N A N CE O F SU L PH U R
H E X A F L U OR I D E C IRCU I T - B RE A K E R
S W I T CH G E A R

10.1 APPLICATION OF SECTION

Section 6 applies to the maintenance of sulphur hexafluoride circuit-breaker switchgear
with the additions and modifications given in Clauses 10.2 to 10.6.
NOTE: See Clause 10.7 for a summary of recommended maintenance procedures.

10.2 SPECIAL CONSIDERATIONS ARISING FROM THE USE OF SULPHUR

HEXAFLUORIDE
10.2.1 Properties of sulphur hexafluoride
Sulphur hexafluoride (SF6 ) in its pure state is a colourless, odourless, tasteless, non-toxic
gas which is heavier than air and has very good dielectric and arc-extinguishing properties.
It is used for both main insulation and arc-extinguishing in circuit-breakers at quite
moderate pressures.
10.2.2 SF6 circuit-breakers
In general there are two types of SF6 circuit-breaker:
(a) Puffer or single pressure type—where the moving contact is linked to a piston which
displaces gas and forces it through the nozzle.
(b) Dual pressure type—where gas is stored at high pressure and blasted to a lower
pressure through the nozzle, the low pressure gas then being returned to the high
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pressure storage via a compressor.

10.2.3 Statutory regulations
Attention is drawn to any statutory regulations which may apply to the use of pressure
vessels containing SF6.
10.2.4 Warnings to personnel
When operating instructions are carried out correctly, SF6 equipments are completely safe,
but it is necessary that all personnel entering a substation containing SF6 equipments should
be acquainted with the following:
(a) SF 6 is a very heavy gas, about five times as dense as air. This gives rise to a serious
potential hazard; equipment, trenches and similar enclosed spaces may remain full of
the gas, which, if pure, has no colour or odour which might warn personnel of this
fact. Therefore it is essential to note the following warning.
WARNING: ALTHOUGH UNCONTAMINATED SULPHUR HEXAFLUORIDE
(SF6) IS NON-TOXIC, IT WILL NOT SUPPORT LIFE, AND UNPROTECTED
PERSONNEL ENTERING AN SF6 -FILLED ENCLOSURE, TRENCH, ETC.,
WILL BE ASPHYXIATED. IT IS ESSENTIAL THAT PERSONNEL BE MADE
AWARE OF THIS DANGER AND THAT EQUIPMENT IS ADEQUATELY
VENTILATED IF IT IS TO BE ENTERED WITHOUT BREATHING
APPARATUS. IF THERE IS ANY DOUBT WHATSOEVER IT IS ESSENTIAL
TO DETERMINE THE PRESENCE AND CONCENTRATION OF SF6 GAS BY
THE USE OF AN SF6 GAS DETECTOR.

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 AS 2467—2008 50

(b) Although uncontaminated SF 6 gas is non-toxic, some of the gaseous impurities

produced by electrical breakdowns e.g. arcing in the gas, are toxic if inhaled in
sufficient quantity, and the solid fluoride powders, also produced by breakdown, may
produce skin irritation. However, present experience shows that if personnel are
exposed to significant amounts of breakdown products, definite warning indications
will very quickly appear, such as irritation of the nose, mouth and eyes. Also, the
presence of breakdown products is indicated by a pungent or unpleasant odour. These
warning signs will occur within seconds and well before any significant toxic effects
can take place. If a pungent or unpleasant odour appears, personnel should quickly
get into fresh air. If it is necessary to remain in such an atmosphere, self-contained
compressed air breathing apparatus or air-line breathing apparatus should be worn.
(c) Special filters, e.g. molecular sieves, are fitted in certain equipment to absorb gaseous
breakdown products. Before attempting to remove such filters the operator should be
familiar with the manufacturer’s instructions for doing this, together with his
instructions for the treatment and disposal of used filter material, cleaning the
container and recharging it with new material. On no account should untreated filter
material removed from the circuit-breaker after service be heated.
(d) On first opening up equipment for inspection of the interior, personnel should take
particular care to avoid exposure to possible breakdown products, and suitable
protective clothing should be worn. This would include suitable overalls, thin rubber
gloves, chemical-type box goggles and a respirator incorporating a dust filter and
activated charcoal. When any dust and breakdown products have been removed from
the interior of the apparatus the respirator and goggles can be taken off. Users should
lay down a code of practice covering these operations.

10.3 PRE-MAINTENANCE REQUIREMENTS AND PRECAUTIONS

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Clause 6.1 applies with the following additions.

10.3.1 Access to equipment in contact with SF6
Before work involving access to any part of the equipment which is, or has been, in contact
with the SF 6 or associated compounds is commenced, the circuit-breaker must be isolated
from all sources of supply of the gas by locking closed any gas inlet valves, the gas must be
removed and the circuit-breaker brought to atmospheric pressure. The interior must then be
cleaned of any dust or breakdown products taking cognizance of the precautions previously
mentioned.
The gas would normally be removed with gas servicing equipment. The cleaning would
normally be carried out with a vacuum cleaner fitted with a disposable bag and disposable
cloths or tissues. These materials should be treated before disposal strictly in accordance
with the manufacturer’s recommendations.
10.3.2 Maintenance opening or closing jacks
When maintenance opening or closing jacks are in use, the manufacturer’s advice on the
operation of the circuit-breaker should be closely followed.

10.4 FREQUENCY OF MAINTENANCE

Clause 6.2 applies with the following addition.
10.4.1 Factors to be considered for SF6 circuit-breakers
Factors to be considered should include the following:
(a) To determine the frequency of maintenance of SF 6 circuit-breakers, the results of
comprehensive diagnostic techniques (see Clause 6.3), should be considered together
with a record of the number of operations and values of current interrupted.

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 51 AS 2467—2008

(b) In addition, operational checks should be performed at regular intervals irrespective

of service history.
All SF6 circuit-breakers, whatever their class of duty, should be inspected at intervals
not exceeding 1 year in order to determine whether any further maintenance is
necessary.
(c) SF 6 circuit-breakers can operate many times before overhaul becomes necessary and
advantage should be taken of this fact to avoid unnecessarily opening the circuit-
breaker interior to atmosphere, since it is essential that the interior be kept absolutely
dry.
(d) The interval which can be allowed between overhauls will depend upon the operating
conditions of the circuits controlled and the history and performance of individual
designs of equipment.

10.5 ROUTINE MAINTENANCE

Clause 6.5 applies with the following additions and modifications.
10.5.1 Examination and overhaul
10.5.1.1 Opening device (trip)
Immediately prior to the maintenance work commencing, the circuit-breaker should be
opened by means of the electrically operated opening release coils, if fitted, or by the
manual operation of the trip plunger.
NOTE: Care should be taken to ensure that all stored energy devices are discharged or rendered
inoperative.
10.5.1.2 Gas system
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It should be verified that the gas system is operating at the required pressure and, on dual
pressure equipment, that the relationship between high pressure and low pressure is correct.
The pressure/temperature conditions should be recorded at regular intervals and checked
against the constant density characteristics.
The oil level in the compressor should be verified, if applicable, as should the pumping
time to raise pressure by a given amount. This latter information should be recorded.
Filters or desiccants should be replaced at periodic intervals and always after the gas system
has been opened to atmosphere. Under no circumstances should untreated filter or desiccant
material removed from the circuit-breaker after service be heated.
10.5.1.3 SF 6 gas
The SF 6 gas should be sampled and tested in accordance with the requirements of
IEC 60480.
Particular attention should be paid to the following:
(a) Condensation temperature The condensation temperature should be checked at
regular intervals. The required condensation temperature will depend on the location
of the circuit-breaker and the prevailing environmental conditions, and will usually be
specified by the manufacturer. However, in general it should not be above the
minimum expected ambient temperature.
In dual-pressure circuit-breakers this condensation temperature refers only to the low
pressure gas, provided that the high pressure gas is not used for insulation purposes.
Usually the high pressure gas is heated and the condensation temperature of the gas at
this pressure should be above the minimum operating temperature. When referred to
atmospheric pressure the condensation temperature of the high pressure gas shall be
equal to or lower than that of the low pressure gas.

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 AS 2467—2008 52

It is expected that the only condensable material of any significance will be water but
the tests recommended will reveal the presence of significant amounts of other
condensable materials.
If the condensation temperature of the gas is found to be above an acceptable level,
the gas shall be dried or replaced with dry gas. The cause of the defect should be
investigated and it may be necessary to dry out the circuit-breaker before introducing
fresh gas.
After the circuit-breaker is refilled, the condensation temperature shall be checked at
a more regular intervals until an acceptable and stable level is reached.
(b) Oxygen content The oxygen content should normally be kept below 1% by volume,
but the circuit-breaker manufacturer will give recommended figures for particular
types of circuit-breaker. The oxygen content should only need to be checked
immediately after filling a circuit-breaker to ensure that no air has been left inside.
Previously used gas should be tested before the circuit-breaker is filled.
If the oxygen level is too high, the excess oxygen shall be removed. If the gas is in, or
can be put into, a storage tank at a pressure at which liquefaction has taken place,
excess oxygen can usually be removed by ‘dumping’ some of the gas above the liquid
rapidly to atmosphere for a few seconds. The ‘dumping’ process can be repeated a
number of times until the desired oxygen level is achieved.
(c) Acidity and hydrolysable fluoride content of gas The acidity and hydrolysable
fluoride content of the gas should be tested at suitable intervals to ensure that the
manufacturer’s maximum recommended level for the impurities has not been
exceeded. Previously used gas should be tested before the circuit-breaker is filled.
10.5.1.4 Insulation
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Clause 6.5.2.3 applies with the following addition:

Bushings and insulators should be examined for gas leaks.
10.5.1.5 Local control kiosks
Operation of any heaters should be verified and any anti-condensation finishes inspected for
signs of deterioration.
It should be verified that any emergency opening release fitted in or on a local control kiosk
correctly trips the circuit-breaker.
10.5.1.6 Pressure gauges
The correct operation of pressure gauges should be verified.
The accuracy of pressure gauges should be verified.
10.5.1.7 Pressure switches, including contact gauges
Pressure switches, including contact gauges should be inspected as follows:
(a) Correct operation and sequence of operations (if appropriate), should be verified.
(b) Operation at correct pressure should be verified.
NOTE: In some cases the pressure switches on SF 6 circuit-breakers are temperature
compensated so that their characteristics follow a constant density curve. Where relevant, the
switch should be calibrated to this curve.
10.5.1.8 SF 6 gas heaters
On ‘dual-pressure’ circuit-breakers, the high pressure gas is usually heated to ensure that
liquefaction does not take place. It is essential that the correct operation of these heaters be
verified regularly.

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 53 AS 2467—2008

It should be verified that the thermostats controlling the heaters operate within the required
limits.
10.5.1.9 Interpole linkages
The following recommendations apply:
(a) Interpole linkages usually have carefully fitted linkage pins, and minimum backlash
mechanisms. It is important that these features be examined and adjusted as required,
to ensure minimum spread of timing between poles. Any deterioration in this respect
will usually be indicated in the timing test.
(b) The manufacturer’s instructions for the setting dimensions of the interpole linkages
should be verified, and all nuts and bolts should be tight and all pivot pins secure.
(c) It should be verified that all fixings are tight and all pivot pins are secure.
NOTE: Interpole linkages should not be altered unless essential adjustments are required.
10.5.1.10 Dashpots associated with interpole linkages
The following recommendations apply to dashpots associated with interpole linkages:
(a) Malfunction of dashpots associated with interpole linkages is usually only shown up
by an appropriate travel record during the timing test and unless such a record is
available and indicates satisfactory operation, the dashpots should be carefully
inspected.
(b) For oil type dashpots, it should be verified that the oil level is correct.
(c) For air type dashpots, it should be verified that bleed holes are not blocked and that
clearances are satisfactory.
(d) On circuit-breakers fitted with mechanical or pneumatic intertripping between poles,
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the correct function should be verified by initiating operations (close and open) of
each pole in turn and ensuring that in each case the remaining two poles follow suit.
10.5.1.11 Mechanisms
Clause 6.5.2.7 applies with the following additions:
(a) Main mechanism The main mechanism should be examined and the setting
dimensions verified. Malfunction will usually be revealed by diagnostic tests and
discrepancies in the setting dimensions.
Linkages should be inspected for free movement and attention should be given to any
signs of catching on ‘passing’ links.
(b) Valve gear Valve gear should be examined for leakage and correct operation should
be verified.
NOTE: Valve gear in general should not be disturbed unless an examination for leakage and
correct operation or diagnostic tests show this to be necessary. If it is necessary, the work
should be done in clean surroundings and the manufacturer’s instructions closely followed.
(c) Dashpots Oil type dashpots should be inspected for the correct level and operation,
and, where fitted, air type dashpots should be inspected for correct operation.
(d) Maintenance operating device Where a maintenance operating device is fitted to a
circuit-breaker, the manufacturer’s instructions with respect to tripping and closing
should be closely followed.

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 AS 2467—2008 54

10.5.1.12 Interrupters
The following recommendations apply:
(a) Interrupter components Interrupters usually comprise the fixed and moving main
contacts, the nozzle and the associated valve gear. In some cases, particularly with
fully pressurized types of circuit-breaker, the interrupter also houses the resistor.
The nozzle is usually made from PTFE.
(b) Fixed and moving main contacts At a suitable interval, one interrupter per pole
should be examined to establish the rate of burning and erosion of the contacts and
the general condition in order to assess the necessity for further maintenance, etc., of
the other interrupters. This work should be carried out under reasonably dry weather
conditions and precautions taken to avoid the ingress of any moisture or dirt into the
compartment.
Any burning away from the arcing area should be noted and investigated as this will
indicate that the arc is not positioned correctly.
The recommendations given in Clause 6.5.2.5 for the routine maintenance of contacts
should be followed, as appropriate.
(c) Nozzle The nozzle should be examined for excessive burning or erosion and this can
be done by comparison with a new nozzle. In general the dimensions and profile of
the nozzle are not as critical as on an air-blast circuit-breaker (see Clause 8.3.2.13(c))
and therefore a greater amount of erosion can be tolerated before replacement
becomes necessary. However, the manufacturer’s recommendations in this respect
should be carefully followed.
(d) Insulation The insulation adjacent to the arcing area should be examined for any
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signs of contamination and if necessary cleaned. Burning of this insulation will

indicate a misplaced arc and if burning is found it should be investigated.
(e) Valve gear and linkages Valve gear and linkages should be inspected for correct
operation, setting dimensions should be verified and a leakage test carried out.
NOTE: Valve gear and linkages should not be disturbed unless an inspection for leakage and
correct operations or diagnostic tests show this to be necessary. If it is necessary the work
should be done in clean surroundings and the manufacturer’s instructions closely followed.
10.5.1.13 Local air receivers and pressure vessels
The internal and external surfaces of local air receivers and SF6 pressure vessels should be
kept clean and any damage to or deterioration of the paint surface should be made good
with a suitable paint to prevent corrosion taking place.
NOTE: Statutory authorities require air receivers and pressure vessels to be inspected, tested and
certified periodically. Similar requirements may also apply to SF 6 pressure vessels.
Fusible plugs should be inspected and replaced, if appropriate.
Safety valves should be inspected for freedom of operation and particularly for correct re-
seating after operation.
10.5.1.14 Filters and desiccants
Filters and/or desiccants are normally installed in SF6 circuit-breakers to filter out or absorb
some of the breakdown products. As a last operation prior to closing up the chambers of the
circuit-breaker the filters or desiccants should be replaced. Under no circumstances should
untreated filter or desiccant material which has been removed from the circuit-breakers
after service, be heated.

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 55 AS 2467—2008

10.5.1.15 Final verification

Before being returned to service following overhaul, the circuit-breaker should be subjected
to an operational check to ensure correct operation under close, open and close/open
conditions as recommended under diagnostic testing (see Clause 11.2.2) and the results
compared with the manufacturer’s recommendations and recorded for future comparison.
Also, where appropriate, an insulation resistance test should be carried out (see Section 14).

10.6 POST-FAULT MAINTENANCE

The SF 6 circuit-breaker should be capable of performing its rated operating duty at the rated
level before examination or minor overhaul is necessary. In most cases this duty may be
exceeded but only when the user, in consultation with the manufacturer, can show evidence
in support of this based on operating experience or test. The number of operations at
reduced fault may also be in excess of the rated number and the manufacturer should be
able to provide information on the permissible number. However, following fault operation
it is good practice to inspect a circuit-breaker at the earliest convenient opportunity.
After the permissible number of fault operations at a given level, items (a) and (b) below
should be examined and depending on the results of the examination or the manufacturer’s
recommendation, overhauled:
(a) Insulation (see Clause 10.5.2.4).
(b) Interrupters (see Clause 10.5.2.12).
After examination and any overhaul, the circuit-breaker should be subjected to an
operational check (see Clause 10.5.2.15), and to any other relevant diagnostic tests.

10.7 SUMMARY OF MAINTENANCE OPERATIONS

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The maintenance operations recommended for SF6 circuit-breaker switchgear are

summarized in Table 10.1. A reference to the clause number in column 2, 3, 4 or 5 indicates
that this type of maintenance operation is appropriate.

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 AS 2467—2008 56

TABLE 10.1
MAINTENANCE OPERATIONS FOR SULPHUR HEXAFLUORIDE CIRCUIT-
BREAKER SWITCHGEAR*
1 2 3 4 5
Routine maintenance
Pre-maintenance Post-fault
Maintenance operation Examination
requirements Inspection maintenance
and overhaul
Safety of personnel 10.2 and 10.3
Equipment to be rendered inoperative 6.1.2 and 10.5.1.1
Diagnostic testing 6.3 6.3
Operational check 6.4 6.4
General inspection 6.5.1.1 6.5.1.1
Cleaning 6.5.2.2 6.6
Opening device (trip) 10.5.1.1 10.5.1.1
Enclosures 6.5.2.4
Gas system 10.5.1.2 10.5.1.2
SF 6 gas 10.5.1.3 10.5.1.3
Insulation 10.5.1.4 10.5.1.4 10.6
Local control kiosks 10.5.1.5 10.5.1.5
Pressure gauges 10.5.1.6
Pressure switches 10.5.1.7
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Connections 6.5.2.13
Secondary wiring and fuses 6.5.2.14
SF 6 gas heaters 10.5.1.8 10.5.1.8
Interpole linkages 10.5.1.9
Dashpots associated with interpole linkages 10.5.1.10
Mechanisms 10.5.1.11
Auxiliary switches 6.5.2.8
Indicating devices and interlocks 6.5.2.8
Interrupters 10.5.1.12 10.6
Isolators and earthing switches 6.5.2.16 6.5.2.16
Local air receivers and pressure vessels 10.5.1.13
Filters and desiccants 10.5.1.14
Overload devices and protective relays Section 13 Section 13
Instrument and protective transformers Sections 12
and 13
Control relays or contactors 6.5.2.12
Busbar and busbar chambers 6.5.2.19
Final verification 10.5.1.15 10.5.1.15 10.5.1.15
Auxiliary equipment Section 12 Section 12 10.5.1.15
* The numbers quoted in the columns refer to the appropriate clause number herein.

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 57 AS 2467—2008

SECT ION 11 D I AGNOS T IC TEST I N G

11.1 GENERAL
Where practicable, the maximum use should be made of diagnostic testing techniques to
indicate the condition of the equipment and to prolong the intervals between dismantling
and, for sulphur hexafluoride circuit-breaker switchgear, the opening of the interior of gas
compartments to atmosphere.
It is important to keep records of all diagnostic tests so that comparisons can be made and
trends estimated; but lists alone, which indicate only that measurements have been taken,
are not sufficient.
By comparison with previous similar tests, diagnostic tests will provide guidance to
possible deterioration and may indicate a need to vary maintenance intervals under
particular service conditions.
Clauses 11.2 to 11.4 briefly describe commonly used diagnostic tests and Table 11.2
indicates the applicability of the tests to the various types of switchgear.

11.2 DIAGNOSTIC TESTS FOR CORRECT OPERATION

11.2.1 Time-travel test
This test provides a record of moving contact travel with respect to time during opening and
closing operations. Generally a stylus is attached via linkages either to the moving contact
itself or to a suitable point on the operating mechanism linkage and a trace is obtained on a
chart attached to a rotating drum.
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By suitable calculations, the speed of the moving contact, and opening and closing times
can be obtained. The performance of other components, such as contact buffers can be
assessed.
11.2.2 Timing test
Timing tests are generally carried out using multi-channel apparatus. Sequence tests, e.g.
close, open and close/open operations, should be carried out and the time from initiation,
i.e. energization of coils, to the operation of the contact(s) recorded.
Timing of auxiliary switches and resistor switch contacts, where fitted, should also be
considered.
The timing tests should be arranged so that the number of operations given to the circuit-
breaker is kept to a minimum, consistent with the number of timing channels available and
the information required from a particular test. Comparisons between poles and for multi-
head circuit-breakers between individual breaks on the one pole are important. Tolerances,
where specified by the manufacturer, should be strictly adhered to.
Sequence timing tests should be carried out at 100% of the rated voltage of operating coils
and at 100% of the maximum operating pressure in air/gas operated circuit-breakers or at
the specified minimum operating voltage and/or lockout pressures.
11.2.3 Operating voltages
The measurement of minimum operating voltages of both closing and tripping functions or
operations at specified percentages of normal operating voltages, as given in the relevant
equipment standard, is recommended. Sluggish operation at reduced voltage may give an
early indication of mechanism deterioration.
These tests should be carried out in conjunction with time-travel or timing tests.

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 AS 2467—2008 58

11.2.4 Operation of pressure switches

For pneumatically operated circuit-breakers, tests should be carried out to determine the
correct operation of pressure switches.
11.2.5 Compressed air and gas systems
Information on the general condition of compressed air and gas systems can be obtained
from a study of the number of compressor starts and the hours run compared with circuit-
breaker operations and a knowledge of the pressure and temperature conditions in each
system. Pressure changes per operation, times to restore pressure and similar test results
should be recorded.
Air leakage tests should be carried out on a complete circuit-breaker by isolating it from the
source of supply and recording the pressure drop from a given time. Unless the leaks are
great (in which case they may be audible) the time allowed should be as long as possible so
that more accurate figures can be obtained. Allowance should be made for any conditioning
air and any ambient temperature variations occurring during the test.
Special solutions are available (soap solution is very satisfactory) for detecting inaudible
leaks and tracing the exact location of audible leaks.
11.2.6 Hydraulic systems
Information on the general condition of hydraulic systems can be obtained from a study of
the number of pump starts and the hours run compared with circuit-breaker operations and a
knowledge of pressure and temperature conditions in the system. Pressure changes per
operation, times to restore pressure and similar test results should be recorded.

11.3 DIAGNOSTIC TESTS FOR CONTACTS AND CONNECTIONS

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11.3.1 Resistance tests

Millivolt drop or resistance tests should be carried out, where possible, across each
complete pole and across individual series connected components to detect any
deterioration in contacts and connections.
These values can be compared with measurements taken during the manufacturer’s
temperature-rise tests.
11.3.2 Infrared detection
The temperatures of exposed contacts and connections can be determined by instruments
using infrared detection techniques.
These instruments are particularly useful for scanning contacts and connections in outdoor
situations, without de-energization, to detect excessive temperature rises due to arcing or
deterioration of the contacts and connections, and if possible should be carried out with
high levels of current.

11.4 DIAGNOSTIC TESTS FOR INSULATION

11.4.1 Insulation tests—General
Insulation tests can give useful information provided that they are carefully carried out. It
should be noted that non-organic insulation is not generally subject to degradation but in
some cases the internal surfaces may become contaminated. The tests are particularly useful
for organic insulation.
Partial discharge measurements provide valuable information but shall be carried out under
test laboratory conditions. For this reason such tests are not regarded as a normal diagnostic
test.

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 59 AS 2467—2008

Where these tests are carried out it is particularly important to keep records so that changes
and trends can be established.
Reference should also be made to Section 14.
11.4.2 Insulation resistance test
11.4.2.1 Determination
The quality of the insulation can be determined by measuring the resistance between
current-carrying parts and earth by use of suitable test equipment.
11.4.2.2 Applied voltages for insulation resistance tests
The voltage which should be applied to primary insulation when making resistance tests
varies according to the voltage rating of the switchgear. Table 11.1 gives a guide to test
voltages.
The insulation resistance of small wiring and ancillary components should be tested at a
voltage not exceeding 500 V d.c.
NOTE: Certain types of equipment, e.g. equipment incorporating semiconductors, may not be
suitable for this test and should therefore be isolated.
11.4.3 Measurement of dielectric dissipation factor
The regular measurement of the dielectric dissipation factor (tangent delta) and capacitance
of electrostatically graded (condensor) bushings is recommended. The measurements should
be carried out in accordance with AS 1265.

TABLE 11.1
APPLIED VOLTAGES FOR INSULATION RESISTANCE TEST
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3-phase voltage rating of primary Test voltages recommended for

insulation of switchgear insulation resistance test (to earth
and between phases)
kV kV (d.c.)
Up to 1 1
Above 1 to 3.6 2
Above 3.6 to 12 5
Above 12 10

11.4.4 Gas leakage test (SF6 circuit-breaker switchgear)

The verification of gas pressure, with the reading of the gas pressure and temperature,
should indicate any gas leaks. Special solutions are available (soap solution is very
satisfactory) for detecting inaudible leaks and tracing the exact location of audible leaks.
Gas leaks can also be detected by suitable commercial leak detection equipment. In general
because of its extreme sensitivity this equipment is not suitable for finding the exact
locations of large leaks.
11.4.5 Air quality (Air-blast circuit-breaker switchgear)
The condensation temperature (dew point) of the operational compressed air should be
measured. The required condensation temperature will depend on the environmental
conditions in which the circuit-breaker is installed, but at the specified air pressure it should
not be greater than the minimum expected ambient temperature.
The sample pipes used should preferably be of stainless steel, or alternatively polyethylene
or PTFE. Sample pipes of nylon, PVC or rubber should not be used.

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 AS 2467—2008 60

TABLE 11.2
APPLICABILITY OF DIAGNOSTIC TESTS*
1 2 3 4 5 6 7
Air circuit-
Sulphur
Switchgear up breakers intended Air-blast Vacuum
Oil hexafluoride
to for operation at circuit- circuit-
Test switch- circuit-
1000 V a.c.and voltage above breaker breaker
gear breaker
1200 V d.c. 1000 V a.c. and switchgear switchgear
switchgear
1200 V d.c.
Operation
Time-travel test 11.2.1 11.2.1 11.2.1
Timing test 11.2.2 11.2.2 11.2.2
Operating voltages 11.2.3 11.2.3 11.2.3 11.2.3 11.2.3
Operating (11.2.4—as applicable)
pressures
Compressors/syste (11.2.5—as applicable)
m performance
Hydraulic system (11.2.6—as applicable)
performance
Contacts and
connections
Resistance tests 11.3.1 11.3.1 11.3.1 11.3.1 11.3.1 11.3.1
Infrared detection (11.3.2—as applicable)
Insulation
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Insulation 11.4.2 11.4.2 11.4.2 11.4.2 11.4.2 11.4.2

resistance
Dielectric (11.4.3—as applicable)
dissipation factor
Gas leakage 11.4.4
Air quality 11.4.5
* A reference to the clause number in columns 2 to 7 indicates that this test is appropriate.

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 61 AS 2467—2008

SECT ION 12 MA I NTEN ANCE OF A U X I L I ARY

I T E M S

12.1 EQUIPMENT FOR TRIPPING AND CLOSING CURRENT SUPPLY

It is important that the equipment for the supply of current for tripping and closing gear be
kept in good condition.

12.2 GENERAL PRECAUTIONS FOR BATTERY INSTALLATIONS

12.2.1 Precautions to be taken in battery charging areas
As hydrogen is produced during battery charging, smoking or the use of naked flames
should be prohibited at all times in the immediate vicinity of battery installations.
Precautions should also be taken to avoid causing sparks near the battery.
Adequate notices or warning signs should be displayed in areas where hydrogen is
produced.
12.2.2 Handling electrolyte
When electrolyte is handled, protective clothing should be worn and special care should be
taken to avoid spillage on to the skin.
Where chemical burns are sustained, the affected area should be washed immediately with a
copious supply of clean water and medical attention should be sought (see Clause 2.3).
12.2.3 Avoid mixing or contamination of electrolytes
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Separate battery utensils should be kept for lead-acid type or alkaline type batteries since
any mixture with or contamination by an incorrect electrolyte may damage a battery.

12.3 SECONDARY CELL BATTERIES

12.3.1 General
12.3.1.1 Application
Secondary cell batteries may be used for supplying protection, control and instrument
circuits and may also supply indicator lights and provide emergency lighting.
12.3.1.2 Battery condition
Secondary cell batteries should be kept in a satisfactory state of charge and the condition
and level of electrolyte should be regularly examined.
12.3.1.3 Indicator of battery condition
Where batteries are used solely for tripping, they should be provided with an instrument
having a loading resistor test switch so that a simple switching operation can reveal the
state of the battery. The dial should include a danger mark to indicate the critical condition.
12.3.1.4 Verification of correct operation charging equipment
The correct operation of any continuously operating trickle-charging or constant voltage
charging equipment should be regularly verified.
12.3.1.5 Periodic charge and discharge
Where periodic charge and discharge take place, particular attention will be needed to guard
against unusual drainage of the battery or overload of the charger.

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12.3.1.6 Avoidance of damage to electronic equipment during boost charging

Care should be taken during boost charging to ensure that the terminal voltage does not
cause damage to electronic equipment in the circuit. In this respect, it may be necessary to
disconnect such equipment, or alternatively to arrange for a circuit using diodes to suppress
voltage at the load while applying boost voltage to the cells.
12.3.2 Routine maintenance
The following maintenance should be carried out on a routine basis:
(a) Battery cells should, where practicable, be inspected for shedding of active material,
sedimentation and buckling of the plates.
(b) Measurement of cell voltage while under charge.
(c) Measurement of electrolyte specific gravity.
NOTE: For alkaline cells the specific gravity does not indicate the degree of charge.
(d) The electrolyte level should be inspected and where necessary topped up accurately to
the correct level with distilled water.
(e) The terminal posts should be inspected for corrosion and tightness of the connections
and, after cleaning as necessary, lightly greased with petroleum jelly or other
corrosion inhibitor.
12.3.3 Electrolyte condition
12.3.3.1 General
In all cases the recommendations of the battery manufacturer for particular types of battery
installation should be closely followed.
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12.3.3.2 Stratification of the electrolyte

Experience has shown that under trickle-charge conditions, stratification of the electrolyte
can occur and it is recommended, particularly where batteries are used for closing, that at
intervals not greater than 2 years or following a significant degree of topping up, the battery
be charged at a high rate for a short period after topping up. Where trickle charging is
employed, the battery should be given a periodic charge discharge cycle or a boost charge.
12.3.3.3 Lead-acid batteries
For lead-acid batteries, special care should be taken to avoid unnecessary gassing charges
as this tends to cause scaling and shedding of active materials and buckling of the plates.
The life and reliability of a battery can be considerably reduced by incorrect rates and too
frequent boost charging.
12.3.3.4 Alkaline batteries
A discharge test is the only reliable method of checking the condition and capacity of
alkaline batteries. Such tests should be carried out every four to eight years. Several
discharge/charge cycles may be required to restore an optimum capacity.

12.4 PRIMARY CELL BATTERIES

Where batteries of primary cells are used in place of secondary cell batteries for tripping
circuits, they should be provided with a test instrument which will readily indicate their
condition. The maintenance of this type of cell is a simple inspection with replacement as
required.

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 63 AS 2467—2008

12.5 COMPRESSED AIR PLANT

Compressed air plant should be inspected as part of the regular substation inspection at
which time it is good practice where possible to carry out periodic start/stop tests.
These tests should consist of draining air receivers sufficiently to enable the automatic
operation of the plant to be checked.
NOTE: There are statutory obligations to inspect, test and certify air receivers (pressure vessels)
periodically at which time safety and reducing valves, if fitted, should also be inspected.
For guidance on the maintenance of compressed air plant, refer to the manufacturer’s
instructions. (See also Clauses 8.3.2.6, 8.3.2.7 and 8.3.2.12.)
The compressor manufacturer’s instructions regarding lubricating oil should be followed.

12.6 CURRENT TRANSFORMERS

12.6.1 Precautions
A current transformer should be proved dead, isolated and discharged to earth before it is
examined. Attention is drawn to the dangerous voltage which may result if the secondary
circuit of a current transformer is opened with the primary circuit on load. It is essential to
ensure that any connection removed for the purpose of carrying out these or other tests is
correctly replaced and securely tightened.
12.6.2 Current transformers which are accessible
Where current transformers are accessible, maintenance attention should consist of a
general inspection and verification that all main and secondary connections are tight. All
exposed insulation should be cleaned and examined thoroughly for any damage such as
cracks, tracking marks, and similar.
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12.6.3 Oil-filled current transformers

On oil-filled current transformers the oil level should be inspected and the required quantity
of the properly degassed correct oil added if necessary. At longer intervals the oil may
require testing in accordance with AS 1883. The gas pressure should be verified on current
transformers which use a nitrogen gas cushion to accommodate oil expansion.
12.6.4 SF6 insulated current transformers
Current transformers insulated by SF6 under pressure should be inspected to determine if
the correct gauge pressure is being maintained. If attention is necessary, the manufacturer’s
maintenance manual should be consulted. The dew point of the gas should be measured at
regular intervals in accordance with the requirements of IEC 60480.
12.6.5 Current transformers enclosed in metal-clad gear or otherwise inaccessible
Current transformers enclosed in metal-clad gear or otherwise inaccessible are usually safe
against mechanical damage and only electrical testing will determine whether they are in
good order. An insulation resistance and continuity test of the secondary winding should be
regarded as an essential minimum.

12.7 VOLTAGE TRANSFORMERS

12.7.1 Precautions
A voltage transformer should be proved to be dead, isolated and discharged to earth before
it is examined. Particular care should always be taken to ensure that a voltage transformer is
not liable to be made live inadvertently due to a feedback via the secondary side.

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 AS 2467—2008 64

12.7.2 Maintenance, inspection and verification

Maintenance as described in Clause 12.6 for current transformers is appropriate to voltage
transformers. In addition, the isolating contacts of withdrawable voltage transformers
should be cleaned, inspected for damage, reconditioned as necessary and a film of contact
lubrication sparingly applied. The correct operation of any safety shutters should be
verified. Fuses for the protection of primary windings should be inspected.

12.8 EQUIPMENT EARTHING CONNECTIONS

All exposed earthing connections should be inspected for signs of mechanical damage or
corrosion. The integrity of connections should be verified by suitable means, particularly
with respect to signs of corrosion, for a depth of 150 mm below the ground.

12.9 OTHER AUXILIARY DEVICES

12.9.1 Lifting devices
The maintenance of lifting devices should be carried out at regular intervals. In some types
of switchgear these form an integral part of the equipment and should be dealt with during
the maintenance of the equipment. Some lifting devices are portable and these should be
separately maintained. The manufacturer’s recommendations should be sought and
followed.
12.9.2 Oil handling plant
To ensure satisfactory service, the utmost care in handling the oil is essential and guidance
in this regard is given in AS 1883. For oil handling it is a good practice to have a clean oil
system and a dirty oil system both of which are clearly marked.
Where portable oil handling equipment is used, the pipework and pumps should be carefully
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inspected to ensure that they are free from dirt and water and should be carefully flushed
with clean oil before use.

12.10 REPLACEMENT PARTS

An adequate supply of suitable replacement parts should be ensured. Replacement parts
should be properly stored.

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 65 AS 2467—2008

S E C T I O N 1 3 M A I N T E N A N CE O F
PROTECT IVE APPARATUS

13.1 GENERAL
When commissioning tests on protective apparatus are being carried out, detailed records of
the results should be made to provide a reference for comparison with future routine or
post-fault tests. Up-to-date records of fuse-link ratings and the correct settings of all
protective relays should also be maintained and care should be taken to restore the settings
to their correct value if they are altered during tests. In addition to these records it is
sometimes helpful to have the settings recorded in or on the relay case.

13.2 REMOVAL OF DUST

It is important that dust is wiped from relay covers before these are removed and equally
important that these covers are replaced securely so as to exclude dust.

13.3 CONNECTIONS
If it is necessary to disturb any connections or make temporary connections for test
purposes, it is essential to ensure that these connections are correctly restored before the
circuit-breaker is returned to service.
NOTE: Attention is drawn to the dangerous voltages which may result if the secondary circuit of
a current transformer is opened with the primary circuit energized.

13.4 ROUTINE TRIPPING TESTS

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To avoid damage to the relay mechanism and contacts, the greatest care should be taken
when carrying out routine tripping tests on circuit-breakers by manipulation of the relay.

13.5 PROTECTIVE APPARATUS INCORPORATING SEMICONDUCTORS

When protective apparatus incorporating semiconductors or similar components is being
voltage tested, care must be taken that the test voltage level will not damage these
components.

13.6 INJECTION TESTS

13.6.1 Primary injection
Testing by primary injection or by injection into test windings where these are provided on
the current transformer should be carried out whenever conditions permit, in preference to
secondary injection which may, however, be used for routine tests. Secondary injection
testing at regular intervals is, however, of much greater value than primary injection tests
carried out infrequently.
13.6.2 Secondary injection
Secondary injection tests should be carried out using current injection devices suitable for
the particular relay concerned or by means of test blocks forming part of the switchgear.
The disconnection of small wiring in order to carry out tests is not recommended.

13.7 RELAYS
Tests should be made on protective relays to verify the operating and re-setting times or
pick-up and drop-out values as applicable.
Special test techniques may be required for static relays, and the manufacturer’s
instructions should be consulted.
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 AS 2467—2008 66

SECT ION 14 MA I NTEN ANCE AND T EST IN G

O F I N SU L A T I O N

14.1 GENERAL
The insulation of electrical switchgear should be tested and the results recorded before the
equipment is commissioned. During the life of electrical equipment, insulation resistance
testing will give a good indication of the condition of the equipment and if these tests are
recorded can help in deciding maintenance requirements for the whole equipment.
Although there may be special dispensation in statutory requirements to cater for testing,
adequate precautions must be taken and it is recommended that the access permit procedure
detailed in Appendix A, rules 25 and 26, be used.

14.2 ROUTINE TESTING AND INSPECTION

14.2.1 Materials susceptible to deterioration
Insulation, such as synthetic resin bonded paper or fabric, and impregnated or laminated
wood, is particularly susceptible to the ingress of moisture, overheating or tracking, and
particular attention should be paid to these materials.
14.2.2 Systematic testing and recording methods
Insulation resistance measurements between poles and between poles and earth are
comparatively easily made and are the most suitable for routine tests, but to facilitate their
proper interpretation systematic testing and recording methods are essential. Resistance
tests are strictly comparative, in that for each item tested a rejection value can only be fixed
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on the basis of experience, by comparison with earlier results. For this reason the test
equipment and method used should be the same on each occasion.
Test values obtained should be logged on a standard form designed for the purpose,
together with the humidity and temperature at the time of the test, and in general a steady
fall of resistance over a period of time is a more reliable indication of deterioration than is a
relatively low value which remains reasonably constant.
14.2.3 Measurement of the dielectric dissipation factor tan δ
The measurement of the dielectric dissipation factor tan δ is a preferred method of verifying
the quality of insulation when suitable test equipment is available and applicable.
14.2.4 Lift rods
On lift rods on some circuit-breakers, or on other long pieces of insulation, deterioration
may not occur uniformly and resistance measurements taken over the entire length may not
reveal localized deterioration.
Particular attention should be paid to the lift rods of circuit-breakers where these are made
of hickory or other natural wood. These should be inspected for indications of the wood
opening along the grain and where riveting is employed, for the wood pulling out of the
riveted end.
14.2.5 Ambient temperature
Where practicable, the insulation to be tested should be allowed to reach ambient
temperature before resistance tests are made.

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 67 AS 2467—2008

14.3 ELECTROSTATICALLY GRADED (CONDENSER) BUSHINGS

14.3.1 General
The oil level of oil-filled bushings should be periodically verified, and joints should be
inspected for oil leaks. Resistance measurement should indicate serious ingress of moisture
though it may not reveal partial tracking or internal deterioration.
14.3.2 Ingress of moisture
Where ingress of moisture is suspected, the bushing should be returned to the manufacturer
for examination and treatment.
14.3.3 Sampling of oil
Some bushings are designed to function with the oil at a pressure slightly above
atmospheric to prevent the ingress of moisture. Normally the pressure should not be
released but, if the condition of the oil is suspect, the maintenance manual or manufacturer
of the item should be consulted. For other designs where provision is made for oil sampling,
the electrical condition of the oil should be tested and the results recorded.
14.3.4 Compound-filled bushings
With compound-filled bushings, a resistance measurement will not necessarily indicate the
presence of moisture. Once every five years, where practicable, the space above the
compound should be inspected for signs of moisture ingress. If the presence of moisture is
suspected, the bushings should be returned to the manufacturer to be de-compounded and
subjected to a test to determine the dielectric dissipation factor tan δ.
Where covers have been removed, care should be taken on re-assembly to ensure that all
joints are properly remade. During inspection it should be verified that the earth connection
is satisfactory.
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14.4 OIL BARRIER BUSHINGS

Where practicable, oil barrier type bushings should have the condition of the bottom oil
examined approximately every five years and the bushing flushed and refilled with clean
tested oil if necessary. If the oil is completely renewed the bushing should be allowed to
stand for at least 4 h before being made live in order that the oil may de-aerate. Where
fitted, water sumps should be drained.

14.5 LAMINATED INSULATION

Insulation of the laminated type may be susceptible to the ingress of moisture, particularly
through the edges of the laminate. Tracking, which tends to commence at the sharp corners
of adjacent metalwork and metal fixings, often occurs beneath the surface of the insulation,
and is indicated as a surface blister.
Delamination or cracking of the material may result in mechanical breakdown or may allow
the entry of moisture or carbon with consequent electrical breakdown. High-voltage
resistance testing and visual inspection should provide valuable indication of the dielectric
quality of this type of insulation.

14.6 PORCELAIN INSULATION

Porcelain insulation does not deteriorate, but it may give low resistance readings under
humid conditions. Careful interpretation of test results is necessary and a thorough visual
inspection for cracks or other mechanical damage is as important as electrical tests. It is
recommended that porcelain insulation be cleaned with a suitable industrial solvent to
ensure removal of conducting films that are not always visible to the naked eye.
Consideration should be given to the renewal of anti-pollution grease where appropriate.

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 AS 2467—2008 68

14.7 APPLIED VOLTAGES FOR INSULATION RESISTANCE TESTS

The applied voltages for insulation resistance tests are given in Clause 11.4.2.2.

14.8 POWER FREQUENCY WITHSTAND TESTS AFTER MAINTENANCE

Power frequency withstand tests (pressure tests) conducted at the works of the manufacturer
or on site during initial commissioning, are done primarily to test the integrity of high-
voltage insulation, and to ensure no damage to insulation has occurred during assembly,
transport or erection of the switchgear. After a number of years in service, some forms of
insulation may undergo a slow deterioration process due to the normal working stresses
involved. This process is greatly accelerated by the application of high a.c. stresses, which
should be avoided whenever possible.
If it is desired to subject the equipment to a pressure test after maintenance, consideration
should be given to carrying out tests at voltage levels below those specified for site
commissioning tests.
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© Standards Australia www.standards.org.au

 69 AS 2467—2008

APPENDIX A
EXAMPLE OF ELECTRICAL SAFETY RULES
(Informative)
The electrical safety rules given in this Appendix are reproduced from a publication by the
Energy Authority of N.S.W which has been abolished.
They are included herein as an example of electrical safety rules for good practice.

CONTENTS
Rule

PART I—INTRODUCTION, SCOPE AND DEFINITIONS

Introduction
Scope
Definitions

PART II—GENERAL
All Mains and Apparatus shall be Regarded as Alive until Proved Dead....................................... 1
Danger of Contact with or Close Approach to Exposed Live Mains and Apparatus ....................... 2
Danger of Materials and Apparel which can conduct................................................................... 3
Entering Areas Containing Exposed Live Mains and Apparatus................................................... 4
Operating Circuit Opening and Closing Devices ......................................................................... 5
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Safety Equipment and Insulated and Other Tools ....................................................................... 6

(a) Insulating gloves
(b) Insulating mats and hose
(c) Life-lines
(d) Insulating screens
(e) Operating rods, live line working sticks and live line indicating devices
(f) Low and medium voltage portable electrical equipment
(g) Safety belts
(h) Use and examination of safety equipment and insulated and other tools
Danger Tablets ........................................................................................................................ 7
Use of Tong or Clip-on Ammeters and Other Testing Devices ..................................................... 8
(a) Tong or clip-on ammeters
(b) Use of high-voltage megger and application of low and medium test voltages
Current Transformer Circuits ..................................................................................................... 9
Working in Battery Rooms ...................................................................................................... 10
Labelling for Identification ....................................................................................................... 11

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 AS 2467—2008 70

PART III—LOW AND MEDIUM VOLTAGE

All Low and Medium Voltage Mains and Apparatus shall be Regarded as Alive until Proved Dead 12
Proving Dead Low and Medium Voltage Mains and Apparatus .................................................. 13
Work on Dead Low and Medium Voltage Mains and Apparatus ................................................. 14
Work on Live Low and Medium Voltage Mains and Apparatus ................................................... 15
Work Carried out by Minors..................................................................................................... 16
Energising and De-energising Mains and Apparatus Involving a Neutral Conductor.................... 17

PART IV—HIGH-VOLTAGE
All High-voltage Mains and Apparatus shall be Regarded as Alive Until Proved Dead ................ 18
Minimum Safe Working Distances ........................................................................................... 19
Working on High-voltage Mains and Apparatus ........................................................................ 20
Isolation of High-voltage Mains and Apparatus......................................................................... 21
Proving Dead High-voltage Mains and Apparatus ..................................................................... 22
Earthing and Short-Circuiting High-voltage Mains and Apparatus .............................................. 23
White Tape Barriers................................................................................................................ 24
Access Permit for Working on High-voltage Mains and Apparatus ............................................. 25
Preparation, Issue and Cancellation of Access Permits ............................................................ 26
Commissioning of New High-voltage Mains and Apparatus ....................................................... 27
High-voltage Cables ............................................................................................................... 28
Identification of High-voltage Cables Before Working on Them ................................................. 29
Working on Voltage Transformers ........................................................................................... 30
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Sample Access Permit Form

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 71 AS 2467—2008

ELECTRICAL SAFETY RULES

PART I
INTRODUCTION, SCOPE AND DEFINITIONS

INTRODUCTION
These Rules are expressed in mandatory terms as they set forth only minimum requirements for the
safeguarding of persons exposed to electrical hazards in electrical stations. Nevertheless, they are
framed in such a manner that they could be adopted by supply authorities as working procedures.
Any supply authority is at liberty to frame safety rules to meet its own requirements but care should
be exercised to guard against any conflict with these Rules.
Every employer shall ensure that all employees engaged on work in electrical stations—
(i) receive a copy of these Safety Rules or the employer’s own safety rules or receive appropriate
instruction relating thereto;
(ii) are instructed in emergency first-aid procedure and by a practical demonstration, indicate their
ability to apply such emergency first-aid procedure: Provided that instruction in emergency
first-aid procedure need not be given to persons employed in electrical stations in which staff
trained in first-aid are employed.
For the purpose of these Rules, emergency first-aid procedure means the procedure for
releasing a person from live conductors and applying resuscitation as approved by the
Authority for purposes of the Overhead Line (Workers) Regulations, 1964. A copy of the
approved procedure published by the Authority, shall be issued to each such employee.
Where practicable there shall be displayed in all electrical stations, detailed instructions in the
release of a person from live conductors and the treatment of persons who have received injury from
electric shock.

SCOPE
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The Rules are intended for the guidance of electricity supply authorities and their employees who are
engaged on work on mains and apparatus in electrical stations. However, the Rules are also
intended to apply to any other employee or person, including visitors, workmen, etc., who may enter
an electrical station.
The requirements of the Overhead Line (Workers ) Regulations 1964, shall be observed by all
employees who carry out work on overhead lines in electrical stations. A copy of the Regulations
shall be issued to all such employees as the Regulations and these Rules are to be taken as
complementary.
These Safety Rules do not cover persons or work associated with—
(i) direct current traction systems, including associated direct current converting equipment in
electrical stations and all connections and plant up to and including the secondary side of the
power transformers feeding the converters or rectifiers;
(ii) extra low voltage installations;
(iii) equipment in the course of construction in a locality where there is no possibility of its making
contact with live conductors;
(iv) equipment which has been removed from its normal operating location to undergo repair or
overhaul.

DEFINITIONS
Throughout the Rules, terms printed in italic type shall have the defined meaning given. Where terms
are not printed in italic type they shall be interpreted as the context or subject matter indicates or
requires
Alive or Live is the term applied to a conductor or circuit when a potential difference exists between it
and earth.
Authorised employee means a person appointed or selected by an employer to carry out specific
duties associated with the generation or distribution of electricity, such person being competent for
the purposes of the rule in which the term is used.
Dead means not alive.
Earthed means electrically connected to the general mass of earth.

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 AS 2467—2008 72

Electrical station means generating station, substation or switching station, whether of the
indoor, outdoor, underground or pole-mounted type.
Employer means an electricity supply authority.
Exposed means bare or not effectively insulated or not effectively guarded by either a fixed
barrier or an earthed metal shield.
Isolated means disconnected from all possible sources of supply.
Mains and Apparatus means that part of a conductor, cable, machine, transformer, switch or other
equipment which is normally subject to an electric charge.
Switching station means any premises or structure containing or carrying switchgear, but does not
include any structure carrying only one switch and/or fuse unit.
Voltage means potential differences between conductors of the following values:—
Extra Low—Normally not exceeding 32 volts alternating current or 115 volts direct
current.
Low—Normally exceeding 32 volts alternating current or 115 volts direct current, but
not exceeding 250 volts in either case.
Medium—Normally exceeding 250 volts, but not exceeding 650 volts.
High—Normally exceeding 650 volts.

PART II
GENERAL

1. ALL MAINS AND APPARATUS SHALL BE REGARDED AS ALIVE UNTIL PROVED

DEAD

2. DANGER OF CONTACT WITH OR CLOSE APPROACH TO EXPOSED LIVE MAINS

AND APPARATUS
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When working on exposed live low or medium voltage mains and apparatus adequate precautions
shall be taken otherwise injury or death may result.
Contact with exposed live high-voltage mains and apparatus is almost certain to cause severe injury
or death. Therefore, except as set out in Rule 20, employees shall not—
(a) bring any portion of their bodies within the minimum safe working distance (See Rule 19) of
any exposed live high-voltage mains and apparatus;
(b) bring any material (other than equipment issued for testing, operating or working on live high-
voltage mains and apparatus) which is being carried or is otherwise in contact with their
bodies within the minimum safe working distance of exposed live high-voltage mains and
apparatus.
If any employee is in doubt as to the safe performance of any work assigned to him on or near
exposed live mains or apparatus he shall request further instructions from his supervisor.

3. DANGER OF MATERIALS AND APPAREL WHICH CAN CONDUCT

All materials, including liquids and gases shall be regarded by employees as conducting materials
unless they have definite knowledge to the contrary. In particular, it should be noted that
(a) Earth, concrete, and wet or damp timber are conducting materials;
(b) Flame conducts electricity and care must be exercised when using flame producing
equipment. Blow lamps are liable under certain circumstances to throw a long stream of flame
and liquid;
(c) Metal objects, such as portable radio telephone units with telescopic aerials, rules, tapes,
torches and the like, must be handled with care when working on or near exposed live mains
and apparatus to avoid contact with exposed live mains and apparatus;
Certain wearing apparel, such as metallic belts, clothing with metal threads, etc., can also be
hazardous when working on or near exposed live mains and apparatus.
(d) The liquids of certain fire extinguishers are conductive.

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 73 AS 2467—2008

4. ENTERING AREAS CONTAINING EXPOSED LIVE MAINS AND APPARATUS

No person shall enter areas where there are exposed live mains and apparatus unless the person is
(a) an authorised employee; or
(b) accompanied by an authorised employee; or
(c) clearly instructed on the site by an Authorised employee to work or remain in the safe sections
of the area.

5. OPERATING CIRCUIT OPENING AND CLOSING DEVICES

Circuit opening and closing devices shall be operated only by employees authorised to do so except
that they may be operated by any person in an emergency for the purpose of saving life or property.

6. SAFETY EQUIPMENT AND INSULATED AND OTHER TOOLS

(a) Insulating gloves issued to employees for work on or near exposed live low and medium
voltage mains and apparatus shall not be used on live high-voltage mains and apparatus
except when used in conjunction with insulated operating sticks and the like.
Gloves shall be kept in a suitable container.
The employee to whom the gloves are issued shall air test* them once daily, prior to use.
(b) Insulating mats and hose. Insulating mats and hose are for use by employees when working
on or adjacent to exposed live low and medium voltage mains and apparatus. Their purpose is
to insulate the employee’s body from
(i) Earth;
(ii) Exposed live low and medium voltage mains and apparatus.
When insulating mats and hose are used to cover conductors, they shall be securely fixed to
prevent their displacement.
(c) Life-lines consisting of not less than two-inch first grade manilla rope marked with tufts of red
bunting or with red paint at each end or by a non-conducting red marker incorporated in the
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rope, shall always be readily available for use where an employee is working on or above live
overhead conductors and when not in use, shall be kept in the box provided.
Life-lines shall be used only for rescue work and shall be inspected at least every three
months.
(d) Insulating Screens are portable barriers made of wood or other insulating materials and are
used as a protection against accidental contact with exposed live mains and apparatus when it
is necessary for an employee to work in close proximity to such live mains and apparatus.
When in use screens shall be securely fixed or supported and shall not be used resting in
contact with live high-voltage mains and apparatus.
When, during erection, use or removal, it is possible for a screen to accidentally come in
contact with live high-voltage mains and apparatus, only screens specially provided for the
purpose shall be used. These screens shall be tested at least every three months.
(e) Operating Rods, Live Line Working Sticks and Live Line Indicating Devices.†
(i) All the operating rods used for opening and closing, disconnecting switches or for other
purposes involving contact with live conductors and all live line indicating devices must,
when not in use, be kept in a dry clean place and on the supports where such are
provided. Care must be taken in the handling of the rods so as not to damage the
surface. Before use, the rods must be examined and, when necessary, wiped
thoroughly with a clean, dry cloth. Should an operating rod be cracked or the surface be
damaged or should other defects be apparent; the rod must not be used and shall be
withdrawn from service and arrangements made for its replacement.
(ii) All rods and live line indicating devices shall be marked with the voltage for which they
are suitable and shall not be used for higher voltages.
(iii) An employer shall cause all rods and sticks to be examined at least every twelve
months.

* Gloves can be air tested simply by rolling the glove from the cuff to force air into the fingers
† The term ‘live line indicating devices’ includes voltage test sticks, line testers and like equipment used for
proving dead mains and apparatus.

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 AS 2467—2008 74

(f) Low and medium voltage portable electrical equipment. An employer shall cause all low
and medium voltage portable electrical equipment to be regularly examined and maintained to
ensure that the equipment and leads are in good order.
Insulation resistance tests and earth lead continuity tests shall be carried out on all low and
medium voltage portable electric hand tools and extension leads at least every six months.
(g) Safety Belts. When an employee is working in an elevated position, and not on a proper
scaffold or railed platform, he shall use where practicable, the safety belt and strap or rope
issued. Before trusting his weight to the belt, an employee shall ensure that the fastenings are
properly engaged and that he is secure in his belt.
When climbing or changing his position whilst wearing a safety belt, an employee shall secure
the free ends of the pole strap or rope to his body in such a manner as to ensure that they do
not hinder his safe movement.
An employer shall cause safety belts to be tested at least every three months.
(h) Use and Examination of Safety Equipment and Insulated and other Tools. Employees
working on or near live mains and apparatus shall use in a proper manner the safety
equipment and insulated tools provided. Before use, such equipment and tools shall be
examined and not used unless they are in good condition.
Employees shall immediately report all defects they observe in safety equipment.
In wet weather and damp places the insulation of safety equipment and insulated tools may be
less effective and greater care should be taken.

7. DANGER TABLETS
Danger tablets are boards, plates or tags on which the word ‘Danger’ is boldly marked and are a
warning against inadvertent and unauthorised operation of circuit opening and closing and other
controlling devices.
They shall be attached to the controls of such devices for this purpose or if this is impracticable they
shall be attached in such a position as to arrest the attention of any person about to operate the
circuit opening and closing device, or other controlling device. Danger tablets shall not be interfered
with and may be removed only by authorised employees.
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8. USE OF TONG OR CLIP-ON AMMETERS AND OTHER TESTING DEVICES

(a) Tong or clip-on ammeters are generally used on low or medium voltage conductors and if
suitable for the purpose they may also be used on high-voltage conductors.
In either case an employee shall not use tong or clip-on ammeters unless he has been
instructed in the precautions which must be observed in their use.
(b) Use of high-voltage megger and application of low and medium test voltages. An
employee shall neither use a high-voltage megger nor apply low or medium test voltages to
any mains and apparatus unless he has warned all persons working on the mains and
apparatus of the proposed test and has received assurances that everyone will stand clear of
such mains and apparatus during the test.

9. CURRENT TRANSFORMER CIRCUITS

The secondary circuit of a current transformer shall not be opened whilst the primary circuit is alive
unless the secondary winding of the current transformer has been short-circuited. Failure to do this
may result in dangerous voltages occurring at the secondary terminals.

10. WORKING IN BATTERY ROOMS

Persons working in battery rooms while lead burning is in process or while cells are being charged
and gassing, shall ensure that the battery room is adequately ventilated.

11. LABELLING FOR IDENTIFICATION

Where the identity of a switch, transformer, cable, end box or termination etc. is not obvious, it must
be clearly labelled. When connections to mains and apparatus are so altered as to necessitate the
changing of labels, such labels shall be altered to conform to the changed circumstances.

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 75 AS 2467—2008

PART III
LOW AND MEDIUM VOLTAGE

12. ALL LOW AND MEDIUM VOLTAGE MAINS AND APPARATUS SHALL BE
REGARDED AS ALIVE UNTIL PROVED DEAD

13. PROVING DEAD LOW AND MEDIUM VOLTAGE MAINS AND APPARATUS
Low and medium voltage mains and apparatus shall be proved dead by means of approved test
lamps, suitable indicating device or voltmeter. Where practicable this test equipment shall be proved
to be in good working order immediately before and after use.

14. WORK ON DEAD LOW AND MEDIUM VOLTAGE MAINS AND APPARATUS
When work is to be carried out on dead low and medium voltage mains or apparatus such mains and
apparatus shall be—
(i) isolated from all possible sources of supply; and
(ii) proved dead; and
(iii) clearly labelled at points of isolation from supply to warn persons against the operation of the
isolating devices; and
(iv) where directed, short-circuited and earthed.

15. WORK ON LIVE LOW AND MEDIUM VOLTAGE MAINS AND APPARATUS
Work on live low or medium voltage mains and apparatus shall be carried out only by persons trained
in the safe performance of such work.

16. WORK CARRIED OUT BY MINORS

An employee under 21 years of age shall not work on live low or medium voltage mains and
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apparatus, unless he has had three years training in electrical work and has reached the age of 18
years or such work is carried out under the direct supervision of an adult person trained in the safe
performance of that work (see Rule 15).

17. ENERGISING AND DE-ENERGISING MAINS AND APPARATUS INVOLVING A

NEUTRAL CONDUCTOR
When connecting and disconnecting mains and apparatus the neutral conductor shall be connected
first and disconnected last.

PART IV
HIGH-VOLTAGE

18. ALL HIGH-VOLTAGE MAINS AND APPARATUS SHALL BE REGARDED AS ALIVE

UNTIL PROVED DEAD

19. MINIMUM SAFE WORKING DISTANCES

Where employees work in the vicinity of exposed live high-voltage mains and apparatus they shall
not allow any portion of their bodies or any object or tool (other than equipment issued for testing,
operating or working on live high-voltage mains and apparatus) which they are handling to come
within the following minimum safe working distances from exposed live high-voltage mains and
apparatus.
Nominal system Voltages Distances
Above 650 volts but not exceeding 11,000 volts — 18 inches
Above 11,000 volts but not exceeding 33,000 volts — 2 feet
Above 33,000 volts but not exceeding 66,000 volts —3 feet
Above 66,000 volts but not exceeding 132,000 volts — 5 feet
Above 132,000 — 10 feet

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 AS 2467—2008 76

When it is likely that an employee’s body or any object which he might be carrying would come within
the distances specified above, insulating screens must be erected (see Rule 6(d)) or the exposed live
high-voltage mains and apparatus must be made dead and isolated and earthed in accordance with
Rule 20.

20. WORKING ON HIGH-VOLTAGE MAINS AND APPARATUS

Except when authority is given and special tools and equipment are provided for working on live high-
voltage mains and apparatus, high-voltage mains and apparatus shall not be worked on until—
(a) They have been isolated from all possible sources of supply; and
(b) Danger tablets have been displayed on or adjacent to all devices and controls through which
the mains and apparatus may be energised; and
(c) They have been proved dead; and
(d) They have been earthed and short-circuited; and
(e) White tape barriers have been erected where necessary; and
(f) An access permit, it has been issued in accordance with Rule 25.
Where high-voltage mains and apparatus to be worked on are divided into two or more sections, this
Rule shall be observed with regard to each section.
Note: It should be remembered that voltage transformers as well as power transformers are a possible source of
high-voltage supply and care must be taken to ensure that they are isolated on both the high and low voltage
sides.

21. ISOLATION OF HIGH-VOLTAGE MAINS AND APPARATUS

Isolation of high-voltage mains and apparatus from a source of supply shall be effected by making a
break in the electrical circuit—
(a) by means of a switch or isolators; or
(b) by unbolting and removing or separating connections.
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22. PROVING DEAD HIGH-VOLTAGE MAINS AND APPARATUS

Only approved devices issued for proving dead high-voltage mains and apparatus shall be used.
Immediately before and immediately after use of testing equipment for the purpose of ascertaining if
high-voltage mains and apparatus are dead, such equipment shall be checked to prove that the
equipment is in proper working order: Provided that if the testing equipment cannot be so checked,
the high-voltage mains and apparatus shall be re-checked with duplicate testing equipment.

23. EARTHING AND SHORT-CIRCUITING HIGH-VOLTAGE MAINS AND APPARATUS

(1) Mains and Apparatus other than Overhead Lines
Except as provided below, mains and apparatus to be worked on shall be earthed and short-circuited
as close as possible to the site of the work.
Earthing and short-circuiting equipment shall be adequate to carry the short-circuit currents which
may flow and shall remain in position for the duration of the work.
Exception—
High-voltage mains and apparatus (on which work is to be carried out) need not be short-circuited
and earthed provided that—
(a) the work which it is proposed to carry out—
(i) is work on draw-out type equipment which has been withdrawn clear of live conductors;
or
(ii) is work on dismantled high-voltage equipment on which it is impracticable to use fixed
earths; or
(iii) could not be carried out if earth leads were used; or
(iv) is work on busbars to which it is impracticable to attach earth leads of adequate size; or
(v) involves the application of test voltages;
and that

© Standards Australia www.standards.org.au

 77 AS 2467—2008

(b) after the mains and apparatus have been isolated, and immediately before the work is
commenced, the conductors are momentarily connected to earth.
(2) Overhead High-voltage Lines
The Overhead Line (Workers) Regulations, 1964, provide for the earthing and short-circuiting of
overhead high-voltage lines as follows—
(a) Earthing and short-circuiting of a high-voltage overhead line shall be effected at a place which,
where practicable, is visible from the site where work is to be carried out on such line.
(b) Such earthing and short-circuiting shall be carried out on both sides of the working site where
practicable.
(c) Where no known permanent earthing facilities are available, earth connection shall be made
by means of a metal rod not less than half inch diameter or a metal stake of equivalent cross
sectional area driven vertically into the ground to a depth not less than two feet.
(d) Except in a case of emergency involving danger to human life, a person shall not earth or
short-circuit a high-voltage overhead line otherwise than with equipment provided by his
employer for the purpose.

24. WHITE TAPE BARRIERS

White tape shall be used where practicable in an approved manner to indicate as clearly as possible
the area in which work is to be performed and to indicate the dividing line between live mains and
apparatus and the mains and apparatus on which it is safe to perform work.
The tape shall be so arranged that the mains and apparatus to be worked on is accessible without
interfering with the tape or stepping over or under the tape and to indicate a clearly defined path of
access for employees to the working area.
Employees shall not pass over or under or interfere with any white tape.
If during the course of the work it becomes necessary to move items of plant or material into or out of
the working area and these are too large to pass through the marked path of access, the Authorised
employee in charge may re-arrange the tape to mark a safe path of access during movement of the
plant or materials following upon which the tape must be restored to its original position.
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Note: This rule shall not preclude an authorised officer, having an appropriate reason for doing so, from
temporarily moving tape for the purpose of making an examination or for the purpose of gaining access to an
area in circumstances where such access cannot otherwise be obtained.

25. ACCESS PERMIT FOR WORKING ON HIGH-VOLTAGE MAINS AND APPARATUS

Before any work may be carried out on high-voltage mains and apparatus an Access Permit (see
sample with these Safety Rules) must be issued for the mains and apparatus concerned.
Note: For the purpose of this Rule, work of an operational nature, including the operation of switches,
the opening and closing of links and the removal and replacement of fuses, shall not be deemed to
be work on mains and apparatus.
This Rule may be departed from only in the following circumstances:—
(a) When mains and apparatus have failed and supply is urgently required and temporary repairs
are to be carried out under the sole charge of the Authorised employee who carried out the
isolation, earthing and short-circuiting of the mains and apparatus in accordance with these
Safety Rules.
(b) When so authorised by the Chief Electrical Engineer,* an employee may work on mains and
apparatus which he has isolated, proved dead and earthed and short-circuited in accordance
with these Safety Rules, provided that he and his assistant only, are working on the mains and
apparatus concerned.

26. PREPARATION, ISSUE AND CANCELLATION OF ACCESS PERMITS

The Access Permit Form issued in accordance with Rule 25 shall conform generally to the sample
included with these Safety Rules.
Access Permits shall be issued only by authorised employees.

* Chief Electrical Engineer includes Chief Engineers, Electrical Engineers in charge and persons for the time
being acting in those positions.

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 AS 2467—2008 78

The issuing officer shall enter the details of the mains and apparatus which may be worked on and
shall certify that the following requirements have been carried out:
(a) Switching operations to isolate the mains and apparatus.
(b) The earthing of the mains and apparatus.
(c) Warnings (if any) of nearby live mains and apparatus.
(d) Temporary screens (if any) erected.
(e) White tape barriers erected.
He shall then sign the Permit and enter the time and date of issue.
Note: If the space provided for the entry of any of the above items is not used, it shall be ruled out leaving no
blank spaces on the Permit.

The person in charge of the work shall sign the Permit as the recipient and shall enter the time and
date of receipt. He shall then ensure that all persons who are to work on the mains and apparatus
covered by the Permit, sign on and enter the time and date before they commence work.
When the work has been completed or is stopped the person in charge shall ensure that all persons
who worked on the job sign off and enter the time and date to indicate that they are aware that the
safe working period has terminated. He shall then sign the Permit, enter the time and date and return
the Permit to the issuing officer or to the authorised relieving officer.
The issuing officer or the authorised relieving officer shall then cancel the Permit and enter the time
and date.
Before making the mains and apparatus alive, the person responsible shall ensure that all relevant
access permits have been cancelled.
Immediately the Access Permit has been cancelled, all danger tablets and white tape barriers
erected for the work associated with the particular Permit shall be removed.
If during the course of the work the conditions governing the issue of the Permit are to be changed,
the Access Permit shall be cancelled. A new Access Permit shall then be issued if the work is
required to proceed.
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27. COMMISSIONING OF NEW HIGH-VOLTAGE MAINS AND APPARATUS

Before new high-voltage mains and apparatus are energised, by the application of test voltages or
otherwise, adequate precautions shall be taken to ensure that all persons who have been engaged
on the work are clear of the mains and apparatus and will henceforth regard the mains and apparatus
as being alive.

28. HIGH-VOLTAGE CABLES

High-voltage cables not completely covered by an earthed metal sheath shall not be handled when
alive.

29. IDENTIFICATION OF HIGH-VOLTAGE CABLES BEFORE WORKING ON THEM

Usually it is not possible to prove dead, earth and short-circuit metal sheathed high-voltage cables
close to the location where work is to be carried out on them. In these circumstances the cable must
be proved dead and earthed and short-circuited at each point of isolation, in accordance with Rule 23
and then identified at the point where the work is to be carried out, either by an approved test or by
tracing it visually.
Labels on cables or drawings must not be relied upon as a positive means of identification.
After identification, spiking or stabbing of the cable should be carried out. If spiking or stabbing of the
cable is undesirable, the employer shall instruct staff on the additional precautions to be taken before
the cable is opened or cut.

30. WORKING ON VOLTAGE TRANSFORMERS

Before working on voltage transformers (see Rule 20) other than draw-out type, isolation, earthing
and short-circuiting of the high-voltage windings and isolation of all secondary windings of the
voltage transformer shall be carried out.

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 79 AS 2467—2008

ACCESS PERMIT FORM

THE (Name of Electricity Supply Authority) .................................. No. ..................................

ACCESS PERMIT FOR WORKING ON HIGH-VOLTAGE MAINS AND APPARATUS

1. Issued to: .........................................................................................................................
2. This Permit allows work to be carried out on:
........................................................................................................................................
........................................................................................................................................
The Permit is issued only for this work and in respect of the mains and apparatus specified. It
is valid so long as it is in the possession of the person in charge of the work.
3. Statement by person issuing Permit:
I hereby certify that the following requirements of (name of safety rules etc. of electricity
supply authority) have been carried out:
(a) Switching operations carried out to isolate the mains and apparatus...........................
(b) Mains and apparatus earthed at ...............................................................................
(c) Warnings (if any) of nearby live mains and apparatus ................................................
(d) Temporary screens etc. (if any) erected ....................................................................
(e) White tape barriers erected ......................................................................................
Signed ................................................. Time .................. Date ....................................
(Issuing Officer)
4. Statement by person receiving Permit:
I hereby acknowledge having received this Permit and state that I fully understand my duties. I
am aware of the nature and position of the mains and apparatus covered by the Permit. I fully
understand that all mains and apparatus other than those referred to above in this Permit as
having been made available for work, are to be treated as being alive, and I am fully aware of
the danger of contact with live mains and apparatus. I am satisfied that I and the persons
under my control and authorised by me to work on the mains and apparatus referred to should
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have no difficulty in keeping clear of live mains and apparatus in the course of work.
Signed ................................................ Time .................. Date ....................................
5. Statement by persons under the control of and authorised by the recipient of this Permit to
work on the mains and apparatus referred to in this Permit:
Issue Cancellation
I/We the undersigned hereby acknowledge I/we the undersigned hereby acknowledge
having received instruction to carry out having received instruction to discontinue
work on the mains and apparatus referred work on the mains and apparatus referred to
to in this Permit and am/are satisfied that in this Permit and I/we will henceforth regard
I/we should have no difficulty in keeping the mains and apparatus as being alive.
clear of live mains and apparatus in the
course of my/our work.
(1) Sgd .......... Time ...... Date ......... Sgd .................. Time .......... Date .........
(2) ‘ ............... ‘............. ‘ ............... ‘ .................. ‘................. ‘ ...............
(3) ‘ ............... ‘............. ‘ ............... ‘ .................. ‘................. ‘ ...............
(4) ‘ ............... ‘............. ‘ ............... ‘ .................. ‘................. ‘ ...............
(5) ‘ ............... ‘............. ‘ ............... ‘ .................. ‘................. ‘ ...............
(6) ‘ ............... ‘............. ‘ ............... ‘ .................. ‘................. ‘ ...............
(7) ‘ ............... ‘............. ‘ ............... ‘ .................. ‘................. ‘ ...............
(8) ‘ ............... ‘............. ‘ ............... ‘ .................. ‘................. ‘ ...............
6. Cancellation of Permit for work:
I hereby state that the work on the mains and apparatus allocated to me under this Permit is
now completed/stopped, and that all persons authorised by me to work are now clear of the
mains and apparatus referred to. I hereby relinquish the Permit and state that I henceforth
regard the mains and apparatus as alive.
Signed ................................................ Time .................. Date ....................................
(Recipient of Permit)

This Permit is hereby cancelled.

Signed ................................................ Time .................. Date ....................................
(Issuing Officer or Authorised Relief)

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 AS 2467—2008 80

APPENDIX B
MAINTENANCE RECORD FORMS
(Informative)
This Appendix gives examples of typical maintenance record forms (Figures B1 to B4).
Figure B1, Fault Openings Form, is a form used to list the operations of individual items of
equipment.
Figure B2, Equipment Maintenance Required Form, is a form used to request maintenance
on a specific item of equipment.
Figure B3, Record of Circuit-breaker Maintenance Form, is a form used by maintenance
staff to record work which has been carried out.
Figure B4, Circuit-breaker History Form, is compiled from information reported on
Figure B3. This form is used to record the complete history of maintenance carried out on
the circuit-breaker.

FAULT OPENINGS ON EQUIPMENT NO. . . . . . . . . . . . . .LOCATION . . . . . . . . . . . . . .

DATE DOWNTIME PHASE
OFF ON R Y B E/L Number of Total fault REMARKS (Cause of fault, location,
recloses opns since etc.)
last O/H
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FIGURE B1 FAULT OPENINGS FORM

© Standards Australia www.standards.org.au

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www.standards.org.au

Distribution: .......................................................... SECTION From:

.............................................................................. ..................................................................................
..................................................................................

EQUIPMENT MAINTENANCE REQUIRED

Date: / /

LOCATION EQUIPMENT MAINTENANCE REASON PRIORITY ALLOCATION REMARKS

REQUIRED

81
© Standards Australia

AS 2467—2008
SIGNED .....................................................................

FIGURE B2 EQUIPMENT MAINTENANCE REQUIRED FORM

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© Standards Australia

AS 2467—2008
RECORD OF CIRCUIT-BREAKER MAINTENANCE
DATE: / / STATION: ..................................................................................................... PLANT No: .................................................
MAKE:......................................... TYPE ............................... SERIAL No ............................... PART No ....................................................

TYPES OF MAINTENANCE*: Inspection □: Oil Change □: Routine □: After fault □: Emergency □: Other ...............................................
(*Tick one or more as necessary)
REPORT: Tick (√) items completed, cross (X) items not done, and/or write in readings observed:
AS FOUND ACTION ON COMPLETION
COMPONENT REMARKS
R Y B YES NO R Y B
Operation counter reading
Insulation resistance (Megger volts . . . . )
Contact resistance (Ducter)
Pollution on bushings
Oil—Visual (colour, carbon, clarity, etc.)
Breakdown voltage (kV)
Moisture (crackle test)
Acidity
Contact assembly
Ace-control devices

82
Insulation
Inspection of operating mechanism
Clean, oil and adjust operating mechanism
Auxiliary switches
Control switches—Local and remote
Control cables and connections
Lights and heaters
Main connections and busbars
Earthing and bonding
Other
Reasons for non-completion or items marked X:__________________________________________________________________________________________________________
________________________________________________________________________________________________________________________________________________
Spares used (quote catalogue number were possible) _____________________________________________________________________________________________________
www.standards.org.au

REMARKS (Unrepaired defects, further attention required, follow-up inspection required, etc.):
________________________________________________________________________________________________________________________________________________
________________________________________________________________________________________________________________________________________________
__________________________________________________________________________________________________________ ..........................................................
Party Leader

FIGURE B3 RECORD OF CIRCUIT-BREAKER MAINTENANCE FORM

 83 AS 2467—2008

(INDOOR (OIL (SINGLE TANK

CIRCUIT-BREAKER ( ( ( PLANT No .........................
(OUTDOOR (AIR BLAST (MULTI TANK

Maker: .................................... Type: ............................... Serial No:............................. Voltage: ......................... kV

Current: .............. A. Rupturing Cap: .............................. MV.A No of CT: ......................... Ratio: ............. (through type
(wound type

Closing: ......................................................... Tripping: ............................................... Coil voltage: ..................................

Contract No.: ................................................. File No.: ................................................ Bushings: ......................................

REMARKS: ............................................................................................................................................................................

.............................................................................................................................................................................................

LOCATION DEVICE No DATE IN DATE OUT

DATE SHEET No MAINTENANCE RECORD

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FIGURE B4 CIRCUIT-BREAKER HISTORY FORM

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 AS 2467—2008 84

APPENDIX C
FIRE PROTECTION EQUIPMENT
(Informative)

C1 AUTOMATIC CONTROL
The following procedures shall be carried out before work or inspections are undertaken in
any enclosure protected by automatic fire extinguishing equipment:
(a) The automatic control shall be rendered inoperative and the equipment left on hand
control. A Caution Notice shall be attached.
(b) Suitable breathing apparatus shall first be checked for correct operation and placed
ready at the work site.
(c) Precautions taken to render the automatic control inoperative shall be noted on any
Permit-to-Work or written instruction issued for work in the protected enclosure.
(d) The automatic control shall be restored after the persons engaged on the work or
inspections have withdrawn from the protected enclosure.

C2 PORTABLE EXTINGUISHERS
Before any work proceeds a check shall be made to ensure that portable extinguishers are in
the vicinity of the work site. Only approved portable extinguishers shall be used in the
vicinity of live electrical apparatus provided that in the handling of extinguishers safety
clearances are maintained. After the discharge of portable extinguishers in an enclosed
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space, personnel shall leave the space until the precautions set out in Paragraph C3 have
been taken.

C3 VENTILATION OF ENCLOSED SPACE

After an explosion or fire, or after the discharge of extinguishers, in an enclosed space, no
personnel are to be allowed entry, unless wearing suitable breathing apparatus, until the
space is thoroughly ventilated and purged with fresh air.

© Standards Australia www.standards.org.au

 85 AS 2467—2008

APPENDIX D
GRAPHICAL ILLUSTRATION OF SOME OF THE TERMS AND DEFINITIONS
GIVEN IN CLAUSE 1.4
(Informative)

N ew
M a n u fac tu re r’s
s t a n d a rd R e s to r ati o n s t a n d a rd
CONDITION

Ac c e pta b l e Preve nti ve C o r re c ti ve

c o n d i ti o n m a i nte n a n c e m a i nte n a n c e

M i n i m u m ac c e pta b l e c o n d i ti o n

U n ac c e pt a b l e G rad u a l Sudden
Fa i l u re c o n d i ti o n f a i l u re f a i l u re

TIME

FIGURE D1 GRAPHICAL ILLUSTRATION OF SOME OF THE TERMS AND

DEFINITIONS GIVEN IN CLAUSE 1.4
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 AS 2467—2008 86

APPENDIX E
APPROPRIATE ACTS AND REGULATIONS
(Informative)

E1 GENERAL
Individual States in Australia have gazetted specific Acts and Regulations which cover all
or some of the matters listed in Paragraph E2 and which may be of concern to persons
involved with maintenance of electrical switchgear.

E2 LIST OF MATTERS WHICH MAY BE COVERED BY STATE ACTS AND

REGULATIONS
1 The prevention or reduction of work injuries and the action to be taken on the
occurrence of any work injury.
2 The construction, maintenance, access to, care and use of, any building structure or
place comprised in any workplace.
3 Certificates of competency for persons engaged in prescribed work.
4 Compressed air work.
5 The handling, prohibition of use, use and storage of dangerous, flammable and
harmful substances.
6 Electrical distribution and wiring.
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7 Examination and testing of equipment.

8 Fire precautions and fire protection equipment.
9 The safety of employees engaged in isolated situations.
10 Machinery, power-driven equipment, and explosive-powered tools including—
(a) safety standards to be complied with in respect of machinery, whether portable,
movable, or fixed, power-driven equipment, and explosive-powered tools
intended for use in or in connection with industry;
(b) the persons who may work, maintain or have charge of machinery, power-
driven equipment, and explosive-powered tools;
(c) the protection of persons in the vicinity of any machinery or power-driven
equipment and explosive-powered tools;
(d) the maintenance and safeguarding of machinery, power-driven equipment, and
explosive-powered tools; and
(e) the installing, dismantling, cleaning, working and testing of machinery, power-
driven equipment, and explosive-powered tools.
11 Boilers and pressure vessels and associated equipment.
12 The handling and storage of materials.
13 The protection of persons in workplaces from areas of hazard.
14 Protective clothing, protective equipment, and rescue equipment.
15 Safety supervisors.
16 Scaffolding, formwork, falsework, and related equipment.

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 87 AS 2467—2008

17 The protection of health of employees in industry, including—

(a) the prevention and control of dust;
(b) the prevention of the escape of poisonous or deleterious vapours, fumes, and
gases;
(c) apparatus for collecting, filtering, and preventing the inhalation of dust, vapour,
fumes, and gases; and
(d) mechanical appliances to assist ventilation.
18 Ventilation, heating, cooling, humidity, air space, and floor space.
19 First-aid, medical, and nursing facilities and arrangements.
20 Lighting.
21 Noise levels and protection from noise.
22 The medical examination of employees.
23 The protection of persons in the vicinity of workplaces.
24 Maximum loads that may be lifted manually by any employee of a prescribed class or
kind.
25 The powers and duties of authorized officers.
26 The inspection of workplaces.
27 The responsibilities and duties of owners or occupiers of workplaces.
28 The form of records, returns, notices, documents to be used, and information to be
kept, given or furnished for the purpose of this Act, and the keeping, giving, or
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furnishing thereof.
29 Employees’ safety representatives.

E3 EXAMPLES OF ACTS AND REGULATIONS IN FORCE IN INDIVIDUAL

STATES OF AUSTRALIA
E3.1 General
The following lists of Acts and Regulations have an application to the maintenance of
electrical switchgear, however specific matters may not be covered and reference to other
Acts and Regulations not listed may be necessary.
E3.2 New South Wales
Occupational Health and Safety Act 2000.
E3.3 Victoria
Occupational Health and Safety Act 2004.
E3.4 Queensland
Workplace Health and Safety Act 1995.
E3.5 South Australia
Occupational Health, Safety and Welfare Act 1986.
E3.6 Western Australia
Occupational Safety and Health Act 1984.
E3.7 Tasmania
Workplace Health and Safety Act 1995.

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 AS 2467—2008 88

E3.8 Northern Territory

Work Health Act 1986.
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© Standards Australia www.standards.org.au

 89 AS 2467—2008

APPENDIX F
REFERENCED DOCUMENTS
(informative)

REFERENCED STANDARDS
AS
1265 Bushings for alternating voltages above 1000 V
1319 Safety signs for the occupational environment
1883 Guide to maintenance and supervision of insulating oils in service
2067 Switchgear assemblies and ancillary equipment for alternating voltages above
1 kV
2184 Low voltage switchgear and controlgear—Moulded-case circuit-breakers for
rated voltages up to and including 600 V a.c. and 250 V d.c.
2225 Insulating gloves for electrical purposes
60947 Low-voltage switchgear and controlgear
60947.2 Part 2: Circuit-breakers
62271 High-voltage switchgear and controlgear
62271.100 Part 100: High-voltage alternating-current circuit-breakers
62271.301 Part 301: Dimensional standardization of terminals
AS/NZS
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1270 Acoustics—Hearing protectors

2381 Electrical equipment for explosive gas atmospheres—Selection, installation and
maintenance
2381.1 Part 1: General requirements
3160 Approval and test specification—Hand-held portable electric tools
60598 Luminaires
60598.2.8 Part 2.8: Particular requirements—Handlamps
IEC
60480 Guidance for the checking and treatment of sulphur hexafluoride (SF6) taken
from electrical equipment and specification for its re-use

www.standards.org.au © Standards Australia

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AS 2467—2008
90

NOTES
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91

NOTES
AS 2467—2008
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AS 2467—2008
92

NOTES
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