TANZANIA ELECTRIC SUPPLY COMPANY LIMITED

“We Light Up Your Life”

SPECIFICATION S29

LV FUSE CUTOUTS AND FUSE LINKS

JULY, 2011.

TANZANIA ELECTRIC SUPPLY COMPANY LIMITED

Umeme Park, Morogoro Road - Ubungo,

P.O. Box 9024, Dar es Salaam, Tanzania.

Telephone: +255-22-2451130; 2451149; 2451133

Facsimile: +255-22-2451149; 2451133

 PART 1: GENERAL

1. SCOPE ............................................................................................................................. 1

2. STANDARDS .................................................................................................................. 1

3. SERVICE CONDITIONS.............................................................................................. 3

4. SYSTEM CONDITIONS ............................................................................................... 4

5. INSPECTION, TESTING AND QUALITY ASSURANCE....................................... 5

5.1 Inspection .......................................................................................................................... 5

5.2 Testing .............................................................................................................................. 5
5.3 Quality Assurance.............................................................................................................. 6

6. SPARE PARTS ............................................................................................................... 7

7. PACKING AND SHIPPING.......................................................................................... 7

7.1 Packing .............................................................................................................................. 7

7.2 Shipping............................................................................................................................. 8
7.3 Hazardous Substances ....................................................................................................... 9

8. SUBMITTALS ............................................................................................................... 9

8.1 Submittals Required With the Bid...................................................................................... 9

8.2 Submittals Required by TANESCO After Contract Award............................................. 10

PART 2: TECHNICAL

9. GENERAL...................................................................................................................... 12

10. RATINGS ....................................................................................................................... 13

11. HOUSING....................................................................................................................... 13

12. FUSE CARRIER............................................................................................................ 14

13. COVER ........................................................................................................................... 14

14. TERMINALS ................................................................................................................. 15

15. MATERIALS ................................................................................................................. 15

16. MARKINGS................................................................................................................... 16

17. TESTS ............................................................................................................................. 16

17.1 Temperature Rise Test...................................................................................................... 17

17.2 Test of Dielectric Properties ............................................................................................ 17
17.3 Wet Voltage Withstand Test............................................................................................. 17
17.4 Making and Breaking Capacities Test............................................................................... 17
17.5 Short Time Current Withstand Test.................................................................................. 18
17.6 Mechanical Endurance Test.............................................................................................. 18
17.7 Electrical Endurance Test ................................................................................................. 18
17.8 Impact Strength Test ........................................................................................................ 18
17.9 Flame Retardation Test..................................................................................................... 18

18. GUARANTEE................................................................................................................ 19

19. SCHEDULES ................................................................................................................. 20

19.1 Technical Data Schedule: LV Fuse Cutout....................................................................... 20

19.2 Technical Data Schedule: Fuse Link................................................................................. 22
19.3 Non Compliance Schedule................................................................................................ 23
19.4 Test Certificates Schedule................................................................................................. 24

PART 3: INSTALLATION

20. INSTALLATION ........................................................................................................... 25

APPENDICES

Figure 1 : Low Voltage J.P Cartridge Fuse Link 26

TABLES

Table 1 : Sequence of events in flame retardation test 19

 Specification S29 - LV Fuse Cutouts

PART 1: GENERAL

1. SCOPE

This specification covers the design, manufacture, testing, supply, and delivery and
performance requirements of LV Fuse Cutouts and Cartridge Fuse Links for use in the
networks of the Tanzania Electric Supply Company Limited.

Any departure from the provisions of this specification shall be disclosed at the time of
tendering in the Non compliance schedule, in part 2 of this document.

2. STANDARDS

The equipment shall comply with the latest editions of, and amendments to, the
international standards listed below. Where any provision of this specification differs from
those of the standards listed below, the provisions of this specification shall apply:

BSI British Standards Institution:

 BS 88-1: Cartridge fuses for voltages up to and including 1000 V a.c. and 1500 V
d.c.: Part 1: Specification of general requirements.

 BS 88-5: Cartridge fuses for voltages up to and including 1000 V a.c. and 1500 V
d.c.: Part 5: Specification of supplementary requirements for fuse-links for use in
a.c. electricity supply networks.

 BS 729: Specification for hot dip galvanized coatings on iron and steel articles.

 BS 3643: ISO metric screw threads.

 BS 4190: Specification for ISO metric black hexagon bolts, screws and nuts.

European Union Commission:

 SI 426: European Communities (dangerous substances) (classification, packaging,
labelling and notification) regulation, 1992.

IEC International Electrotechnical Commission:

 IEC 947-3: Low-voltage switchgear and controlgear. Part 3: Switches

disconnectors, switch-disconnectors and fuse-combination units.

ISO International Organization for Standardization:

 ISO 9000: Quality management and quality assurance standards - Guidelines for
selection and use.

 ISO 14000: Environmental Management

S29-1
 Specification S29 - LV Fuse Cutouts

Associated specifications:

 S01: General technical requirements of 33kV, 11kV and LV networks.

 S11: Wood poles.

 S11A: Concrete poles
 S11B: Steel poles

 S13: Crossarms and associated steelwork.

 S17: Aerial bundled conductors.

 S21: Distribution pole mounted transformers.

 S35: Bolts, nuts and washers.

 S54: 33kV/11kV/LV distribution power cables.

The bidder may propose alternative standards, provided it is demonstrated that they give a
degree of quality and performance equivalent to that of the referenced standards.
Acceptability of any alternative standard is at the discretion of TANESCO. Therefore, the
bidder must quote for the main standard.

3. SERVICE CONDITIONS

The service conditions shall be as follows:

 Altitude (above sea level) 1,600m

 Maximum outdoor temperature 40C

 Minimum outdoor temperature 10C

 Maximum monthly mean temperature 35C

 Annual mean temperature 22C

 Maximum relative humidity 60% to 96%

 Isokeraunic level tropical

 Maximum wind velocity 58km/h

 Prevailing wind direction SE and NW

 Type of atmosphere coastal

Environmentally, the region where the work will take place is a coastal area, subject to an

S29-2
 Specification S29 - LV Fuse Cutouts

overall medium relative humidity, which can give rise to condensation. Onshore winds are
frequently salt laden. On occasions, the combination of salt and condensation may create
pollution conditions for outdoor insulators.

Therefore, outdoor material and equipment shall be designed and protected for use in an
exposed, polluted, salty, corrosive and humid coastal atmosphere.

Indoor material and equipment shall be designed and protected for use in buildings, which
occasionally may be wet and damp.

4. SYSTEM CONDITIONS

The equipment shall be suitable for installation in supply systems of the following
characteristics:

 Frequency 50Hz

 Nominal system voltages 33kV

11kV
400/230V

 Maximum system voltages: 33kV 36kV

11kV 12kV

 Maximum LV voltage 440/253V

 Minimum LV voltage 374/215V

 Nominal short circuit levels: 33kV 25kA

11kV 25kA
LV 7.5kA
 Insulation levels:

1.2/50s impulse (positive and

negative polarity): 33kV 170kV
11kV 75kV

 Power frequency (one minute

withstand, wet): 33kV 70kV
11kV 28kV
LV 3kV

 Neutral earthing arrangements: 33kV effectively earthed

11kV effectively earthed
LV effectively earthed

 Creepage distance 30mm/kV

(of maximum system voltage)

S29-3
 Specification S29 - LV Fuse Cutouts

5. INSPECTION, TESTING AND QUALITY ASSURANCE

5.1 Inspection

The Supplier/Manufacturer shall submit a detailed programme covering the design,

manufacture and testing of the equipment within one month of receipt of the contract
award.

Reports shall subsequently be submitted at intervals, outlining progress and, if necessary,

explaining deviations from the programme.

The TANESCO representatives shall have free entry at all times, while work on the
contract is being performed, to all parts of the manufacturer's works which concern the
processing of the equipment ordered. The manufacturer shall afford the TANESCO
representative, without charge, all reasonable facilities to satisfy himself or herself that the
equipment being furnished is in accordance with this specification.

LV cutouts will be inspected during delivery, and TANESCO reserves the right to reject
ALL or PART of the delivered LV cutouts if they will be found that they do not comply
with this specification.

5.2 Testing

The equipment shall successfully pass all the type tests and routine tests referred to in part
2 and those listed in the most recent edition of the standards given in clause 2 of this
specification.

TANESCO’s representatives reserve the right to reject an item of equipment if the test
results do not comply with the values specified or with the data given in the technical data
schedule.

Type tests shall be carried out at an independent testing laboratory or be witnessed by a

representative of such laboratory or some other representative acceptable to TANESCO.
Routine tests shall be carried out at the manufacturer's works.

Type tests may be dispensed with at the TANESCO's discretion if the manufacturer
furnishes evidence to the TANESCO’s satisfaction that the relevant tests have already been
performed on identical equipment. In this case test certificates shall be submitted with the
bid for evaluation.

TANESCO shall have the tests witnessed by a representative. In order to facilitate this, the
Supplier/Manufacturer shall give TANESCO a minimum of four weeks notice that the
equipment is ready for testing. If TANESCO does not indicate her intention to participate
in the testing, the manufacturer shall carry out the tests and shall furnish the results thereof
to TANESCO.

Full details of the proposed methods of testing, including connection diagrams, shall be
submitted to TANESCO by the Supplier/Manufacturer for approval, at least one month
before testing.

S29-4
 Specification S29 - LV Fuse Cutouts

All costs in connection with the testing shall be borne by the manufacturer who shall
provide TANESCO’s representatives with all the test facilities which the latter may require,
free of charge. TANESCO’s representative shall have the right to select the samples if he
or she so desires and shall also have the right to satisfy himself or herself that the testing
apparatus is correct.

The supplier/manufacturer shall submit to TANESCO’s representatives, five signed copies

of the test certificates, giving the results of the tests as required. No materials shall be
dispatched until TANESCO has received the test certificates and the Supplier/Manufacture
has been informed that they are acceptable.

The test certificates must show the actual values obtained from the tests, in the units used
in this specification, and not merely confirm that the requirements have been met.

TANESCO’s representative shall have the equipment inspected after reception and he or
she shall have the right to select the samples if desired for further test. The supplier shall
cooperate with this inspection and shall provide TANESCO’s representative, free of
charge, all the facilities which the latter may require.

In the case of components for which specific type tests or routine tests are not called for in
part 2 or in the quoted standards in clause 2 of this specification, TANESCO’s
representative shall include a list of all tests he or she proposes the manufacturer to carry
out.

5.3 Quality Assurance

The contractor shall provide current certification showing the manufacturer's compliance
with ISO 9000 or equivalent national standard.
6. SPARE PARTS

The bid shall include, if any a comprehensive list of all consumable and non consumable
spare parts and accessories, necessary for five years of normal operation as specified by the
manufacturer.

In addition, the bid shall include, if any in price schedule of these Bidding documents, a
price list of recommended non consumable spare parts for all major items of equipment.

The bidder shall give an assurance that spare parts will continue to be available through the
life of the equipment.

The spare parts shall be clearly identified and related to the specific equipment item. Spare
parts shall be delivered suitably packed and treated for long periods in storage. Each pack
shall be clearly and indelibly marked with its contents, including a designation number
corresponding to the spare parts list in the operation and maintenance instructions.

S29-5
 Specification S29 - LV Fuse Cutouts

7. PACKING AND SHIPPING

7.1 Packing

All equipment, including accessories, shall be packed and securely clamped against
movement in robust, wooden, non returnable packing cases to ensure safe transit from the
manufacturer's works to the work sites.

The packing shall provide suitable protection against all climatic conditions prevailing
during transport and on site.

Equipment or material liable to deterioration by sea water, moisture, or ingress of foreign

matter shall be totally sealed in strong polythene bags.

All accessories shall be carefully packed so that they are fully protected during transport
and handling operations and in storage.

Internal surfaces of loose accessories shall be sealed off by means of gaskets and blanking
off plates. Equipment and surfaces liable to deterioration due to condensation shall be
protected by packs of silica gel or other approved desiccant.

Each packing case shall be indelibly marked, in two adjacent sides and on the top, with the
following:

 Individual serial number;

 Client's name, that is Tanzania Electric Supply Company Limited;
 Contract number;
 Contractor's name;
 Name and address of contractor's agent in Tanzania;
 Manufacturer's name;
 Description of contents;
 Country of origin;
 Case measurements;
 Gross and net weights in kilogrammes; and
 All necessary slinging and stacking instructions.

Each case shall contain a fully detailed packing list in a sealed waterproof envelope.

Five copies of each packing list shall be sent to TANESCO prior to dispatching the
equipment.

7.2 Shipping

The supplier shall be responsible for the shipping of all plant and equipment supplied from
abroad to the ports of entry and for the transport of all goods to TANESCO designated
Stores and for all the costs and expenses resulting from it in accordance with INCOTERM
specified.

S29-6
 Specification S29 - LV Fuse Cutouts

All transport accessories, such as riding lugs, jacking pads, blanking off plates, etc. shall
become the property of TANESCO.

All items of equipment shall be securely clamped against movement to ensure safe transit
from the manufacturer's facilities to the work sites.
All accessories shall be carefully packed so that they are fully protected during transport
and handling operations and while in storage.

The supplier shall advise, if requested, the storage required for any plant and equipment
that may be delivered to the TANESCO designated stores. The supplier shall be required
to accept responsibility for the advice given, in so far as these arrangements may have a
bearing on the behaviour of the equipment in subsequent service.

7.3 Hazardous Substances

The contractor shall submit safety data sheets for all substances used with the equipment.
These substances shall be classified in accordance with the European Union SI 426:
European Communities (dangerous substances) (classification, packaging, labelling and
notification) regulation, 1992, or any subsequent amendment.

The contractor shall give an assurance that there are no other substances classified as
hazardous in the equipment supplied. The contractor shall accept responsibility for the
disposal of such hazardous substances, should any be found.

The contractor shall also be responsible for any injury resulting from hazardous substances.

8. SUBMITTALS

In addition to the documentation set out in specification S01: General technical

requirements of 33kV, 11kV and LV networks, some technical documentation is required
as set out in clauses 8.1 and 8.2 below:

8.1 Submittals Required With the Bid

The following shall be required:

 Completed technical data schedule;

 General description of the equipment and all components, including original

brochures;

 Outline dimension drawing for each major component and general arrangement
drawing showing component layout;

 Drawing showing the mounting arrangement of the LV fuse cutouts with a 3 phase
transformer mounted on a H pole structure, for a two LV service, a three LV
service and a four LV service configuration;

 Information on the pre-arcing characteristics of each fuse rating offered;

S29-7
 Specification S29 - LV Fuse Cutouts

 Time-current characteristics for each fuse rating offered;

 A short description of the manufacturing process;

 Safety data sheets for all substances used with the equipment;

 Certified original type test certificates and sample routine test reports with an
address of the Independent laboratory that undertook the type test. Uncertified
reports shall be rejected henceforth the bid will be non responsive.
 Detailed reference list of customers including their address, telephone & fax
numbers, e-mail address, etc already using equipment offered with particular
emphasis on units of similar design and rating;

 Details of manufacturer's quality assurance standards and programme; and

 Deviations from this specification. Only deviations approved in writing before

award of contract shall be accepted.

 Samples of the LV cutouts.

8.2 Submittals Required by TANESCO After Contract Award

The following shall be required:

 Drawing of cutout for technical verification & approval;

 Programme for production and testing;

 Detailed assembly instructions within each packing case for each transformer
cutout;

 A training video illustrating installation, operation and maintenance of the plant

item; and

 Two bound folders and two electronic copies preferably Compact Discs (CDs)
with records of the technical particulars relating to the equipment. Each shall
contain the following information:
- Descriptive literature giving full technical details of equipment offered;
- Technical data schedule, with approved revisions;
- detailed dimension drawing for all components and general arrangement
drawing showing detailed component layout;
- Statement drawing attention to all exposed points in the equipment at
which aluminium or aluminium alloy parts are in contact with or in close
proximity to other metals and stating clearly what protection is employed at
each point to exclude air and moisture;
- Inspection and test reports of tests carried out in the manufacturer's works
in both hard copy and electronic copy preferably in a compact disk
(CD);

S29-8
 Specification S29 - LV Fuse Cutouts

- Detailed installation and commissioning instructions, including the step by

step installation procedures, torque values and conductor preparation
measures;
- Operation and maintenance instructions specifying correct operational
procedures where appropriate; and
- Trouble shooting charts.

S29-9
 Specification S29 - LV Fuse Cutouts

PART 2: TECHNICAL

9. GENERAL

This specification covers the design, manufacture, testing, supply, delivery and
performance requirements of pole mounted fuse combination units, comprising

 The base assembly, including cable entries and terminals; and

 The cover which shall normally house the fuses or solid links and which shall be
used to operate the LV fuse cutout.

The fuse combination units shall be used to protect distribution pole mounted
transformers and distribution ground mounted transformers connected to overhead
networks and feeding into an overhead system of the type described in specification S01:
General technical requirements of 33kV, 11kV and LV networks.

In this specification, a pole mounted fuse combination unit is defined as a shrouded

apparatus designed for operation from ground level and for use as a fuse unit, a linking
switch or a short circuiting device.

The cutout shall be suitable for mounting on a wood pole or on the vertical surface of an
auxiliary crossarm in a transformer pole, with three cutouts per crossarm.

All items shall be free from defects, which could cause them to be incorrectly assembled or
to perform unsatisfactorily in service. The finish shall be such that outer surfaces are free of
sharp edges and burrs, which could result in damage to adjacent material or personnel.

Items comprising different component parts shall be so designed that they can be applied
without disassembly. The installation of all items shall be possible by one man working
alone.

10. RATINGS
The cutout bases and fuse carriers shall have the following current ratings at 230/400V:

 Three phase and neutral for transformers up to 500kVA: 400A; and

 Three phase and neutral for transformers above 500kVA: 630A.

All items of the LV fuse cutout shall be designed to meet the performance requirements of
the various clauses of this specification. They shall be adequately rated for their intended
application and retain this rating during their normal lifetime in an outdoor environment.

Thermal performance shall be in accordance with BS 88-1 and BS 88-5. All metal parts
shall be non ferrous. Arcing tips shall be provided to safeguard the fuse when it is removed
from a live circuit. To facilitate maintenance the design shall be such that when the fuse
carrier is withdrawn a minimum number of parts remain connected to the incoming
conductors.

S29-10
 Specification S29 - LV Fuse Cutouts

11. HOUSING

The outer housing of the units shall be comprised of grey insulating material of sufficient
mechanical strength as to prevent it from becoming damaged. The material shall be
resistant to ultra violet degradation and have flame retardant properties. The grey colour
shall be RAL 7035 code system according to DNA (German Standards Board,
Frankfurt, Germany).

The material shall be Lexan 943A unreinforced polycarbonate or any cast resin approved
by TANESCO.

12. FUSE CARRIER

The fuse carrier shall be required to take J.P. type cartridge fuse links with 82mm centres,
conforming to BS 88. Tightening screws shall have insulated tops to enable the fuse carrier to
be removed without safety devices (rubber gloves, etc.).

13. FUSE LINKS

The cartridge fuse link shall comprise insulating container, extinguishing medium, fuse
element, end caps, enclosing the tube ends and anchoring the fuse element and end tags
attached to the outside of the end caps and electrically connected to the element. The fuse
links supplied shall be of a type equivalent to the English Electric J.P. Type fuse with
82mm between centres.

Fuse links shall be required to give satisfactory performance for voltages up to 440V. The
rated current of the fuse link shall be carried continuously without deterioration of the
current carrying parts. Fuse links with the following current ratings are standard in the
TANESCO's networks:

 80A;
 160A;
 200A;
 250A; and
 400A.

The fuse link shall be suitable for use with the fuse cutout described in this specification,
both from the dimensional and from heat dissipation points of view. The maximum values
of power dissipation shall be in conformity with BS 88-5.

The rated breaking capacity of the fuse link shall be 80kA as per BS 88-5. The pre arcing
characteristic for each fuse rating offered and the operating time-current characteristic for
each fuse rating offered shall be given with the bid.

Figure 1 shows a typical outline of a low voltage J.P. type cartridge fuse link.

S29-11
 Specification S29 - LV Fuse Cutouts

14. COVER

The cover or lid of the units shall be suitable for normal operations and for removal and
refitting using one hand.

The cover shall be capable of withstanding a vertical load of 5kg even when in the closed
unloaded position.

15. TERMINALS

The cutout shall facilitate cable entry from the bottom with the fuse carrier also being
withdrawn downwards by opening the cover of the cutout.

The maximum cable size which will require to be accommodated is 185sq mm, having the
following physical dimensions:

 Diameter over conductor: 18mm;

 Diameter over insulation: 27mm; and
 Connector bore: 20mm.

The cutout terminals shall be of the pillar type, with sharply serrated contours to take
stranded aluminium as well as copper cables.

Protection of the terminals from weathering shall be provided by means of guarding sheds
and the application of sufficient sealant grease in the terminal bores.

The connector surface finishing material shall be tin. The preparation and treatment,
including tin analysis, quality of application and thickness shall be arranged and supervised
so that the resulting surface finish will give outdoor protection for 25 years. The
connector tightening bolts shall consist of silicon bronze. Special tools shall not be
required for tightening up the connectors.

Sealing and insulating greases at the conductor terminals shall be stable and neutral with
respect to the adjacent insulating and conducting materials and it shall not migrate nor drip
at temperatures below 150C.

15. MATERIALS

The materials used for manufacturing the apparatus covered by this specification shall be
compatible with the materials of the PVC insulated power cables so that the reliability of
the apparatus and the cable shall not be impaired by their association.

Materials shall be resistant to climatic stress. All insulating materials shall be stabilized to
ultraviolet light and shall be coloured grey. Steel parts shall be hot dip galvanised to BS
729 and other metallic parts shall be of the non-corrosive type. Non metallic materials shall
be fire retardant.

All threaded parts shall be manufactured to ISO metric standard BS 3643 and hexagonal
heads and nuts shall be made in conformity with ISO metric standard BS 4190.

S29-12
 Specification S29 - LV Fuse Cutouts

16. MARKINGS

The fuse cutouts shall be legibly and indelibly marked with the manufacturers name or
logo, in accordance with IEC 947-3; and the words

Property of

Where items are suitable for use on a range of conductor sizes, the largest and smallest size
of the range shall be displayed.

17. TESTS

The cartridge fuse links shall be tested in accordance with BS 88-1 and BS 88-5 or
equivalent. At least the following tests shall be conducted:

 Verification of rated power dissipation of fuse links: these tests shall be carried
out in accordance with BS 88-1 and the maximum values at the rated currents shall
be in accordance with BS 88-5;

 Verification of time-current characteristics: this test shall be performed in

accordance with BS 88-1. The verified points on the plotted time-current
characteristic shall not deviate by more than 10% in terms of current from the
manufacturer's curves and shall lie within the standard zones as given in the
relevant graphs in BS 88-5; and verification of conventional non fusing current
and conventional fusing current: this test shall be in accordance with BS 88-1.

The performance characteristics of the LV fuse cutouts themselves shall be verified by

successful completion of the range of tests listed below. In order to complete the tests, all
fittings and accessories comprising the fuse and load break system shall be required (that is:
fuse transition pieces, solid links, etc.).

17.1 Temperature Rise Test

The unit shall be erected as in the service condition with normal 400A cartridge fuse fitted
to the 400A unit and a 630A cartridge fuse to the 630A unit. Air movement of up to 0.6
metres per second shall be permitted in the region of the test unit. The test shall be carried
out generally in accordance with the method contained in IEC 947-3 and the results shall
meet the requirements of that standard.

17.2 Test of Dielectric Properties

This test shall be carried out on the unit which has just completed the temperature rise test
after the temperature has returned to ambient (+ 5C). The test method is as described in
IEC 947-3. A 4kV, 50Hz voltage shall be maintained for one minute without flashover.

17.3 Wet Voltage Withstand Test

This test shall be carried out after the LV fuse cutout has satisfactorily completed the

S29-13
 Specification S29 - LV Fuse Cutouts

dielectric properties test. A 50Hz, 4kV, voltage shall be applied between phase and neutral
poles. Artificial rain shall be directed onto the unit at 45 and falling at a rate of 3mm per
minute (the specific resistance of water shall be 10,000 ohms/cub cm). No flashover shall
occur within five minutes but a glow is acceptable.

17.4 Making and Breaking Capacities Test

The unit shall be erected as in the service condition with solid links fitted. The test method
and requirements shall be in accordance with utilisation category 21-B, as defined in table
II of IEC 947-3.

17.5 Short Time Current Withstand Test

This test is intended to prove the satisfactory operation of the short circuit device and fuse
cutout contacts. The unit shall be mounted with the short circuit device in position. In
accordance with IEC 947-3, five current pulses are applied. The value of these alternating
current pulses shall be 20 times full load current for 1 second. The requirements shall be
those of IEC 947-3.

17.6 Mechanical Endurance Test

The unit shall be mounted as it will be in service and shall be operated without presence of
voltage or current. Three thousand operations shall be performed in the conditions
specified in IEC 947-3 and the requirements shall be those stated in the same standard.

17.7 Electrical Endurance Test

The unit shall be mounted as it will be in service and shall be operated by hand. One
hundred and fifty operations shall be performed on the energised units in the conditions
specified in IEC 947-3 and the requirements shall be those stated in the same standard.

17.8 Impact Strength Test

A weight of 0.25kg shall be dropped from a height of 0.2m onto a selected surface area of
the unit under test. The height of the drop shall be increased by increments of 0.05m until
break or failure occurs, and that height shall be recorded.

The test shall be considered to have passed if no break or failure occurs at or before a
height of 2m.

17.9 Flame Retardation Test

A single hole 30mm diameter shall be made in the test material. A gas torch shall be lit and
adjusted to produce a yellow flame.

This flame shall be applied to the area around the hole in the sequence shown below. The
results shall be no worse than those listed in the sequence of events column:

S29-14
 Specification S29 - LV Fuse Cutouts

Time Sequence of Events

(Hrs)
0:00 Gas flame applied and maintained
0:30 No noticeable burning of material
1:00 Heat source removed. No combustion takes place
5:00 Gas flame applied and maintained
6:00 Minor blackening of surrounding materials and hairline cracks occurring
7:00 Minimum smoke and gasses noted
8:00 Heat source removed. The material self extinguishes immediately
8:15 No appreciable overheating occurred around the area under influence of
heat source

Table 1: Sequence of events in flame retardation test

18. GUARANTEE

All cutouts and fuselinks shall be guaranteed in writing, against all defects arising from
faults in design, material and workmanship. The guarantee period shall not be less than
twelve (12) months from commissioning date or eighteen (18) months from the delivery
date.

This period shall be extended to five (5) years to cover all defects attributed to
inadequate corrosion protection.

Should any design fault become apparent to TANESCO after the expire of the above
guarantee periods, the manufacturer in collaboration with his local agent shall deliver
components necessary to correct the faults, together with any necessary instructions and
specialist assistance, free of charge.

S29-15
 Specification S29 - LV Fuse Cutouts

19. SCHEDULES

19.1 Technical Data Schedule: LV Fuse Cutouts

Description Unit TANESCO Bid
Type, Code or Model of LV Fuse Cutout
Manufacturer
Country of Origin
Catalogue number
International standard it complies with
Rated frequency Hz
Maximum rated voltage kV
Rated current A
Short time rated current kA
Rated interruption capacity kA
Fuse links rated currents compatible to the Cutout A
Temp. rise at continuous rated current 
Type of conductors suitable for
Type and grade of housing material sq mm
Type of terminals
Type and grade of terminal materials
Type of finish in terminals
Type and grade of terminal grease 
Drop point in grease
Type of sealing at conductor entries
Type of fuse cartridges
Is short circuit device provided? (y/n)
Is earthing device provided? (y/n)
Are incoming and outgoing cable entries marked
inside and outside? (y/n)
Surfaces in which it can be mounted
Type of tool needed to tighten terminals
Colour
Dimensions: width mm
depth mm
height mm
Weight kg
Guarantee period months
NB: Please fill one schedule for each type or model of LV fuse cutout

S29-16
 Specification S29 - LV Fuse Cutouts

19.2 Technical Data Schedule : Fuse Links

Description Unit TANESCO Bid

Type of Fuse Link
Manufacturer
Country of Origin
Catalogue number
International standard it complies with
Rated frequency Hz
Rated current (Specify offered ones only) A
Rated Voltage V
Rated Breaking Capacity at 415V a.c kA
Current de-rating at 1,600m altitude %
Max/Min melting current : 0.1s A
10s A
300s/600s A
o
Max temperature with rated current and C
40 oC ambient temperature
Tensile breaking load N
Composition of fuse links
Composition of fuse element
Fuse links fixing centers mm
Fuse links marking – indicate all
Does the fuse links have an ASTA or other
(specify) certification (y/n)

S29-17
 Specification S29 - LV Fuse Cutouts

19.3 Non Compliance Schedule

On this schedule the bidder shall provide a list of non compliances with this specification,
documenting the effects that such non compliance is likely to have on the equipment's life
and operating characteristics. Each non compliance shall be referred to the relevant
specification clause.

Clause No Non Compliance

S29-18
 Specification S29 - LV Fuse Cutouts

19.4 Test Certificates Schedule

On this schedule a list of the test certificates included with the bid shall be provided. This
list shall include type test certificates and samples of routine test reports. Each certificate
listed shall be referred to the relevant specification clause.

Clause No Type Test Certificate or Routine Test Report

S29-19
 Specification S29 - LV Fuse Cutouts

PART 3: INSTALLATION

20. INSTALLATION

TANESCO’s employees shall do the installation work of LV fuse cut outs unless
otherwise stated. General guidelines for installation work involved are given in specification
S01: General technical requirements of 33kV, 11kV and LV networks.

S29-20
 Specification S29 - LV Fuse Cutouts

Figure 1: Low Voltage J.P Type Cartridge Fuse Link

S29-21