AS 3011.

2—1992

Australian Standard

Electrical installations
Secondary batteries installed in
buildings
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Part 2: Sealed cells

 This Australian Standard was prepared by Committee EL/5, Secondary Batteries. It
was approved on behalf of the Council of Standards Australia on 23 December 1991
and published on 16 March 1992.

The following interests are represented on Committee EL/5:

Australian Automobile Association

Australian Automotive Aftermarket Association
Australian Electrical and Electronic Manufacturers Association
Australian Federation of Consumer Organizations
Australian Lead Development Association
Confederation of Australian Industry
Department of Defence
Electricity Supply Association of Australia
Federal Chamber of Automotive Industries
Institution of Engineers, Australia
Railways of Australia
Telecom Australia

Additional interest participating in preparation of Standard:

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Civil Aviation Authority

Review of Australian Standards. To keep abreast of progress in industry, Australian Standards are subject
to periodic review and are kept up to date by the issue of amendments or new editi ons as necessary. It is
important therefore that Standards users ensure that they are in possession of the latest editi on, and any
amendments thereto.
Full detail s of all Australi an Standards and related publications wil l be found in the Standards Australia
Catalogue of Publications; this information is supplemented each month by the magazine ‘The Australi an
Standard’, which subscribing members receive, and which gives details of new publications, new editi ons
and amendments, and of withdrawn Standards.
Suggesti ons for improvements to Australian Standards, addressed to the head offi ce of Standards Australi a,
are welcomed. Noti fi cati on of any inaccuracy or ambiguity found in an Australi an Standard should be made
without delay in order that the matter may be investigated and appropriate action taken.

This Standard was issued in draft form for comment as DR 90091.

 AS 3011.2—1992

Australian Standard

Electrical installations
Secondary batteries installed in
buildings
Part 2: Sealed cells
Accessed by HOLMESGLEN INSTITUTE on 27 Jul 2017 (Document currency not guaranteed when printed)

First publi shed as AS 3011.2 1992.

PUBLISHED BY STANDARDS AUSTRALIA

(STANDARDS ASSOCIATION OF AUSTRALIA)
1 THE CRESCENT, HOMEBUSH, NSW 2140
ISBN 0 7262 7301 5
 AS 3011.2—1992 2

PREFACE

This Standard was prepared by the Standards Australia Committee on Secondary

Batteries. It is a statement of minimum requirements and is intended to be suitable for
reference in government regulations.
Over the last few years both the ampere-hour capacity and voltage of battery
installations have increased to the point where some voltages now border on the
medium and high voltage range. Even in extra-low voltage installations, the low
internal resistances of batteries under short-circuit conditions can cause severe injuries
to staff working on a battery or cell, or cause fire and explosion.
Recent tests have shown that batteries of 30 V and above may present problems in
breaking fault currents and that additional precautions need to be taken to reduce the
possibility of accidental short-circuits.
In preparing this Standard, the Committee considered the requirements of both sealed
lead-acid cells and sealed alkaline cells.

CONTENTS
Page

SECTION 1 SCOPE AND GENERAL

1.1 SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 REFERENCED DOCUMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
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1.3 DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

SECTION 2 GENERAL REQUIREMENTS

2.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 BATTERY ROOM REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . 5
2.3 BATTERY ENCLOSURE REQUIREMENTS . . . . . . . . . . . . . . . . . 6

SECTION 3 INSTALLATION

3.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2 CONNECTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.3 PROTECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

APPENDIX A TYPICAL BATTERY ROOM LAYOUT

(SHOWING MINIMUM CLEARANCES) . . . . . . . . . . . . . . 8

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 3 AS 3011.2—1992

STANDARDS AUSTRALIA

Australian Standard
Electrical installations — Secondary batteries installed in buildings

Part 2: Sealed cells

SECTION 1 SCOPE AND GENERAL

1.1 SCOPE This Standard sets out requirements for the installation of sealed secondary batteries with a nominal
voltage exceeding 24 V and a capacity exceeding 10 A.h at the 1 h rate of discharge, permanently installed in
or on buildings, structures or premises to ensure safety from fire and electric shock.
AS 2676.2 provides guidance on the installation and maintenance of sealed secondary batteries.
This Standard covers sealed cells only. The installation and maintenance of vented cells are covered by AS 3011.1
and AS 2676.1.
NOTE: Requir ements specif ically appli cable to the design and install ation of extra-l ow voltage (d.c.) power supplies that are used by
telecommunications carri ers in the provision of public telecommunications networks are given in AS 3015 (Int) —1991, Electri cal
installati ons — Extra-l ow volt age (d.c.) power suppli es in publi c telecommunications networks.
1.2 REFERENCED DOCUMENTS The following documents are referred to in this Standard:
AS
1136 Low voltage switchgear and controlgear assemblies
1136.1 Part 1: General requirements
1680 Interior lighting
1680.1 Part 1: General principles and recommendations
1775 Low voltage switchgear and controlgear — Air-break switches, isolators and fuse-combination units
(up to and including 1000 V a.c. and 1200 V d.c.)
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2676 Guide to the installation, maintenance, testing and replacement of secondary batteries in buildings
2676.1 Part 1: Vented cells
2676.2 Part 2: Sealed cells
3000 SAA Wiring Rules
3011 Electrical installations — Secondary batteries installed in buildings
3011.1 Part 1: Vented cells
1.3 DEFINITIONS For the purpose of this Standard, the definitions below apply.
1.3.1 Accessible, readily — capable of being reached quickly and without climbing over or removing
obstructions, mounting upon a chair, or using a movable ladder, and in any case not more than 2 m above the
ground, floor or platform.
1.3.2 Authorized person — the person in charge of the premises, or other person appointed or selected by the
person in charge of the premises, who performs certain duties associated with the battery installation on the
premises.
NOTE: In some states, work on low and medium voltage equipment may be undert aken by li censed personnel only.
1.3.3 Battery — a unit consisting of one or more cells connected in a series, parallel or series-parallel
arrangement to supply the voltage and current requirements of a connected load.
1.3.4 Battery enclosure — an enclosure containing batteries that is suitable for use in an area other than a
battery room or an area restricted to authorized personnel.
1.3.5 Battery room — a room specifically intended for the installation of batteries.
1.3.6 Cell — an assembly of electrodes and electrolytes which constitutes the basic unit of a battery.
1.3.7 Charging — an operation during which a battery receives electric energy, which is converted to chemical
energy, from an external circuit. The quantity of electric energy is known as the charge.
NOTE: Charge is usuall y measured in ampere hours.
1.3.8 Horizontally mounted cell — a cell designed to operate with its terminals and valves mounted on a
vertical face (see Figure 1(a)).
1.3.9 May — indicates the existence of an option.
1.3.10 Monobloc battery — a secondary battery in which two or more cells are fitted in a multi-compartment
container.

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 AS 3011.2—1992 4

1.3.11 Nominal voltage — a stated value of voltage used to identify a type of cell. For the purpose of this
Standard, the nominal voltage of a lead-acid cell is 2 V and that of a nickel-cadmium cell is 1.2 V.

1.3.12 Sealed gastight cell — a cell which remains closed and does not release either gas or liquid when
operated within the limits of charge and temperature specified by the manufacturer. The cell may be equipped
with a safety device to prevent dangerously high internal pressure. The cell does not require addition to the
electrolyte and is designed to operate during its life in its original sealed state.

1.3.13 Sealed valve-regulated cell — a cell which is closed under normal conditions but which has an
arrangement which allows the escape of gas if the internal pressure exceeds a predetermined value. Electrolyte
is not normally added to a sealed value-regulated cell.

1.3.14 Shall — indicates that a statement is mandatory.

1.3.15 Should — indicates a recommendation.

1.3.16 Vertically mounted cell — a cell designed to operate with its terminals and valves mounted on its upper
horizontal surface (see Figure 1(b)).
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FIGU RE 1 CELL TERMINOLOGY

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 5 AS 3011.2—1992

SECTION 2 GENERAL REQUIREMENTS

2.1 GENERAL
2.1.1 Hydrogen emission When on float charge in accordance with the manufacturer’s instructions, a sealed
cell will not emit significant amounts of hydrogen but when subject to abnormal charging conditions a sealed cell
will emit hydrogen. Suitable means to prevent overcurrent or overvoltage in excess of the battery manufacturer’s
recommendations shall be incorporated into the charger control.
2.1.2 Alarms An alarm shall be initiated indicating an overcurrent or overvoltage condition or alternatively the
battery charger shall automatically shut down if an overcurrent or overvoltage condition occurs.
NOTE: Recommendations on alarms are given in AS 2676.2.
2.1.3 Battery accommodation A battery shall be installed in one of the following:
(a) A battery room in accordance with Clause 2.2.
(b) An enclosure in accordance with Clause 2.3.
(c) An area restricted to authorized personnel.
An enclosure shall take the form of a cabinet with lockable doors, a covering box or other suitable housing which
shall be lockable and provide protection against electrical contact or damage to the battery.
2.1.4 Arrangement of cells The space between cell containers shall be at least 3 mm regardless of the
arrangement of cells used. Each cell shall be readily accessible for testing, cleaning or removal as applicable.
Each cell shall be accessible without having to reach over another cell; alternatively, all exposed live surfaces
shall be shrouded.
2.1.5 Ventilation The average hydrogen concentration by volume in a battery room or enclosure shall be
maintained below 2%. AS 2676.2 provides guidance on the calculation of airflow required and on the
arrangement of ventilation equipment.
If mechanical ventilation is installed, an airflow sensor shall be incorporated to initiate an alarm should the
ventilation fan be inoperative.
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2.2 BATTERY ROOM REQUIREMENTS

2.2.1 General The battery room shall be located so that access to a battery is not obstructed by the structure
of the building or by the fixtures and fittings within the building.
Direct current distribution boards, rotary machinery other than exhaust fans, and other equipment not directly part
of the battery and charging facilities shall —
(a) be located outside the battery room; or
(b) have no exposed live parts.

2.2.2 Battery room layout and floor area The battery room layout and floor area shall meet the following
requirements (see Appendix A, Figure A1):
(a) If more than one battery is installed in a battery room, either —
(i) all batteries shall have all live surfaces insulated or shrouded; or
(ii) all potential differences between exposed live parts exceeding 120 V d.c. shall be separated by
1800 mm (measured in a straight line).
(b) The floor area shall allow for the following clearances:
(i) Aisle width The minimum aisle width shall be 900 mm. A greater aisle width may be necessary in
installations requiring the use of mechanical handling equipment for battery maintenance.
(ii) Single-row battery In addition to the minimum aisle width, there shall be a minimum of 25 mm
clearance between a cell and any wall or structure on a side not requiring access for maintenance. This
does not preclude battery stands touching adjacent walls or structures, provided that the battery shelves
have free air space for no less than 90% of their length.
(iii) Double-row battery A double-row battery may be installed in accordance with Item (ii) for single row
batteries provided all live surfaces are insulated or shrouded.
If the battery has exposed live surfaces, the minimum aisle width shall be maintained on one end and
both sides of the battery. The other end of the battery shall have a minimum clearance of 25 mm
between any wall or structure and a cell.
(iv) Tiered battery A tiered battery shall comply with Items (i), (ii) and (iii). If the battery has its cells
mounted vertically, the minimum vertical clearance between any part of a cell and any part of the tier
above shall be half the distance to the rearmost terminal of the battery or 75 mm, whichever is the
greater. The vertical clearance need not exceed 200 m (see Appendix A, Figure A2).

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 AS 3011.2—1992 6

If the battery has its cells mounted horizontally, there shall be a clearance between any part of a cell
and any part of the tier above. The clearance shall be in accordance with the manufacturer’s
specification or, if unspecified, shall be 50 mm.
(v) Battery chargers If a battery charger or other associated electrical equipment is located in a battery
room, the aisle width between a battery and any part of the battery-charging equipment (including the
doors when fully open) shall be at least 900 mm.

2.2.3 Take-off battery terminals and outgoing busbars and cables Outgoing busbars and cables shall —
(a) be insulated, from the battery terminals to a height of 3.75 m or the battery room ceiling, whichever is the
lower; and
(b) be clearly identified and segregated from any other supply circuits.
Take-off battery terminals and busbar connections shall —
(i) be shrouded or be protected by insulating barriers to prevent accidental contact; and
(ii) have their polarity clearly identified. Connectors between monobloc batteries need not have polarity
identification.

2.2.4 Inter-tier and inter-row connections The battery terminals and busbar and cable inter-connections
between inter-row and inter-tier terminals shall be either —
(a) shrouded; or
(b) protected by insulating barriers to prevent accidental contact.

2.2.5 Inter-cell connectors To avoid accidental contact with inter-cell connectors, a battery shall have all live
surfaces insulated or shrouded, or the following insulating barriers shall be fitted:
(a) Double-row battery Insulating barriers shall be installed between rows for the entire length of the battery
and shall extend 100 mm past the end terminals unless those terminals are shrouded (see Appendix A,
Figure A1).
The barrier shall extend vertically a minimum of 400 mm above the exposed portion of the inter-cell
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connections and a minimum of 25 mm below the top of the battery container.

(b) Battery voltage exceeding 120 V Where the nominal voltage of a battery exceeds 120 V, interblock barriers
shall be installed to sectionalize the battery into voltage blocks not exceeding 120 V (see Appendix A,
Figure A1).
Barriers shall extend a minimum of 50 mm out from the exposed side of the battery and a minimum of
400 mm above the top of the container.

2.2.6 Luminaires Battery room lighting shall be installed in accordance with AS 1680.1. Luminaires shall be
installed in the middle of aisles and at a minimum distance of 200 mm from any part of a battery. Luminaires
shall not be installed directly over a cell or an exposed live part.

2.2.7 Location of general purpose outlets General purpose outlets shall be located at least 1800 mm from the
battery and a minimum of 100 mm below the lowest point of the highest ventilation opening.

2.3 BATTERY ENCLOSURE REQUIREMENTS

2.3.1 Enclosure construction Where enclosures are designed to accommodate a battery, the battery charger and
other equipment, a separate compartment shall be provided for the battery. The ventilation openings for the
compartments shall be spaced as far apart as possible.

2.3.2 Take-off battery terminals and outgoing busbars and cables Outgoing busbars and cables shall be fully
insulated. Take-off battery terminals and busbar connections shall —
(a) be shrouded or be protected by insulating barriers to prevent accidental contact; and
(b) have their polarity clearly identified.

2.3.3 Battery compartment circuits Only circuits associated with a battery shall be installed within a battery
compartment of an enclosure.

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 7 AS 3011.2—1992

SECTION 3 INSTALLATION
3.1 GENERAL The design of a battery installation shall take into consideration the prospective short-circuit
current of the battery as nominated by the battery manufacturer. In particular this applies to the connection from
the battery to the main d.c. switchboard or associated equipment. The installation shall comply with AS 3000.

3.2 CONNECTIONS A battery and any solid busbar system shall be connected by an insulated flexible
connection of suitable current rating. Flexible cables may be terminated directly on the battery terminals.

3.3 PROTECTION
3.3.1 Overcurrent protection The output conductors of a battery shall be protected against overcurrent by a
fuse or circuit-breaker in at least one output conductor. A battery which does not have either output conductor
connected to earth shall be provided with a fuse or circuit-breaker in each output conductor.
A rewireable fuse shall not be used for this purpose. Protective equipment shall not be located in the battery
compartment of an enclosure.

3.3.2 Warning notices If the capacity of a battery exceeds 100 A.h, at the 3 h rate of discharge, or if the
nominal battery voltage is in excess of extra-low voltage, suitable warning notices indicating the battery voltage
and the prospective short-circuit current of the installation shall be displayed.

3.3.3 Switchgear Any d.c. switchgear or controlgear associated with a battery installation shall comply with the
appropriate requirements of AS 1775. If the prospective short-circuit current at the switchgear is in excess of 20
kA, the switchboard shall be compartmented and shall incorporate explosion venting to comply with AS 1136.1.

3.3.4 Earth-leakage detection If a battery is unearthed, is of nominal voltage greater than 120 V and is supplied
from a battery charger using an isolating transformer, an earth-leakage detector shall be provided to initiate an
earth-leakage alarm.

3.3.5 Main isolating switch A battery installation shall have an isolating switch installed as close as practicable
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to the main terminals of the battery. If a busway system is installed, the isolating switch may be incorporated into
the end of the busway.

3.3.6 Section isolating equipment If the battery voltage exceeds 120 V, the installation shall be fitted with
isolating switches, plugs or links to separate the battery into sections of less than 120 V for maintenance. Suitably
identified inter-cell connectors, for example, with insulation of a different colour to other inter-cell connectors
may be used for this purpose.
NOTE: It is intended that the isolati ng swit ch, plugs or li nks should be used only for major maintenance of a battery, such as removal
or replacement of cell s, or corrosion repair, to provide protection from electr ic shock to operators.

3.3.7 Fire safety and warning signs Regulatory authorities may have requirements for fire safety and warning
signs.

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 AS 3011.2—1992 8

APPENDIX A

TYPICAL BATTERY ROOM LAYOUT (SHOWING MINIMUM CLEARANCES)

(Normative)
(Layout based on unshrouded live surfaces)
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O = Terminal DIMENSIONS IN MILLIMETRES

FIGU RE A1 BA TTER Y ROOM LAYO UT

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 9 AS 3011.2—1992

FIGU RE A2 VER TICA L CLEA RA NC E FOR VER TICA LLY

MOUN TED TIER ED BATTERIES
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