IEC 62040-1-2:2002

INTERNATIONAL IEC
STANDARD
62040-1-2
First edition
2002-08
Uninterruptible power systems (UPS) –
Part 1-2:
General and safety requirements for UPS
used in restricted access locations
Alimentations sans interruption (ASI) –
Partie 1-2:
Prescriptions générales et règles de sécurité pour les ASI
utilisées dans des locaux d'accès restreint

Reference number
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60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1.

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edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the base publication, the
base publication incorporating amendment 1 and the base publication incorporating
amendments 1 and 2.
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INTERNATIONAL IEC
STANDARD
62040-1-2
First edition
2002-08
Uninterruptible power systems (UPS) –
Part 1-2:
General and safety requirements for UPS
used in restricted access locations
Alimentations sans interruption (ASI) –
Partie 1-2:
Prescriptions générales et règles de sécurité pour les ASI
utilisées dans des locaux d'accès restreint

 IEC 2002  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
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International Electrotechnical Commission
Международная Электротехническая Комиссия
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– 2 – 62040-1-2  IEC:2002(E)
CONTENTS
FOREWORD . 4

1 Scope and specific applications . 6

1.1 Scope . 6

1.2 Specific applications . 6

2 Normative references. 7

3 Definitions . 8

4 General requirements .11

4.1 UPS design and construction.11
4.2 User information .11
4.3 Classification of UPS .11
4.4 General conditions for tests .11
4.5 Operating parameters for tests .11
4.6 Loads for tests.12
4.7 Components .12
4.8 Power interfaces.12
4.9 Marking and instructions.12
5 Fundamental design requirements .17
5.1 Protection against electric shock and energy hazards.17
5.2 SELV .18
5.3 Emergency switching device.18
5.4 Backfeed protection.19
5.5 Insulation.19
5.6 Safety extra-low voltage (SELV) circuits .20
5.7 Limited current circuits.20
5.8 Provisions for protective earthing.20
5.9 AC and d.c. power isolation .20
5.10 Overcurrent and earth fault protection.21
5.11 Service person protection .22
5.12 Clearances, creepage distances and distances through insulation .23
5.13 External signalling circuits .23
5.14 Limited power source.23
6 Wiring, connections and supply.24

6.1 General .24
6.2 Connection to power sources.24
6.3 Wiring terminals for external power conductors.24
7 Physical requirements.25
7.1 Enclosure .25
7.2 Stability .26
7.3 Construction details .26
7.4 Resistance to fire.27
7.5 Battery location.27
7.6 Temperature rise .29
8 Electrical requirements and simulated abnormal conditions .29
8.1 General .29
8.2 Electric strength.30
8.3 Abnormal operating and fault conditions .30

62040-1-2  IEC:2002(E) – 3 –
Annexes………………………………………………………………………………………………. 32-43

Table 1 – Location of battery protective device(s) .22

Table 2 – Temperature-rise limits.29

Table 3 – Permitted temperature limits for magnetic windings
at the end of stored energy mode operation .29

Table H.1 – Degrees of protection against foreign objects indicated

by the first characteristic numeral.33

Table H.2 – Degrees of protection against water indicated by the second characteristic

numeral.34

Table P.1 − (extract from IEC 60439-1) .43

– 4 – 62040-1-2  IEC:2002(E)
UNINTERRUPTIBLE POWER SYSTEMS (UPS) –

Part 1-2: General and safety requirements for UPS

used in restricted access locations

FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote

international co–operation on all questions concerning standardization in the electrical and electronic fields. To

this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non–governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International
Organization for Standardization (ISO) in accordance with conditions determined by agreement between the
two organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62040-1-2 has been prepared by IEC technical committee 22H:
Uninterruptible power systems (UPS), of IEC technical committee 22: Power electronic
systems and equipment.
The text of this standard is based on the following documents:
FDIS Report on voting
22H/23/FDIS 22H/25/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.
Annexes L, M, N and P form an integral part of this standard.
Annex H is for information only.
In this standard, the following print types are used:
– Requirements proper and normative annexes: in roman type.
– Compliance statements and test specifications: in italic type.
– Notes and other informative matter: in smaller roman type.
– Normative conditions within tables: in smaller roman type.
− Terms that are defined in clause 3: bold

62040-1-2  IEC:2002(E) – 5 –
The committee has decided that this publication remains valid until 2006. At this date, in
accordance with the committee’s decision, the publication will be

• reconfirmed;
• withdrawn;
• replaced by a revised edition, or

• amended.
The contents of the corrigendum of December 2002 have been included in this copy.

– 6 – 62040-1-2  IEC:2002(E)
UNINTERRUPTIBLE POWER SYSTEMS (UPS) –

Part 1-2: General and safety requirements for UPS

used in restricted access locations

1 Scope and specific applications

1.1 Scope
This standard applies to electronic uninterruptible power systems with an electrical energy
storage device in the d.c. link. It is to be used with IEC 60950-1 which is referred to in this
standard as “RD”.
When any item is referred to by the phrase “The definitions or the provisions of item/RD
apply”, this phrase is intended to mean that the definitions or provisions in that item of
IEC 60950-1 apply, except any which are clearly inapplicable to uninterruptible power
systems. National requirements additional to those in IEC 60950-1 apply and are found as
notes under relevant clauses of the RD.
The primary function of the UPS covered by this standard is to ensure continuity of an
alternating power source. The UPS may also serve to improve the quality of the power source
by keeping it within specified characteristics.
This standard is applicable to UPS which are movable, stationary, fixed or for building-in, for
use on low-voltage distribution systems and intended to be installed in restricted access
locations. It specifies requirements to ensure safety for the service person.
This standard is intended to ensure the safety of installed UPS, both as a single UPS unit or
as a system of interconnected UPS units, subject to installing, operating and maintaining the
UPS in the manner prescribed by the manufacturer.
This standard does not cover d.c. supplied electronic ballasts (IEC 60924 and IEC 60925) and
UPS based on rotating machines.
The relevant general and safety requirements for UPS intended to be installed in operator
access areas are given in IEC 62040-1-1; electromagnetic compatibility (EMC) requirements
and definitions are given in IEC 62040-2.
1.2 Specific applications
Even if this standard does not cover all types of UPS, it may be taken as a guide for such
equipment. Requirements additional to those specified in this standard may be necessary for
specific applications, for example:
– UPS intended for operation while exposed, for example, to extremes of temperature; to
excessive dust, moisture, or vibration; to flammable gases; to corrosive or explosive
atmospheres;
– electromedical applications with the UPS located within 1,5 m from the patient contact
area;
– UPS subject to transient overvoltages exceeding those for Overvoltage Category II
according to IEC 60664, additional protection might be necessary in the mains supply to
the UPS.
– UPS intended for use where ingress of water and foreign objects are possible, additional
requirements may be necessary; for guidance on such requirements and for relevant
testing, see annex H.
62040-1-2  IEC:2002(E) – 7 –
– UPS with trapezoidal output waveforms and long run times (greater than 30 min) are

subject to voltage distortion tests for the purpose of load compatibility.

NOTE For UPS intended to be used in vehicles, on board ships or aircraft, in tropical countries, or on elevations
greater than 1 000 m, different requirements may be necessary.

2 Normative references
The following referenced documents are indispensable for the application of this document.

For dated references, only the edition cited applies. For undated references, the latest edition

of the referenced document (including any amendments) applies.

IEC 60364 (all parts), Electrical installations of buildings
IEC 60364-4-41:2001, Electrical installations of buildings – Part 4-41: Protection for safety –
Protection against electric shock
IEC 60364-4-482:1982, Electrical installations of buildings – Part 4: Protection for safety –
Chapter 48: Choice of protective measures as a function of external influences – Section 482:
Protection against fire
IEC 60417 (all parts), Graphical symbols for use on equipment
IEC 60439-1:1999, Low-voltage switchgear and controlgear assemblies – Part 1: Type-tested
and partially type-tested assemblies
IEC 60445:1999, Basic and safety principles for man–machine interface, marking and
identification – Identification of equipment terminals and of terminations of certain designated
conductors, including general rules for an alphanumeric system
IEC 60529:1989, Degrees of protection provided by enclosures (IP Code)
IEC 60950-1:2001, Safety of information technology equipment
IEC 61000-2-2:2002, Electromagnetic compatibility (EMC) – Part 2-2: Environment –
Compatibility levels for low-frequency conducted disturbances and signalling in public low-
voltage power supply systems
IEC 61140:2001, Protection against electric shock – Common aspects for installation
and equipment
IEC 62040-1-1: Uninterruptible Power Systems (UPS) – Part 1-1: General and safety
requirements for UPS used in operator access areas
IEC 62040-2:1999, Uninterruptible Power Systems (UPS) – Part 2: Electromagnetic
compatibility (EMC) requirements
IEC 62040-3: 1999, Uninterruptible Power Systems (UPS) – Part 3: Method of specifying
the performance and test requirements
___________
To be published
– 8 – 62040-1-2  IEC:2002(E)
3 Definitions
3.1 General
For the purpose of this standard, the following definitions apply. Where the terms “voltage”

and “current” are used, they imply the r.m.s. values, unless otherwise specified.

NOTE Care should be taken that measurement instruments give a true r.m.s. reading in the presence of non-

sinusoidal signals. For other terms and definitions, see also IEC 62040-3.

3.1.1
uninterruptible power system (UPS)
combination of convertors, switches and energy storage devices (for example, batteries),
constituting a power system for maintaining continuity of load power in case of input power
failure
3.1.2
continuity of load power
load power with voltage and frequency within rated steady-state and transient tolerance
bands and with distortion and interruptions within the limits specified for the load
3.1.3
bypass
power path alternative to the indirect a.c. converter
3.1.4
power failure
any variation in power supply which can cause unacceptable performance of the load
equipment
3.1.5
primary power
power supplied by an electrical utility company or by a user’s generator
3.1.6
active power
sum of the electrical power at the fundamental frequency and the powers of each harmonic
component from the output terminals, in W or kW
3.1.7
apparent power
product of the r.m.s. output voltage and r.m.s. current

3.1.8
rated voltage
input or output supply voltage (for three-phase supply, the phase-to-phase voltage) as
declared by the manufacturer
3.1.9
rated voltage range
input or output supply voltage range as declared by the manufacturer, expressed by its lower
and upper rated voltages
3.1.10
rated current
maximum input or output current of the UPS as declared by the manufacturer

62040-1-2  IEC:2002(E) – 9 –
3.1.11
backfeed
condition in which a voltage or energy available within the UPS is fed back to any of the input

terminals, either directly or by a leakage path while operating in the stored energy mode and

with primary power not available

3.2 Operating conditions
3.2.1
reference load
mode of operation which approximates as closely as possible to the most severe conditions of

normal use in accordance with the manufacturer's operating instructions; however, when the
conditions of actual use can obviously be more severe than the maximum load conditions
recommended by the manufacturer, a load shall be used that is representative of the
maximum that can be applied
NOTE For examples of reference load conditions for UPS, see annex M.
3.2.2
linear load
load where the current drawn from the supply is defined by the relationship:
I = U/Z
where
I is the load current;
U is the supply voltage;
Z is the load impedance.
3.2.3
non-linear load
load where the parameter Z (load impedance) is no longer a constant but is a variable
dependent on other parameters, such as voltage or time (see annex M)
3.2.4
stored energy mode
operation of the UPS when supplied by the following conditions:
– primary power is disconnected or is out of a given tolerance;
– battery is being discharged;
– load is within the given range;

– output voltage is within the given tolerance
3.3 Equipment mobility
The definitions of 1.2.3/RD apply.
3.4 Insulation classes of UPS
The definitions of 1.2.4/RD apply.
3.5 Connection to the supply
The definitions of 1.2.5/RD apply.
3.6 Enclosures
The definitions of 1.2.6/RD apply.

– 10 – 62040-1-2  IEC:2002(E)

3.7 Accessibility
The definitions of 1.2.7/RD apply.

3.8 Circuits and circuit characteristics

The definitions of 1.2.8/RD apply.

3.8.1
hazardous voltage
The definitions in 1.2.8.5/RD apply.

3.9 Insulation
The definitions of 1.2.9/RD apply.
3.10 Creepage distances and clearances
The definitions of 1.2.10/RD apply.
3.11 Components
The definitions of 1.2.11/RD apply.
3.12 Power distribution
The definitions of 1.2.8/RD apply.
3.13 Flammability
The definitions of 1.2.12/RD apply.
3.14 Miscellaneous
The definitions of 1.2.13.2/RD, 1.2.13.3/RD, 1.2.13.4/RD, 1.2.13.7/RD and 1.2.13.8/RD apply
together with the following.
3.14.1
type test
The definition of 1.4.2/RD apply together with the following addition.

Where in this standard compliance of materials, components or subassemblies is checked by
inspection or by testing of properties, it is permitted to confirm compliance by reviewing any
relevant data or previous test results that are available instead of carrying out the specified
type tests.
NOTE For physically large units and/or power ratings, adequate test facilities to demonstrate some of the type
tests may not exist.
This situation also applies to some electrical tests for which no commercial test simulation
equipment is available or requires specialized test facilities beyond the scope of the manu-
facturer's premises.
3.15 Telecommunication networks
The following definitions apply:
1.2.8.9/RD, 1.2.8.10/RD, 1.2.8.11/RD, 1.2.8.12/RD, 1.2.8.13/RD

62040-1-2  IEC:2002(E) – 11 –

4 General requirements
4.1 UPS design and construction

A UPS shall be so designed and constructed that, under conditions of normal use and likely

fault conditions, it protects against risks of personal injury from electric shock and other

hazards, and against serious fire originating in the UPS or connected loads, within the

meaning of this standard.
Where the UPS involves safety situations not specifically covered, the design should provide

a level of safety not less than that generally afforded by this standard.

Unless otherwise specified, compliance is checked by inspection and by carrying out all the
relevant tests.
NOTE The need for additional detailed requirements to cope with a new situation should be brought promptly to
the attention of the appropriate committee.
4.2 User information
Sufficient information shall be provided to the user concerning any condition necessary to
ensure that the UPS will not present a hazard within the meaning of this standard when used
as prescribed by the manufacturer (see 4.8).
Compliance is checked by inspection.
4.3 Classification of UPS
A UPS covered by this standard is classified according to its protection from electric shock as
Class I.
4.4 General conditions for tests
The provisions of 1.4.1/RD, 1.4.2/RD, 1.4.3/RD, 1.4.6/RD, 1.4.7/RD, 1.4.8/RD, 1.4.10/RD,
1.4.11/RD, 1.4.12/RD, 1.4.13/RD, 1.4.14/RD apply together with the following.
Only the leakage current and heating tests shall be performed at input voltage tolerances.
All other tests shall be run at nominal input voltages.
4.5 Operating parameters for tests
Except where specific test conditions are stated elsewhere in the standard, and where it is

clear that there is a significant impact on the results of the test, the tests shall be carried out
under the most unfavourable combination of the following parameters, within the manu-
facturer's operating specifications:
– supply voltage;
– absence of supply voltage;
– supply frequency;
– charge condition of the battery;
– physical location of UPS and position of movable parts;
– operating mode.
– 12 – 62040-1-2  IEC:2002(E)

4.6 Loads for tests
In determination of input current, and where other test results could be affected, the following

variables shall be considered and adjusted to give the most unfavourable results:

– loads due to recharging of batteries;

– loads due to optional features, offered or provided for by the manufacturer for inclusion in

or with the equipment under test;

– loads due to other units of equipment intended by the manufacturer to draw power from

the equipment under test.
Artificial loads may be used to simulate such loads during testing.
4.7 Components
The provisions of 1.5.1/RD, 1.5.2/RD, 1.5.4/RD, 1.5.5/RD, 1.5.6/RD, 1.5.7/RD, 1.5.8/RD apply.
4.8 Power interfaces
The provisions of 1.6.1/RD, 1.6.2/RD, 1.6.4/RD apply together with the following.
The neutral conductors, if any, shall be insulated from earth and the body throughout the
equipment, as if they were a phase conductor. Components connected between neutral and
earth shall be rated for a working voltage equal to the phase-to-neutral voltage. In the case
of the output neutral conductor being isolated from the input neutral conductor, the service
person responsible for the installation shall connect this output neutral conductor as required
by local wiring rules and as detailed in the installation instructions.
Compliance is checked by inspection.
4.9 Marking and instructions
4.9.1 General
The UPS shall be provided with a marking where it is required as detailed below. Provision
shall be allowed for equivalent wording. The marking shall be readily visible or shall be
located on an outside surface of the equipment. If located on an outside surface of fixed equip-
ment, the marking shall be visible after the equipment has been installed as in normal use.
Markings that are not visible from the outside of the equipment are considered to be in
compliance if they are directly visible when opening a door or cover.

4.9.2 Power rating
Equipment shall be provided with adequate markings in order to specify
– input supply requirements;
– output supply ratings.
For equipment with multiple rated voltages, the corresponding rated currents shall be
marked in such a way that the different current ratings are separated by a solidus (/) and the
relation between rated voltage and associated rated current appears distinctly.
Equipment with a rated voltage range shall be marked with either the maximum rated
current or with the current range.

62040-1-2  IEC:2002(E) – 13 –

The markings of input and output shall include those in the RD, in addition to the following:

–output rated voltage;
–output rated current or rated power in volt-amperes or active power in watts;

– output rated power factor, if less than unity, or active power and apparent power or

active power and rated current.

– number of output phases (1φ – 3φ) with or without neutral;

– output rated active power, in watts or kilowatts according to annex M;

– output rated apparent power in volt-amperes or kilovoltamperes according to annex M;

– maximum ambient operating temperature range (optional).
NOTE Compliance according to annex M.
For units designed with additional separate automatic bypass/maintenance bypass,
additional input a.c. supply, or external batteries, it shall be allowed that relevant supply
ratings be specified in the accompanying installation instructions. Where this is done, the
following instruction shall appear on or near the point of connection.
SEE INSTALLATION INSTRUCTIONS BEFORE
CONNECTING TO THE SUPPLY
If a unit is not provided with a means for direct connection to the supply mains, it need not be
marked with its rated current.
4.9.3 Safety instructions
The manufacturer shall specify in his document or catalogue the conditions, if any, for the
installation, operation and maintenance of the UPS.
Where UPS are designed for restricted access locations only (not meeting the requirements
for a fire enclosure as specified in 1.2.6.2/RD), the installation instructions shall clearly state
that the UPS only be installed in accordance with the requirements of IEC 60364-4-482 .
If necessary, the instructions for transport, installation and operation shall indicate the
measures that are of particular importance for the proper and correct installation,
commissioning and operation of the UPS.
Where necessary, the above documentation shall indicate the recommended extent and
frequency of maintenance.
If the circuitry is not obvious from the physical arrangement of the UPS, suitable information,
for example, wiring diagrams, shall be supplied.
If the use of the UPS on IT power systems requires additional components in the building
wiring installation, the safety instructions shall be so stated, as well as any requirements to
meet 5.3.
NOTE 1 Special precautions may be necessary, for example, for battery connection of the UPS equipment to the
supply and the interconnection of separate UPS units, if any.
NOTE 2 Where appropriate, installation instructions should include reference to national wiring rules.
For UPS units designed with additional separate automatic bypass or maintenance bypass,
additional input a.c. supply or external batteries, it shall be allowed for the relevant supply
ratings to be specified in the accompanying installation instruction. Where this is done, the
following instructions shall appear on or near the point of connection:
SEE INSTALLATION INSTRUCTIONS BEFORE CONNECTING TO THE SUPPLY

– 14 – 62040-1-2  IEC:2002(E)

The manufacturer shall provide the user with guidance on the level of competence necessary

to operate the UPS as
– operated only by personnel authorized to enter restricted access locations.

When the disconnect device for isolation of power is not incorporated in the UPS

(see 3.4.2/RD) the installation instructions shall state that

– for permanently connected UPS, an appropriate disconnect device shall be incorporated in

the fixed wiring;
– for pluggable UPS and when the plug is used as a disconnect, the socket-outlet shall be

installed adjacent to the UPS and shall be easily accessible.

For permanently connected UPS where automatic backfeed isolation is provided external to
the equipment, the instructions shall require the fitting by the user of a warning label on all
primary power isolators installed remote from the UPS area to warn electrical maintenance
personnel that the circuit feeds a UPS.
The warning label shall carry the following wording or equivalent.
ISOLATE UNINTERRUPTIBLE POWER SYSTEM (UPS)
BEFORE WORKING ON THIS CIRCUIT
4.9.4 Main voltage adjustment
The provisions of 1.7.4/RD apply.
4.9.5 Power outlets
Unless fully rated, a marking shall be placed in the vicinity to show the maximum load that is
permitted to be connected to each outlet.
4.9.6 Fuses
Marking shall be located on, or adjacent to, each fuseholder (or in another location provided
that it is obvious to which fuseholder the marking applies) giving the fuse rated current and,
where fuses of different voltage ratings could be fitted, the fuse active power. Alternatively,
this information shall be given in the user documentation.
Where fuses with special fusing characteristics such as time delay or breaking capacity are
necessary, the type shall be indicated.

4.9.7 Wiring terminals
The wiring terminal intended for connection of the protective conductor associated with the
supply wiring shall be indicated by the symbol
.
This symbol shall not be used for other earthing terminals.
NOTE This requirement is applicable to terminals for connection of a protective earthing conductor whether run
as an integral part of a power supply cord or with supply conductors.
Terminals intended exclusively for connection of the primary power neutral conductor, if any,
shall be marked by the capital letter N.
On three-phase UPS, terminals intended for connection of the power phase conductors shall
be marked in accordance with IEC 60445 or the relevant installation instructions defined by
the manufacturer.
62040-1-2  IEC:2002(E) – 15 –

On three-phase UPS, if incorrect phase rotation could cause overheating or other hazards,

terminals intended for connection of primary power phase conductors shall be marked in

such a way that, in conjunction with any installation instructions, the sequence of phase

rotation is unambiguous.
These indications shall not be placed on screws, or other parts which might be removed when

conductors are being connected.

4.9.8 Battery terminals
Terminals intended for connection to batteries shall indicate the polarity according to

IEC 60417.
4.9.9 Controls and indicators
The provisions of 1.7.8/RD apply.
4.9.10 Isolation of multiple power sources
The provisions of 1.7.9/RD apply.
4.9.11 IT power systems
The provisions of 1.7.10/RD apply.
4.9.12 Protection in building installation
The provisions of 5.3.1/RD apply.
NOTE Consideration should be given to national wiring rules, if any, regarding requirements for public networks
protection.
4.9.13 High leakage current
The provisions of 5.1/RD apply, together with the following:
For UPS intended for use as pluggable equipment type B or fixed installations, where the
earth leakage currents of the UPS and connected loads sum in the primary UPS protective
earth conductor exceeds or is likely to exceed the limits of 5.1/RD under any mode of
operation, the unit shall carry a warning label as required by 5.1/RD, and the installation
manual shall define the connection method to the primary power source.

4.9.14 Thermostats and other regulating devices
See 1.7.11/RD.
4.9.15 Language
The provisions of 1.7.12/RD apply.
4.9.16 Durability of markings
The provisions of 1.7.13/RD apply.
4.9.17 Removable parts
The provisions of 1.7.14/RD apply.

– 16 – 62040-1-2  IEC:2002(E)

4.9.18 Replaceable batteries
The provisions of 1.7.15/RD apply.

4.9.19 Operator access with a tool

The provisions of 1.7.16/RD apply.

4.9.20 Battery
External battery cabinets or battery compartments within the UPS shall be provided with the

following, clearly legible information in such a position as to be immediately seen by a

service person when servicing the UPS, in accordance with the requirements of 1.7.1/RD:
a) battery type (lead-acid, NiCd, etc.) and number of blocks or cells;
b) nominal voltage of total battery;
c) nominal capacity of total battery (optional);
d) warning label denoting an energy or electrical shock and chemical hazard and reference to
the maintenance handling and disposal requirements detailed in the following instructions.
Exception: Pluggable equipment type A UPS, supplied with integral batteries or with
separate battery cabinets, intended for location either under or over or alongside the UPS,
connected by plugs and sockets for operator installation, need only be fitted with the warning
label (see item d above) on the outside of the unit.
All other information shall be given in the users' instructions.
Instructions
a) Internally mounted battery:
– instructions shall carry sufficient information to enable the replacement of the battery
with a suitable recommended type;
– safety instructions to allow access by a service person shall be stated in the
installation/service handbook;
– if batteries are to be installed by a service person, instructions for interconnections
including terminal torques shall be provided.
The operator manual shall include the following instructions:
− Servicing of batteries should be performed or supervised by personnel knowledgeable
about batteries and the required precautions.
− When replacing batteries, replace with the same type and number of batteries or

battery packs.
CAUTION: Do not dispose of batteries in a fire. The batteries may explode.
CAUTION: Do not open or mutilate batteries. Released electrolyte is harmful to the
skin and eyes. It may be toxic.
b) Externally mounted batteries:
– installation instructions shall state voltage, ampere-hour rating, charging regime and
method of protection required on installation to coordinate with UPS protective
devices, where the battery is not provided by the UPS manufacturer;
– instructions for the battery cells shall be provided by the battery manufacturer.

62040-1-2  IEC:2002(E) – 17 –

c) External battery cabinets:
External battery cabinets supplied with the UPS shall have adequate installation

instructions to define cable sizes for connection to the UPS if the cabling is not supplied

by the UPS manufacturer. Where the battery cells or blocks are not supplied, pre-installed

and wired, installation instructions for the battery cells or blocks shall be provided by the

battery manufacturer, if not detailed in the UPS manufacturer's installation instructions.

4.9.21 Signalling circuits
Adequate information shall be provided in the installation instructions as to the purpose and

connection of any signalling circuits, relay contacts, emergency shutdown circuits, etc.

Attention should be drawn as to the necessity of maintaining security of any SELV circuit
when connected to other equipment.
4.9.22 Internal circuit configuration
Installation instructions shall carry sufficient information, including the basic internal circuit
configuration of the UPS, to emphasize its compatibility to power distribution systems
(see 3.12).
Special attention shall be given to the compatibility with the relevant wiring rules and to
bypass circuits.
Where a UPS output neutral relies on the input supply/supplies neutral reference, adequate
installation instructions shall be provided to prevent loss of this neutral reference, if a hazard
should result due to external isolation/changeover of supply sources, etc.
Only UPS complying with the marking instruction of 1.7.10/RD are suitable for use on IT
power systems, as defined in 1.2.12.3/RD. Where additional external components are
required to meet this requirement, these shall be referenced in the installation instructions.
5 Fundamental design requirements
5.1 Protection against electric shock and energy hazards
The provisions of 2.1.1.4/RD, 2.1.1.6/RD, and 2.1.1.7/RD apply together with the following.
The UPS shall be designed and constructed to meet the appropriate requirements for
protection from electric shock, in accordance with the relevant clauses of IEC 61140. As an
installation, it shall comply with the relevant requirements of IEC 60364.

The UPS shall be constructed in such a way as to be capable of withstanding the thermal and
dynamic stresses resulting from short-circuit currents up to rated values.
NOTE The short-circuit stresses may be reduced by the use of current limiting devices (inductors, current limiting
fuses and other current limiting switching devices).
The UPS shall be protected against short-circuit currents by means of, for example, circuit
breakers, fuses or combination of both, which may be incorporated in the UPS or arranged
outside of it.
Compliance is checked by inspection and, if necessary, by test.
Protection from electric shock for the enclosure shall be tested with a test finger as in
figure 2A/RD which shall not contact live parts at hazardous voltage when applied to
apertures and components in the outside of the enclosure in its normal operating condition
unless these are placed out of reach (for example, at a height above 2 m).

– 18 – 62040-1-2  IEC:2002(E)

Apertures preventing entry of the test finger of figure 2A/RD are further tested by means of a

straight finger applied with a force of 30 N. If this finger enters, the test with figure 2A/RD is

repeated, the finger being pushed through the aperture if necessary.

UPS intended for building-in and/or rack mounting or for incorporation in larger equipment is

tested with access to UPS limited according to the method of mounting detailed by the

manufacturer.
5.2 SELV
Control and signalling circuits intended to be connected to other equipment in operator

access areas and which are operator accessible shall meet the requirements of 2.2/RD and
2.10/RD.
NOTE The definition of SELV circuit in 1.2.8.6/RD differs from the term SELV as used in IEC 60364-4-41.
Compliance is checked by inspection and, if necessary, test.
Control and signalling circuits that are not operator accessible shall meet the requirements
for SELV in IEC 60364-4-41 unless the manufacturer elects to meet 2.2/RD requirements for
all control and signalling circuits connections.
The manufacturer shall clearly state in his instructions the necessary separation of these
circuits in the wiring of the installation external to the UPS.
Compliance is checked by inspection and, if necessary, test.
UPS shall be so designed that at external points of disconnection of the supplies, there is no
risk of electric shock from stored charge on capacitors connected to the external circuit.
Compliance is checked by inspection of the UPS and relevant circuit diagrams, taking into
account the possibility of disconnection of the supplies with the ON/OFF switch in either
position.
UPS shall be considered to comply if any capacitor having a rated capacitance exceeding
0,1 μf and connected to the external mains circuit has a means of discharge resulting in a
time-constant not exceeding
– 10 s for permanently connected UPS and for pluggable UPS Type B.
NOTE 1 The relevant time-constant is the product of the effective capacitance in microfarads and the effective
discharge resistance in megohms. Where it is difficult to determine the effective resistance and capacitance
values, a measurement of voltage decay may be used. In one time-constant the voltage will have decayed to 37 %

of its original value.
NOTE 2 Attention is drawn to the fact that when loads are connected to the UPS, for certain configurations, the
risk of electric shock is not only due to the internal capacitors of the UPS but also to the capacitors of the load
connected to the UPS; this should be taken into account when des
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