EN IEC 62040-1:2019

SLOVENSKI STANDARD
01-november-2019
Nadomešča:
SIST EN 62040-1:2009
SIST EN 62040-1:2009/A1:2013
Sistemi z neprekinjenim napajanjem (UPS) - 1. del: Varnostne zahteve (IEC 62040-
1:2017)
Uninterruptible power systems (UPS) - Part 1: Safety requirements (IEC 62040-1:2017)
Unterbrechungsfreie Stromversorgungssysteme (USV) - Teil 1: Allgemeine
Anforderungen und Sicherheitsanforderungen (IEC 62040-1:2017)
Alimentations sans interruption (ASI) - Partie 1: Exigences de sécurité (IEC 62040-
1:2017)
Ta slovenski standard je istoveten z: EN IEC 62040-1:2019
ICS:
29.200 Usmerniki. Pretvorniki. Rectifiers. Convertors.
Stabilizirano električno Stabilized power supply
napajanje
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 62040-1

NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2019
ICS 29.200 Supersedes EN 62040-1:2008 and all of its amendments
and corrigenda (if any)
English Version
Uninterruptible power systems (UPS) - Part 1: Safety
requirements
(IEC 62040-1:2017)
Alimentations sans interruption (ASI) - Partie 1: Exigences Unterbrechungsfreie Stromversorgungssysteme (USV) -
de sécurité Teil 1: Sicherheitsanforderungen
(IEC 62040-1:2017) (IEC 62040-1:2017)
This European Standard was approved by CENELEC on 2017-08-16. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 62040-1:2019 E

European foreword
The text of document 22H/217/FDIS, future edition 2 of IEC 62040-1, prepared by SC 22H
"Uninterruptible power systems (UPS)" of IEC/TC 22 "Power electronic systems and equipment" was
submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN IEC 62040-1:2019.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2020-01-19
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2022-07-19
document have to be withdrawn
This document supersedes EN 62040-1:2008 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CENELEC by the European
Commission and the European Free Trade Association.
Endorsement notice
The text of the International Standard IEC 62040-1:2017 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 60076-11:2004 NOTE Harmonized as EN 60076-11:2004 (not modified)
IEC 60364-5-52 NOTE Harmonized as HD 60364-5-52
IEC 60947-1:2007 NOTE Harmonized as EN 60947-1:2007 (not modified)
IEC 60947-3:2008 NOTE Harmonized as EN 60947-3:2009 (not modified)
IEC 60947-6-1:2005 NOTE Harmonized as EN 60947-6-1:2005 (not modified)
IEC 60947-6-1:2005/A1:2013 NOTE Harmonized as EN 60947-6-1:2005/A1:2014 (not modified)
IEC 61347 (series) NOTE Harmonized as EN 61347 (series)
IEC 61439-1:2011 NOTE Harmonized as EN 61439-1:2011 (not modified)
IEC 61508 (series) NOTE Harmonized as EN 61508 (series)
IEC 62040-3:2011 NOTE Harmonized as EN 62040-3:2011 (not modified)
IEC 62310-1 NOTE Harmonized as EN 62310-1
IEC 62368-1:2014 NOTE Harmonized as EN 62368-1:2014/AC:2015 (not modified)

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60364-4-42 - Low-voltage electrical installations - Part 4-HD 60364-4-42 -
(mod) 42: Protection for safety - Protection
against thermal effects
IEC 60384-14 - Fixed capacitors for use in electronic EN 60384-14 -
equipment - Part 14: Sectional
specification - Fixed capacitors for
electromagnetic interference suppression
and connection to the supply mains
IEC/TR 60755 - General requirements for residual current - -
operated protective devices
IEC 60947-2 2006 Low-voltage switchgear and controlgear - EN 60947-2 2006
Part 2: Circuit-breakers
IEC 60950-1 (mod) 2005 Information technology equipment - Safety EN 60950-1 2006
- Part 1: General requirements
+ A11 2009
+ A12 2011
IEC 61000-2-2 2002 Electromagnetic compatibility (EMC) - PartE N 61000-2-2 2002
2-2: Environment - Compatibility levels for
low-frequency conducted disturbances and
signalling in public low-voltage power
supply systems
IEC 61008-1 (mod) - Residual current operated circuit-breakers EN 61008-1 -
without integral overcurrent protection for
household and similar uses (RCCBs) - Part
1: General rules
IEC 61009-1 (mod) - Residual current operated circuit-breakers EN 61009-1 -
with integral overcurrent protection for
household and similar uses (RCBOs) - Part
1: General rules
IEC 62040-2 2005 Uninterruptible power systems (UPS) -- EN 62040-2 2006
Part 2: Electromagnetic compatibility
(EMC) requirements
Publication Year Title EN/HD Year
IEC 62477-1 2012 Safety requirements for power electronic EN 62477-1 2012
converter systems and equipment - Part 1:
General
IEC 62040-1 ®
Edition 2.0 2017-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Uninterruptible power systems (UPS) –

Part 1: Safety requirements
Alimentations sans interruption (ASI) –

Partie 1: Exigences de sécurité

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.200 ISBN 978-2-8322-4469-2

– 2 – IEC 62040-1:2017 © IEC 2017
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Protection against hazards . 15
5 Test requirements . 28
6 Information and marking requirements . 42
Annexes . 49
Annex A (normative) Additional information for protection against electric shock . 50
Annex M (informative) Test probes for determining access . 51
Annex AA (informative) Minimum and maximum cross-section of copper conductors

suitable for connection to terminals for external conductor . 52
Annex BB (normative) Reference loads . 53
Annex CC (normative) Ventilation of lead-acid battery compartments . 57
Annex DD (informative) Guidance for disconnection of batteries during shipment . 60
Annex EE (informative) Short-time withstand current test procedure – Guidance and
typical values . 62
Annex FF (informative) Maximum heating effect in transformer tests. 66
Annex GG (normative) Requirements for the mounting means of rack-mounted
equipment . 68
Bibliography . 70

Figure 101 – Examples of design of openings preventing vertical access . 18
Figure 102 – Test circuit for load-induced change of reference potential – Single-
phase output . 34
Figure 103 – Test circuit for load-induced change of reference potential – Three-phase
output . 34
Figure 104 – Voltage backfeed warning label . 45
Figure M.101 – Jointed test finger (IP2X) . 51
Figure BB.1 – Reference resistive load . 53
Figure BB.2 – Reference inductive-resistive load (series) . 54
Figure BB.3 – Reference inductive-resistive load (parallel) . 54
Figure BB.4 – Reference capacitive-resistive load (series) . 54
Figure BB.5 – Reference capacitive-resistive load (parallel) . 54
Figure BB.6 – Reference non-linear load . 55
Figure DD.1 – Precautionary label for products shipped with the battery disconnected . 60
Figure DD.2 – Precautionary label for products shipped with the battery connected . 61
Figure EE.1 – 3-wire test circuit for UPS short-time withstand current . 62
Figure EE.2 – 4-wire test circuit for UPS short-time withstand current . 63
Figure EE.3 – 2-wire test circuit for single phase UPS short-time withstand current . 64

Table 1 – Alphabetical list of terms . 9

IEC 62040-1:2017 © IEC 2017 – 3 –
Table 101 – UPS input port configuration . 16
Table 102 – Overvoltage categories . 19
Table 103 – Maximum temperature limits for magnetic components during stored
energy mode of operation . 21
Table 22 – Test overview . 29
Table 104 – Short-time withstand current . 37
Table 105 – Temperature limits for transformer windings . 40
Table A.101 – Comparison of limits of working voltage . 50
Table AA.1 – Conductor cross-sections (extract from IEC 61439-1:2011) . 52
Table FF.1 – Test steps . 66

– 4 – IEC 62040-1:2017 © IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
UNINTERRUPTIBLE POWER SYSTEMS (UPS) –

Part 1: Safety requirements
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of 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, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC
Publication(s)"). 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. 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 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 IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62040-1 has been prepared by subcommittee 22H: Uninterruptible
power systems (UPS), of IEC technical committee 22: Power electronic systems and
equipment.
This second edition cancels and replaces the first edition published in 2008 and its
Amendment 1:2013. This edition constitutes a technical revision.
This edition includes the following significant technical change with respect to the previous
edition: the reference document has been changed from IEC 60950-1:2005 (safety for IT
equipment) to IEC 62477-1 (group safety standard for power electronic converters).

IEC 62040-1:2017 © IEC 2017 – 5 –
The text of this International Standard is based on the following documents:
FDIS Report on voting
22H/217/FDIS 22H/218/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
This International Standard is to be read in conjunction with IEC 62477-1:2012.
The provisions of the general rules dealt within IEC 62477-1:2012 are only applicable to this
document insofar as they are specifically cited. Clauses and subclauses of IEC 62477-1:2012
that are applicable in this document are identified by reference to IEC 62477-1:2012, for
example, "Clause 4 of IEC 62477-1:2012 applies, except as follows".
The exceptions are then listed. The exceptions can take the form of a deletion, a replacement
or an addition of subclauses, tables, figures or annexes.
Subclauses, tables and figures that are additional to those in IEC 62477-1:2012 are, in this
document, identified by a suffix in the format of X.10x, for example 4.3.101.
Annexes that are additional to those in IEC 62477-1:2012 are, in this document, lettered AA,
BB, etc.
In this document, the following print types are used:
• requirements and normative annexes: roman type
• compliance statements and test specifications: italic type
• notes and other informative matter: smaller roman type
• normative conditions within tables: smaller roman type
• terms that are defined in Clause 3: bold
A list of all parts in the IEC 62040 series, published under the general title Uninterruptible
Power Systems (UPS), can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 6 – IEC 62040-1:2017 © IEC 2017
INTRODUCTION
IEC technical sub-committee 22H: Uninterruptible power systems (UPS) carefully considered
the relevance of each paragraph of IEC 62477-1:2012 in UPS applications. This part of
IEC 62040 utilizes IEC 62477-1:2012 as a reference document and references, adds,
replaces or modifies requirements as relevant. This is because product-specific topics not
covered by the reference document are the responsibility of the technical committee using the
reference document.
IEC 62477-1:2012 relates to products that include power electronic converters, with a rated
system voltage not exceeding 1 000 V AC or 1 500 V DC. It specifies requirements to
reduce risks of fire, electric shock, thermal, energy and mechanical hazards, except
functional safety as defined in IEC 61508 (all parts). The objectives of this document are to
establish a common terminology and basis for the safety requirements of products that
contain power electronic converters across several IEC technical committees.
IEC 62477-1:2012 was developed with the intention:
• to be used as a reference document for product committees inside IEC technical
committee 22: Power electronic systems and equipment in the development of product
standards for power electronic converter systems and equipment;
• to replace IEC 62103 as a product family standard providing minimum requirements for
safety aspects of power electronic converter systems and equipment in apparatus for
which no product standard exists; and
NOTE The scope of IEC 62103 contains reliability aspects, which are not covered by this document.
• to be used as a reference document for product committees outside TC 22 in the
development of product standards of power electronic converter systems and equipment
intended for renewable energy sources. TC 82, TC 88, TC 105 and TC 114, in particular,
have been identified as relevant technical committees at the time of publication.
The reference document, being a group safety standard, will not take precedence over this
product-specific standard according to IEC Guide 104. IEC Guide 104 provides information
about the responsibility of product committees to use group safety standards for the
development of their own product standards.

IEC 62040-1:2017 © IEC 2017 – 7 –
UNINTERRUPTIBLE POWER SYSTEMS (UPS) –

Part 1: Safety requirements
1 Scope
This part of IEC 62040 applies to movable, stationary, fixed or built-in UPS for use in low-
voltage distribution systems and that are intended to be installed in an area accessible by an
ordinary person or in a restricted access area as applicable, that deliver fixed frequency AC
output voltage with port voltages not exceeding 1 000 V AC or 1 500 V DC and that include an
energy storage device. It applies to pluggable and to permanently connected UPS, whether
consisting of a system of interconnected units or of independent units, subject to installing,
operating and maintaining the UPS in the manner prescribed by the manufacturer.
NOTE 1 Typical UPS configurations, including voltage and/or frequency converters and other topologies, are
described in IEC 62040-3, the test and performance product standard for UPS.
NOTE 2 UPS generally connect to their energy storage device through a DC link. A chemical battery is used
throughout the standard as an example of an energy storage device. Alternative devices exist, and as such, where
"battery" appears in the text of this document, this is to be understood as "energy storage device".
This document specifies requirements to ensure safety for the ordinary person who comes
into contact with the UPS and, where specifically stated, for the skilled person. The objective
is to reduce risks of fire, electric shock, thermal, energy and mechanical hazards during use
and operation and, where specifically stated, during service and maintenance.
This product standard is harmonized with the applicable parts of group safety publication
IEC 62477-1:2012 for power electronic converter systems and contains additional
requirements relevant to UPS.
This document does not cover:
• UPS that have a DC output;
• systems for operation on moving platforms including, but not limited to, aircrafts, ships
and motor vehicles;
• external AC or DC input and output distribution boards covered by their specific product
standard;
• stand-alone static transfer systems (STS) covered by IEC 62310-1;
• systems wherein the output voltage is directly derived from a rotating machine;
• telecommunications apparatus other than UPS for such apparatus;
• functional safety aspects covered by IEC 61508 (all parts).
NOTE 3 Even if this document does not cover the applications listed above, it is commonly taken as a guide for
such applications.
NOTE 4 Specialized UPS applications are generally governed by additional requirements covered elsewhere, for
example UPS for medical applications.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements 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.
– 8 – IEC 62040-1:2017 © IEC 2017
Clause 2 of IEC 62477-1:2012 applies, except as follows:
Add the following normative references:
IEC 60364-4-42, Low-voltage electrical installations – Part 4-42: Protection for safety –
Protection against thermal effects
IEC 60384-14, Fixed capacitors for use in electronic equipment – Part 14: Sectional
specification – Fixed capacitors for electromagnetic interference suppression and connection
to the supply mains
IEC TR 60755, General requirements for residual current operated protective devices
IEC 60947-2:2006, Low-voltage switchgear and controlgear – Part 2: Circuit-breakers
IEC 60950-1:2005, Information technology equipment – Safety – Part 1: General requirements
IEC 61000-2-2:2002, Electromagnetic compatibility (EMC) – Part 2-2: Environment –
Compatibility levels for low-frequency conducted disturbances and signaling in public low-
voltage power supply systems
IEC 61008-1, Residual current operated circuit-breakers without integral overcurrent
protection for household and similar uses (RCCBs) – Part 1: General rules
IEC 61009-1, Residual current operated circuit-breakers with integral overcurrent protection
for household and similar uses (RCBOs) – Part 1: General rules
IEC 62040-2:2005, Uninterruptible power systems (UPS) – Part 2: Electromagnetic
compatibility (EMC) requirements
IEC 62477-1:2012, Safety requirements for power electronic converter systems and
equipment – Part 1: General
3 Terms and definitions
Clause 3 of IEC 62477-1:2012 applies, except as follows:
Add the following new terms and definitions, and new notes:
___________
th th th
edition (2006). This 4 edition has been replaced in 2016 by a 5 edition IEC 60947-2:2016, Low-voltage
switchgear and controlgear – Part 2: Circuit-breakers.
nd nd rd
2 edition (2005). This 2 edition has been replaced in 2016 by a 3 edition IEC 62040-2:2016,
Uninterruptible power systems (UPS) – Part 2: Electromagnetic compatibility (EMC) requirements.

IEC 62040-1:2017 © IEC 2017 – 9 –
Table 1 – Alphabetical list of terms
Terms Term number Terms Term number
62040-1 62477-1 62040-1 62477-1
adjacent circuit 3.1 power semiconductor device 3.34
active power 3.111 primary power 3.108
apparent power 3.112 prospective short-circuit 3.122
current
backfeed 3.127 protective equipotential 3.36
bonding
backfeed protection 3.128 protective class I 3.37
basic insulation 3.2 protective class II 3.38
basic protection 3.3 protective class III 3.39
bypass 3.110 protective earthing (PE) 3.40
commissioning test 3.4 PE conductor 3.41
cord 3.109 protective impedance 3.42
decisive voltage class 3.5 (electrically) protective 3.43
(DVC) screening
double insulation 3.6 protective separation 3.44
DVC As 3.7 PEC 3.45
DVC Ax 3.8 PECS 3.46
earth fault 3.131 rated conditional short-circuit 3.120
current
electrical breakdown 3.9 rated current 3.117
(electrical) insulation 3.10 rated load 3.115
(electronic) (power) 3.11 rated peak withstand current 3.118
conversion
enclosure 3.12 rated short-time withstand 3.119
current
enhanced protection 3.13 rating 3.113
expected lifetime 3.14 rated value 3.114
Extra Low Voltage (ELV) 3.15 rated voltage 3.116
fault protection 3.16 reference non-linear load 3.126
field wiring terminal 3.17 reference test load 3.125
fire enclosure 3.18 reinforced insulation 3.47
functional insulation 3.19 restricted access area 3.48
hazardous energy 3.107 routine test 3.49
hazardous live part 3.20 sample test 3.50
hazardous voltage 3.106 SELV (systems) 3.51
installation 3.21 short-circuit backup protection 3.52
instructed person 3.103 service acces area 3.105
linear load 3.123 short-circuit protective device 3.130
(SCPD)
live part 3.22 simple separation 3.53
low impedance path 3.121 single fault condition 3.54
low voltage 3.23 skilled person 3.102
mains supply 3.24 startle reaction 3.55
muscular reaction (inability 3.25 supplementary insulation 3.56
to let go)
– 10 – IEC 62040-1:2017 © IEC 2017
Terms Term number Terms Term number
62040-1 62477-1 62040-1 62477-1
non-linear load 3.124 surge protective device (SPD) 3.57
non-mains supply 3.26 system 3.58
open type 3.27 system voltage 3.59
ordinary person 3.104 stored energy mode 3.129
output short-circuit current 3.28 temporary overvoltage 3.60
PELV (systems) 3.29 touch current 3.61
Permanently connected 3.30 type test 3.62
pluggable equipment 3.31 ventricular fibrillation 3.63
type A
pluggable equipment 3.32 working voltage 3.64
type B
port 3.33 uninterruptible power system 3.101
(UPS)
zone of equipotential bonding 3.65

Note 1 to entry: Where the terms "voltage" and "current" are used, RMS values are implied unless otherwise
specified.
Note 2 to entry: Non-sinusoidal signals are measured with appropriate true RMS measuring instruments.
3.101
uninterruptible power system
UPS
combination of convertors, switches and energy storage devices (such as batteries),
constituting a power system for maintaining continuity of load power in case of input power
failure
Note 1 to entry: Continuity of load power occurs when voltage and frequency are within rated steady-state and
transient tolerance bands, and with distortion and interruptions within the limits specified for the output port. Input
power failure occurs when voltage and frequency are outside rated steady-state and transient tolerance bands, or
with distortion or interruptions outside the limits specified for the UPS.
3.102
skilled person
person with relevant education and experience to enable him or her to perceive risks and to
avoid hazards which the equipment can create
Note 1 to entry: Such person has access to restricted access areas.
[SOURCE: IEC 60050-195:1998, 195-04-01, modified – The word "(electrically)" has been
deleted from the term, and "electricity" has been replaced by "the equipment" in the definition.
The note has been added.]
3.103
instructed person
person adequately advised or supervised by skilled persons to enable him or her to perceive
risks and to avoid hazards which the equipment can create
Note 1 to entry: Such person has access to restricted access areas.
Note 2 to entry: Examples of activities performed by an instructed person can be found in IEC 61140:2001,
Clause 8.
[SOURCE: IEC 60050-195:1998, 195-04-02, modified – The word "(electrically)" has been
deleted from the term, and the notes have been added.]

IEC 62040-1:2017 © IEC 2017 – 11 –
3.104
ordinary person
person who is neither a skilled person nor an instructed person
Note 1 to entry: Such person does not have access to a restricted access area and is not trained to identify
hazards. Such person may otherwise have access to the equipment or may be in the vicinity of the equipment. An
ordinary person will not intentionally create hazards nor have access to hazardous parts under normal and single
fault conditions.
[SOURCE: IEC 60050-195:1998, 195-04-03, modified – The note has been added.]
3.105
service access area
area accessible by skilled persons by the use of a tool, where it is necessary for skilled
person to have access regardless of the equipment being energized
3.106
hazardous voltage
voltage exceeding 42,4 V peak, or 60 V DC, existing in a circuit that does not meet the
requirements for either a limited current circuit or a TNV-1 circuit
Note 1 to entry: A limited current circuit is understood in the context of "protection by means of protective
impedance" as described in IEC 62477-1:2012, 4.4.5.4.
[SOURCE: IEC 60950-1:2005, 1.2.8.6 modified – TNV has been replaced by TNV-1.]
3.107
hazardous energy
available power level of 240 VA or more, having a duration of 60 s or more, or a stored energy
level of 20 J or more (for example, from one or more capacitors), at a potential of 2 V or more
Note 1 to entry: See IEC 62477-1:2012, 4.5.1.2.
3.108
primary power
power supplied by an electrical utility company or by a local generator
3.109
cord
flexible cable with a limited number of conductors of small cross-sectional area
[SOURCE: IEC 60050-461:2008, 461-06-15.]
3.110
bypass
alternative power path, either internal or external to the UPS
3.111
active power
under periodic conditions, mean value, taken over one period T, of the instantaneous power p
T
P = pdt
∫
T
Note 1 to entry: Under sinusoidal conditions, the active power is the real part of the complex power S, thus
P = Re S
Note 2 to entry: The coherent SI unit for active power is watt, W.

– 12 – IEC 62040-1:2017 © IEC 2017
Note 3 to entry: DC, fundamental and harmonic voltages and currents contribute to the magnitude of the active
power. Where applicable, instruments used to measure active power should therefore present sufficient
bandwidth and be capable of measuring any significant non-symmetrical and harmonic power components.
[SOURCE: IEC 60050-131: 2013, 131-11-42, modified – A third note to entry has been
added.]
3.112
apparent power
product of the RMS voltage and RMS current
3.113
rating
set of rated values and operating conditions of a machine, a device or equipment
[SOURCE: IEC 60050-151:2001, 151-16-11, modified – The words "of a machine, a device or
equipment" have been added.]
3.114
rated value
value of a quantity used for specification purposes, generally established by a manufacturer
for a specified set of operating conditions of a component, device, equipment, or system
[SOURCE: IEC 60050-151:2001, 151-16-08, modified – The word "established" has been
expanded to read "generally established by a manufacturer".]
3.115
rated load
load or condition in which the output of the UPS delivers the power for which the UPS is rated
Note 1 to entry: The rated load is expressed in apparent power (VA) and active power (W) resulting in a (rated)
power factor that includes the effect of any applicable combination of linear and of non-linear load as prescribed
in Annex BB.
Note 2 to entry: Rated load is a value of load used for specification purposes, generally established by a
manufacturer for a specified set of operating conditions of a component, device, equipment, or system
3.116
rated voltage
input or output voltage as declared by the manufacturer
Note 1 to entry: For a three-phase supply, the rated voltage corresponds to the phase-to-phase voltage.
3.117
rated current
input or output current of the UPS as declared by the manufacturer
3.118
rated peak withstand current
I
pk
value of peak short-circuit current, declared by the UPS manufacturer, that can be withstood
under specified conditions
Note 1 to entry: For the purpose of this document, I refers to the initial asymmetric peak value of the

pk
prospective test current listed in Table 104.
3.119
rated short-time withstand current
I
cw
RMS value of short-time current, declared by the UPS manufacturer, that can be carried under
specified conditions, defined in terms of current and time

IEC 62040-1:2017 © IEC 2017 – 13 –
[SOURCE: IEC 61439-1:2011, 3.8.10.3, modified – The definition has been rephrased and
the word "assembly" has been replaced by "UPS".]
3.120
rated conditional short-circuit current

I
cc
RMS value of prospective short-circuit current, declared by the UPS manufacturer, that can
be withstood for the total operating time (clearing time) of the short-circuit protective device
(SCPD) under specified conditions
Note 1 to entry: The short-circuit protective device does not necessarily form an integral part of the UPS.
[SOURCE: IEC 61439-1:2011, 3.8.10.4, modified – The word "RMS" has been added to
"value", the word "assembly" has been replaced by "UPS", and the note has been rephrased.]
3.121
low impedance path
path containing devices that for UPS load purposes present negligible impedance, such as
cabling, switching devices, protecting devices and filtering devices
Note 1 to entry: The devices in a low impedance path generally present current limiting characteristics under
short-circuit conditions.
Note 2 to entry: Examples include current limiting fuses, current limiting circuit-breakers, transformers and
inductors.
3.122
prospective short-circuit current
I
cp
RMS value of the current which would flow if the supply conductors to the circuit are short-
circuited by a conductor of negligible impedance located as near as practicable to the supply
terminals of the UPS
[SOURCE: IEC 61439-1:2011, 3.8.7, modified – The word "assembly" has been replaced by
"UPS".]
3.123
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 constant load impedance
Note 1 to entry: Application of a linear load to a sinusoidal voltage results in a sinusoidal current.
[SOURCE: IEC 62040-3:2011, 3.2.4]
3.124
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
[SOURCE: IEC 62040-3:2011, 3.2.5]

– 14 – IEC 62040-1:2017 © IEC 2017
3.125
reference test load
load or condition in which the output of the UPS delivers the active power (W) for which the
UPS is rated
Note 1 to entry: This definition permits, when in test mode and subject to local regulations, the UPS output to be
injected into the input AC supply.
[SOURCE: IEC 62040-3:2011, 3.3.5]
3.126
reference non-linear load
non-linear load that when connected to a UPS, consumes the apparent power at which the
UPS shall be tested
Note 1 to entry: Refer to Clause BB.5 for test details.
[SOURCE: IEC 62040-3:2011, 3.3.6, modified – The expression "the apparent and active
power for which the UPS is rated in accordance with Annex E" has been replaced by "the
apparent power at which the UPS shall be tested", and the note has been added.]
3.127
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
[SOURCE: IEC 62040-3:2011, 3.2.3, modified – The words "while AC input power is" have
been replaced by "with primary power".]
3.128
backfeed protection
control scheme that reduces the risk of electric shock due to backfeed
3.129
stored energy mode
stable mode of operation that the UPS attains under the following conditions:
a) AC input power is disconnected or is out of required tolerance;
b) all power is derived from the energy storage device;
c) the load is within the specified rating of the UPS
[SOURCE: IEC 62040-3:2011, 3.2.10, modified – The words "of UPS operation" have been
deleted in the term, and the word "system" has been replaced by "device" in b).]
3.130
short-circuit protective device
SCPD
device intended to protect a circuit or parts of a circuit against short-circuit currents by
interrupting them
[SOURCE: IEC 60947-1:2007, 2.2.21]
3.131
earth fault
occurrence of an accidental conductive path between a live conductor and the earth
[SOURCE: IEC 60050-826:2004, 826-04-14, modified – The second preferred term "ground
fault" has been deleted, as well as the notes.]

IEC 62040-1:2017 © IEC 2017 – 15 –
4 Protection against hazards
Clause 4 of IEC 62477-1:2012 applies, except as follows:
4.2 Fault and abnormal conditions
Subclause 4.2 in IEC 62477-1:2012 applies, except as follows:
Replace the fourth paragraph of IEC 62477-1:2012, 4.2 by the following:
Compliance is checked by analysis or by test according to 5.2.4.6 of IEC 62477-1:2012.
Compliance through analysis only is permitted when such analysis conclusively shows that no
hazard will result from failure of the component.
4.3 Short-circuit and overload protection
Subclause 4.3 in IEC 62477-1:2012 applies except as follows:
Add the following:
4.3.101 AC input current
The input current to the UPS shall not exceed that declared by the UPS manufacturer –
see 6.2 a).
In determining the steady state input current, the consumption due to optional features offered
or provided by the manufacturer for inclusion in or with the UPS shall be considered and
adjusted to give the most unfavourable result.
NOTE Transient input current arising from dynamic occurences, for example inrush or overload current, is not
considered.
Compliance is checked when highest current measured or calculated (as applicable) when
performing the test described in 5.2.3.102 does not exceed the input current declared by the
manufacturer (see 6.2).
4.3.102 Transformer protection
Transformers shall be protected against overtemperature.
NOTE Means of protection include:
• overcurrent protection,
• internal thermal cut-outs,
• use of current limiting devices.
Compliance is checked by the applicable tests of 5.2.3.104.
4.3.103 AC input short-circuit current
The UPS manufacturer shall specify the rated conditional short-circuit current (I ) or the
cc
rated short-time withstand current (I ) at each AC input port of the UPS. The UPS
cw
manufacturer may specify both. Individual AC input ports of a UPS may have individual
ratings.
A UPS with AC input ports that may be configured with jumpers or busbars to present a single
AC input port o
...