IEC 62040-1:2008/AMD1:2013

Amendment 1 - Uninterruptible power systems (UPS) - Part 1: General and safety requirements for UPS

Amendement 1 - Alimentations sans interruption (ASI) - Partie 1: Exigences générales et règles de sécurité pour les ASI

General Information

• Status: Published
• Publication Date: 09-Jan-2013
• ICS: 29.200 - Rectifiers. Convertors. Stabilized power supply
• Technical Committee: SC 22H - Uninterruptible power systems (UPS)
• Drafting Committee: MT 62040-1 - TC 22/SC 22H/MT 62040-1
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 12-Jul-2017

Relations

• Revised: IEC 62040-1:2017 - Uninterruptible power systems (UPS) - Part 1: Safety requirements
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 62040-1


®


Edition 1.0 2013-01



INTERNATIONAL



STANDARD



NORME
INTERNATIONALE
AMENDMENT 1
AMENDEMENT 1

Uninterruptible power systems (UPS) –
Part 1: General and safety requirements for UPS

Alimentations sans interruption (ASI) –
Partie 1: Exigences générales et règles de sécurité pour les ASI


IEC 62040-1:2008/A1:2013

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IEC 62040-1



®



Edition 1.0 2013-01







INTERNATIONAL





STANDARD







NORME



INTERNATIONALE




AMENDMENT 1

AMENDEMENT 1





Uninterruptible power systems (UPS) –

Part 1: General and safety requirements for UPS




Alimentations sans interruption (ASI) –

Partie 1: Exigences générales et règles de sécurité pour les ASI

















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE

PRICE CODE
INTERNATIONALE

CODE PRIX J


ICS 29.200 ISBN 978-2-83220-559-4



Warning! Make sure that you obtained this publication from an authorized distributor.

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® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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– 2 – 62040-1 Amend.1 © IEC:2013



FOREWORD


This amendment has been prepared by subcommittee 22H: Uninterruptible power systems

(UPS), of IEC technical committee 22: Power electronic systems and equipment.


The text of this amendment is based on the following documents:


FDIS Report on voting


22H/151/FDIS 22H/155/RVD


Full information on the voting for the approval of this amendment can be found in the report
on voting indicated in the above table.
The committee has decided that the contents of this amendment and the base publication will
remain unchanged until the stability date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

_____________
INTRODUCTION TO THE AMENDMENT
This amendment determines the short-time withstand current test requirements for the
purpose of verifying the safety of the UPS when a short circuit is applied across the output
terminals under prescribed modes of operation wherein the output power is delivered by the
a.c. input through a low impedance path.
FOREWORD
Add, at the end of the list beginning " – update of normative references" the following new
item:

– Amendment 1 introduces short-time withstand current requirements when a short-circuit is
applied at the output of the UPS (5.5.4).

2 Normative references
Add the following new reference:
IEC 61439-1:2011, Low-voltage switchgear and controlgear assemblies – Part 1: General
rules

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62040-1 Amend.1 © IEC:2013 – 3 –


3.2 UPS electrical ratings


Add the following new terms and definitions:


3.2.4

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 For the purpose of this standard, I refers to the initial asymmetric peak value of the prospective test

pk
current listed in Table 3

3.2.5
rated short-time withstand current
I
cw
r.m.s. value of short-time current, declared by the UPS manufacturer, that can be carried
without damage under specified conditions, defined in terms of current and time
3.2.6
rated conditional short-circuit current
I
cc
r.m.s. 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 The short-circuit protective device may form an integral part of the UPS or may be a separate unit.
3.2.7
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 The devices in a low impedance path may under short-circuit conditions present current limiting
characteristics. Examples include current limiting fuses, current limiting circuit-breakers, transformers and
inductors.
3.2.8
prospective short-circuit current
I
cp
r.m.s. 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


4.7.2 Power rating
Add to the end of the list, the following new item:
– rated short-time withstand current (I ) or rated conditional short-circuit current (I )
cw cc
in accordance with 5.5.4.
Renumber the existing note as Note 1 and add the following new Note 2:
NOTE 2 Table 3 values may be exceeded and so marked.

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– 4 – 62040-1 Amend.1 © IEC:2013


4.7.12 Protection in building installation


Add the following paragraphs at the beginning of 4.7.12:


The UPS manufacturer shall state, as applicable, the rated short-time withstand current,

(I ) or rated conditional short circuit current (I ). This current shall be equal to or higher
cw cc

than the I value stated in 5.5.4.3.1 (column 2 of Table 3).
cp


If an I value higher than that specified in Table 3 is stated, the following applies.
cp

a) If higher I stated ≤ 10 kA:
cp

the values corresponding to the next higher applicable line of Table 3 apply.
b) If higher I stated > 10 kA:
cp
values 16 kA, 20 kA, 25 kA, 35 kA, 50 kA, 65 kA, 85 kA, 100 kA are preferred and the
values corresponding to line 500 < I of Table 3 apply.
NOTE 1 Examples of Table 3 line values to be used when a higher I or I is stated.
cw cc
a) If a 50 A UPS is declared to sustain I = 8 kA (instead of 6 kA), use the values of line 75 < I < 400 in Table 3.
cw
b) If a 1 000 A UPS is declared to sustain I = 85 kA (instead of 20 × 1 000 = 20 kA), use the values of line
cw
500 < I in Table 3.
The installer can then verify that the prospective short-circuit current resulting at the a.c.
input terminals of the unit is equal to or less than the value declared by the UPS
manufacturer. Otherwise, subject to an agreement between the manufacturer and the user, a
solution shall be procured. Such a solution may consist in employing external current-limiting
overcurrent protectors or customizing the UPS accordingly.
Irrespective of the UPS being a single unit or a unit in a paralleled system, the prospective
short-circuit current of the a.c. input to be verified is that available at the relevant
connection point of each unit.
Renumber the existing note as Note 2.

5.5 Overcurrent and earth fault protection
Add the following subclause:
5.5.4 Short-time withstand current

5.5.4.1 General
The short-time withstand current test shall be performed as a type test to verify the safety
of the UPS when a short circuit is applied across the output terminals under prescribed modes
of operation, except where exempted. Refer to Annex P, Figure P.1 for a typical circuit for
implementation of the test and to 5.5.4.3.2 for exemptions.
NOTE Internal faults are not considered in this section. The effect of faults originated within the UPS are
addressed in 8.3.
5.5.4.2 Modes of operation
Testing is performed only in modes of operation wherein the output power is delivered by the
a.c. input through a low impedance path.
NOTE 1 Examples of such modes of operation include:
– input voltage and frequency dependent (VFD) UPS operating in normal and/or bypass modes;

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62040-1 Amend.1 © IEC:2013 – 5 –


– input voltage independent (VI) UPS operating in normal and/or bypass modes;

– input voltage and frequency independent (VFI) UPS when operating in bypass mode;

– any UPS with built-in maintenance bypass switch when operating in maintenance bypass mode.


NOTE 2 UPS performance classifications VFD, VI and VFI are detailed in IEC 62040-3.

5.5.4.3 Test procedure


5.5.4.3.1 General application


The UPS a.c. input shall be connected to a supply capable of delivering the prospective test

current in accordance with Table 3. The UPS shall be in the appropriate mode of operation

(see 5.5.4.2) and otherwise operating without load and at rated input voltage and frequency. A
short-circuit shall then be applied across the output terminals of the UPS. A UPS rated for
multiple input and output voltages may be tested at any of its rated input voltages provided
that applicable interrupting components have been certified or tested to interrupt the
prospective test current at the highest rated input voltage.
NOTE 1 The manufacturer can opt to perform additional tests at other rated voltages and currents.
NOTE 2 For consideration in a future edition of this standard, the making capability of the short-circuit current into
the low impedance path can be verified for safety purposes. Such verification could involve tests or analysis of
component documentation. Examples include a UPS that in normal mode of operation, does not supply the output
terminals through a low impedance path, but that upon application of a short-circuit across the output terminals,
automatically transfers into a low impedance path.
NOTE 3 For consideration in a future edition of this standard it will be evaluated whether tests would be permitted
at voltages lower than rated and, subject to the phase current being observed not interrupted throughout the
minimum duration listed in Table 3, whether the manufacturer could then declare the I to be the phase current
cw
recorded during the test.
The test shall be repeated by placing a short circuit across the phase closest to the neutral
terminal when the latter is provided. However, the phase-to-neutral test is not required when
the neutral construction is at least as robust as that of the phase conductors in terms of cross-
sectional area, mechanical support and clearance.
If the manufacturer declares a short-time withstand current higher than shown in Table 3, the
declared value applies for test purposes.
The test is considered complete when the prospective test current has been made available
for the minimum duration listed in Table 3.

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– 6 – 62040-1 Amend.1 © IEC:2013


Table 3 – Short time withstand current

a
Rated UPS Prospective test current Initial asymmetric Minimum

e
output current I peak current ratio duration of

(r.m.s.) Typical
(r.m.s.) (I / I ) prospective test
pk cw
b e
f
A power factor
A current
(cycles 50/60 Hz)

c d
1 000 0,95

I ≤ 16 1,42 1,5

3 000 0,9

16 < I ≤ 75 6 000 0,7 1,53 1,5

10 000 0,5 1,70 1,5
75 < I ≤ 400

400 < I ≤ 500 10 000 0,5 1,70 3,0
20 x I or 50 kA 0,5 – 0,3 × (I - 500) / 2 000 (0,5 I + 3 150) / 2 000
500 < I whichever is or 0,2 whichever is the or 2,2 3,0
the lower whichever is the lower
higher
NOTE 1 Depending on the characteristics of the UPS the actual values observed during the test may be
different from those listed in Table 3.
NOTE 2 Refer to 4.7.12 for conditions applying if the I value declared is higher than that specified in
cp
Table 3.
NOTE 3 Minimum duration of prospective test current can be increased when required by national deviation.
a
Prospective test current, in the context of this standard, shall be understood as prospective short-circuit
current (I ) – refer to 3.2.8.
cp
b
Values compatible with Table 4 of IEC 60947-6-1:2005.
c
Pluggable UPS only.
d
The typical fault current of public supply networks rated 75 A and below and intended to supply equipment
with a rated current of 16 A or below can be calculated from the reference impedances in IEC/TR 60725:
2005: phase conductor 0,24 + j0,15 Ω and neutral conductor 0,16 + j0,10 Ω. For 230 V/400 V supplies this
results in typical fault currents of 0,5 kA (230 V) and 0,7 kA (400 V).
e
From Table 16 of IEC 60947-1:2007.
f
From 5.3.6.1 of IEC 60947-6-1:2005.

Compliance is verified when, at the conclusion of the test, the following criteria are satisfied.
a) The UPS shall not have emitted flames, molten metal or burning particles, other than, for
example, metal particles normally emitted from a circuit breaker when it clears a fault.
NOTE 4 Refer to 7.5 for further guidance as required.
b) There shall have been no arcing from live parts to the UPS chassis or enclosure.

NOTE 5 An intact enclosure test fuse as described in Annex P indicates compliance. The use of an enclosure
test fuse is not applicable for UPS with non conductive chassis or enclosure (e.g. plastic case)
c) Components, e.g. busbar supports, used for the mounting of live parts shall not break
away from their initial position.
d) Any enclosure door shall not open rapidly (so as to cause injury) when protected only by
its normal latch.
e) No conductor shall get pulled out of its terminal connector and there shall be no damage
to the conductor or conductor insulation.
f) The UPS shall successfully pass the electric strength tests as specified in 8.2.
5.5.4.3.2 Exemption from testing
Exemption from short-time withstand current testing applies to:
a) UPS with declared I or I not exceeding 10 kA;
cw cc

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62040-1 Amend.1 © IEC:2013 – 7 –


b) UPS protected by current-limiting devices having a cut-off current not exceeding 17 kA

with the maximum allowable prospective short-circuit current at the terminals of the

incoming circuit of the UPS;

c) UPS intended to be supplied from transformers whose rated power does not exceed

10 kVA per phase for a rated secondary voltage of not less than 110 V, or 1,6 kVA per

phase for a rated secondary voltage less than 110 V, and whose short-circuit impedance

is not less than 4 %;

d) UPS variants of a more onerous UPS tested compliant with the test requirements

prescribed in 5.5.4.3.1;


For guidance on how to determine when a UPS is a variant of a more onerous UPS, refer to

10.11.3 and Table 13 (check list) or 10.11.4 (calculation) of IEC 61439-1:2011.
NOTE The exemption conditions above align Amendment 1 of this standard with 10.11.2 of IEC 61439-1:2011 that
should be considered.
Compliance is verified by satisfying at least one of the exemption conditions.
Add, after existing Annex O, the following new Annex P:

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– 8 – 62040-1 Amend.1 © IEC:2013


Annex P

(informative)



Short-time withstand current test procedure –

Guidance and typical values


P.1 General


This annex presents circuits and methods that are typical for the implementation of the short-

time withstand current test prescribed in 5.5.4. The test circuit in Figure P.1 can be used to

carry out the test.
NOTE Further guidance can be found in 10.11.5.2 of IEC 61439-1:2011.

AC source
Key
AC source   rated voltage, 3-phase as applicable
F1    conditional withstand protection device
           e.g. fuses or circuit breaker if specified
           by the manufacturer
F1
R       adjustable resistor
X    source reactance implemented with linear
           reactors that may be adjustable and of air-core
           technology
EUT       equipment under test
R
F       enclosure fuse (for positive verification of arcing
           to chassis, as applicable)
SW       closing switch – may be located as shown or ahead
           of limiting impedance
X

AC input terminals
EUT
F
Load terminals

SW
IEC  2378/12


NOTE Since the transient recovery voltage characteristics of test circuits, including large air-core reactors, are
not representative of usual service conditions, any air-core reactor in each phase should be shunted by a resistor
(not shown in the diagram) taking approximately 0,6 % of the current through the reactor.
Figure P.1 – Test circuit for UPS short-time withstand current

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62040-1 Amend.1 © IEC:2013 – 9 –


P.2 Test set up


The UPS output should be set up as prescribed in 5.5.4.3.



P.3 Calibration of the test circuit


The resistance and reactance of the test circuit, if applied to the rated a.c. input source,

should provide the current listed in Table 3 and satisfy the test conditions specified in Table 3.

The source reactance is represented by X that should be implemented with linear reactors

that may be adjustable and of air-core technology. They should be connected in series with

the resistors R. The parallel connecting of reactors is acceptable when these reactors have
practically the same time constant. The leads to the unit under test should be includ
...