EN 60831-1:2014

SLOVENSKI STANDARD
01-junij-2015
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SIST EN 60831-1:1999
SIST EN 60831-1:1999/A1:2003
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Shunt power capacitors of the self-healing type for a.c. systems having a rated voltage
up to and including 1000 V - Part 1: General - Performance, testing and rating - Safety
requirements - Guide for installation and operation
/
Condensateurs shunt de puissance autorégénérateurs pour réseaux à courant alternatif
de tension assignée inférieure ou égale à 1000 V - Partie 1: Généralités -
Caractéristiques fonctionnelles, essais et valeurs assignées - Exigences de sécurité -
Guide d'installation et d'exploitation
Ta slovenski standard je istoveten z: EN 60831-1:2014
ICS:
31.060.70 0RþQRVWQLNRQGHQ]DWRUML Power capacitors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 60831-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2014
ICS 29.120.99; 31.060.70 Supersedes EN 60831-1:1996
English Version
Shunt power capacitors of the self-healing type for a.c. systems
having a rated voltage up to and including 1 000 V - Part 1:
General - Performance, testing and rating - Safety requirements
- Guide for installation and operation
(IEC 60831-1:2014)
Condensateurs shunt de puissance autoregénérateurs pour Selbstheilende Leistungs-Parallelkondensatoren für
réseaux à courant alternatif de tension assignée inférieure Wechselstromanlagen mit einer Bemessungsspannung bis
ou égale à 1 000 V - Partie 1: Généralités - Caractéristiques 1 000 V - Teil 1: Allgemeines - Leistungsanforderungen,
fonctionnelles, essais et valeurs assignées - Règles de Prüfung und Bemessung - Sicherheitsanforderungen -
sécurité - Guide d'installation et d'exploitation Anleitung für Errichtung und Betrieb
(CEI 60831-1:2014) (IEC 60831-1:2014)
This European Standard was approved by CENELEC on 2014-03-18. 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, 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: Avenue Marnix 17, B-1000 Brussels
© 2014 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 60831-1:2014 E
Foreword
The text of document 33/543/FDIS, future edition 3 of IEC 60831-1, prepared by IEC/TC 33, "Power
capacitors and their applications" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN 60831-1:2014.
The following dates are fixed:
(dop) 2014-12-18
• latest date by which the document has
to be implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2017-03-18

standards conflicting with the
document have to be withdrawn
This document supersedes EN 60831-1:1996 + A1:2003.
1:1996 + A1:2003:
a) Updating of the normative references;
b) Test conditions have been clarified;
c) Thermal stability test has been clarified;
d) Maximum permissible voltage and current have been clarified;
e) The protection of the environment has been amended with safety concerns and plastic quality
requirements.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
This standard covers the Principle Elements of the Safety Objectives for Electrical Equipment
Designed for Use within Certain Voltage Limits (LVD - 2006/95/EC).
Endorsement notice
The text of the International Standard IEC 60831-1:2014 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 60060-2:2010 NOTE Harmonised as EN 60060-2:2011 (not modified).
IEC 60110-1:1998 NOTE Harmonised as EN 60110-1:1998 (not modified).
IEC 60143-1 NOTE Harmonised as EN 60143-1 (not modified).
IEC 60143-2 NOTE Harmonised as EN 60143-2 (not modified).
IEC 60143-3 NOTE Harmonised as EN 60143-3 (not modified).
IEC 60143-4 NOTE Harmonised as EN 60143-4 (not modified).
IEC 60252-1:2010 NOTE Harmonised as EN 60252-1:2011 (not modified).

- 3 - EN 60831-1:2014
IEC 60358-1 NOTE Harmonised as EN 60358-1 (not modified).
IEC 61048:2006 NOTE Harmonised as EN 61048:2006 (not modified).
IEC 61049:1991 NOTE Harmonised as EN 61049:1993 (modified).
IEC 61071 (series) NOTE Harmonised as EN 61071 (series) (not modified).

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.

NOTE 1 When 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 60060-1 2010 High-voltage test techniques - Part 1: General EN 60060-1 2010
definitions and test requirements

IEC 60269-1 2006 Low-voltage fuses - Part 1: General EN 60269-1 2007
requirements
IEC 60695-2-12 2010 Fire hazard testing - Part 2-12: Glowing/hot- EN 60695-2-12 2010
wire based test methods - Glow-wire
flammability index (GWFI) test method for
materials
IEC 60831-2 2014 Shunt power capacitors of the self-healing EN 60831-2 2014
type for a.c. systems having a rated voltage
up to and including 1000 V - Part 2: Ageing
test, self-healing test and destruction test

IEC 61000-2-2 2002 Electromagnetic compatibility (EMC) - Part 2- EN 61000-2-2 2002
2: Environment - Compatibility levels for low-
frequency conducted disturbances and
signalling in public low-voltage power supply
systems
IEC 61000-4-1 2006 Electromagnetic compatibility (EMC) - Part 4- EN 61000-4-1 2007
1: Testing and measurement techniques -
Overview of IEC 61000-4 series

IEC 60831-1 ®
Edition 3.0 2014-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Shunt power capacitors of the self-healing type for a.c. systems having a rated

voltage up to and including 1 000 V –

Part 1: General – Performance, testing and rating – Safety requirements – Guide

for installation and operation

Condensateurs shunt de puissance autoregénérateurs pour réseaux à courant

alternatif de tension assignée inférieure ou égale à 1 000 V –

Partie 1: Généralités – Caractéristiques fonctionnelles, essais et valeurs

assignées – Règles de sécurité – Guide d'installation et d'exploitation

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
W
CODE PRIX
ICS 29.120.99; 31.060.70 ISBN 978-2-8322-1391-9

– 2 – 60831-1 © IEC:2014
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 8
3 Terms and definitions . 8
4 Service conditions . 11
4.1 Normal service conditions . 11
4.2 Unusual service conditions . 12
5 Test requirements. 12
5.1 General . 12
5.2 Test conditions . 13
6 Classification of tests . 13
6.1 Routine tests. 13
6.2 Type tests . 13
6.3 Acceptance tests . 14
7 Capacitance measurement and output calculation . 14
7.1 Measuring procedure . 14
7.2 Capacitance tolerances . 14
8 Measurement of the tangent of the loss angle (tan δ) of the capacitor . 15
8.1 Measuring procedure . 15
8.2 Loss requirements . 15
9 Voltage tests between terminals . 15
9.1 Routine test . 15
9.2 Type test . 15
10 Voltage tests between terminals and container . 16
10.1 Routine test . 16
10.2 Type test . 16
11 Test of internal discharge device . 17
12 Sealing test . 17
13 Thermal stability test . 17
14 Measurement of the tangent of the loss angle (tan δ) of the capacitor at elevated
temperature . 19
14.1 Measuring procedure . 19
14.2 Requirements . 19
15 Lightning impulse voltage test between terminals and container . 19
16 Discharge test . 19
17 Ageing test . 20
18 Self-healing test . 20
19 Destruction test . 20
20 Maximum permissible voltage . 20
20.1 Long-duration voltages . 20
20.2 Switching voltages . 21
21 Maximum permissible current . 21
22 Discharge device . 21
23 Container connections . 22

60831-1 © IEC:2014 – 3 –
24 Protection of the environment . 22
25 Other safety requirements . 22
26 Marking of the unit . 22
26.1 Rating plate . 22
26.2 Standardized connection symbols . 23
26.3 Warning plate . 23
27 Marking of the bank . 23
27.1 Instruction sheet or rating plate . 23
27.2 Warning plate . 23
28 General . 24
29 Choice of the rated voltage . 24
30 Operating temperature . 25
30.1 General . 25
30.2 Installation . 25
30.3 High ambient air temperature . 25
30.4 Evaluation of losses . 25
31 Special service conditions . 26
32 Overvoltages . 26
33 Overload currents . 27
34 Switching and protective devices and connections . 27
35 Choice of creepage distance . 28
36 Capacitors connected to systems with audio-frequency remote control . 29
37 Electromagnetic compatibility (EMC) . 29
37.1 Emission . 29
37.2 Immunity . 29
37.2.1 General . 29
37.2.2 Low-frequency disturbances . 29
37.2.3 Conducted transients and high-frequency disturbances . 29
37.2.4 Electrostatic discharges . 29
37.2.5 Magnetic disturbances . 30
37.2.6 Electromagnetic disturbances . 30
Annex A (normative) Additional definitions, requirements and tests for power filter
capacitors . 31
A.1 Terms and definitions . 31
A.2 Quality requirements and tests . 31
A.2.1 Capacitance tolerance . 31
A.2.2 Voltage test between terminals (see Clause 9) . 32
A.2.3 Thermal stability test (see Clause 13) . 32
A.3 Overloads – Maximum permissible current (see Clause 21) . 32
A.4 Markings – Instruction sheet or rating plate (see 27.1) . 32
A.5 Guide for installation and operation – Choice of the rated voltage (see
Clause 29) . 32
Annex B (informative) Formulae for capacitors and installations . 33
B.1 Computation of the output of three-phase capacitors from three single-
phase capacitance measurements . 33
B.2 Resonance frequency . 33
B.3 Voltage rise . 33

– 4 – 60831-1 © IEC:2014
B.4 Inrush transient current . 34
B.4.1 Switching in of single capacitor . 34
B.4.2 Switching of capacitors in parallel with energized capacitor(s) . 34
B.4.3 Discharge resistance in single-phase units or in one-phase or
polyphase units . 34
Bibliography . 36

Figure B.1 – k values depending on the method of connection of the resistors with the
capacitor units . 35

Table 1 – Letter symbols for upper limit of temperature range . 12
Table 2 – Ambient air temperature for the thermal stability test . 18
Table 3 – Admissible voltage levels in service . 20

60831-1 © IEC:2014 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SHUNT POWER CAPACITORS OF THE SELF-HEALING TYPE FOR A.C.
SYSTEMS HAVING A RATED VOLTAGE UP TO AND INCLUDING 1 000 V –

Part 1: General – Performance, testing and rating –
Safety requirements – Guide for installation and operation

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 60831-1 has been prepared by IEC technical committee 33: Power
capacitors and their applications.
This third edition cancels and replaces the second edition published in 1996 and Amendment
1:2002. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Updating of the normative references;
b) Test conditions have been clarified;
c) Thermal stability test has been clarified;
d) Maximum permissible voltage and current have been clarified;

– 6 – 60831-1 © IEC:2014
e) The protection of the environment has been amended with safety concerns and plastic
quality requirements.
The text of this standard is based on the following documents:
FDIS Report on voting
33/543/FDIS 33/550/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 2.
A list of all parts in the IEC 60831 series, published under the general title Shunt power
capacitors of the self-healing type for a.c. systems having a rated voltage up to and including,
1 000 V can be found on the IEC website.
The committee has decided that the contents of this 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.
The contents of the corrigendum of May 2014 have been included in this copy.

60831-1 © IEC:2014 – 7 –
SHUNT POWER CAPACITORS OF THE SELF-HEALING TYPE FOR A.C.
SYSTEMS HAVING A RATED VOLTAGE UP TO AND INCLUDING 1 000 V –

Part 1: General – Performance, testing and rating –
Safety requirements – Guide for installation and operation

1 Scope
This part of the IEC 60831 series is applicable to both capacitor units and capacitor banks
intended to be used, particularly, for power-factor correction of a.c. power systems having a
rated voltage up to and including 1 000 V and frequencies of 15 Hz to 60 Hz.
This part of IEC 60831 also applies to capacitors intended for use in power filter circuits.
Additional definitions, requirements, and tests for power filter capacitors are given in Annex A.
The following capacitors are excluded from this part of IEC 60831:
– Shunt power capacitors of the non-self-healing type for a.c. systems having a rated
voltage up to and including 1 000 V (IEC 60931-, -2 and -3).
– Shunt capacitors for a.c. power systems having a rated voltage above 1 000 V
(IEC 60871-1, -2, -3 and -4).
– Capacitors for inductive heat-generating plants operating at frequencies between 40 Hz
and 24 000 Hz (IEC 60110-1 and -2)
– Series capacitors (IEC60143-1, -2, -3 and -4)
– AC motor capacitors (IEC 60252-1 and -2)
– Coupling capacitors and capacitor dividers (IEC 60358-1)
– Capacitors for power electronic circuits (IEC 61071).
– Small a.c. capacitors to be used for fluorescent and discharge lamps (IEC 61048 and
IEC 61049).
– Capacitors for suppression of radio interference (under consideration).
– Capacitors intended to be used in various types of electrical equipment, and thus
considered as components.
– Capacitors intended for use with d.c. voltage superimposed on the a.c. voltage.
Accessories such as insulators, switches, instrument transformers, fuses, etc., should be in
accordance with the relevant IEC standards and are not covered by the scope of this part of
IEC 60831.
The object of this part of IEC 60831 is to:
a) formulate uniform rules regarding performances, testing and rating;
b) formulate specific safety rules;
c) provide a guide for installation and operation.

– 8 – 60831-1 © IEC:2014
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60060-1:2010, High-voltage test techniques – Part 1: General definitions and test
requirements
IEC 60269-1:2006, Low-voltage fuses – Part 1: General requirements
IEC 60831-2:2013, Shunt power capacitors of the self-healing type for a.c. systems having a
rated voltage up to and including 1 000 V – Part 2: Ageing test, self-healing test and
destruction test
IEC 60695-2-12:2010, Fire hazard testing – Part 2-12: Glowing/hot-wire based test methods –
Glow-wire flammability index (GWFI) test method for materials
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 61000-4-1:2006, Electromagnetic compatibility (EMC) – Part 4-1: Testing and
measurement techniques – Overview of IEC 61000-4 series
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
capacitor element
element
device consisting essentially of two electrodes separated by a dielectric
[SOURCE: IEC 60050-436:1990, 436-01-03]
3.2
capacitor unit
unit
assembly of one or more capacitor elements in the same container with terminals brought out
[SOURCE: IEC 60050-436:1990, 436-01-04]
3.3
self-healing capacitor
capacitor of which the electrical properties, after local breakdown of the dielectric, are rapidly
and essentially restored
[SOURCE: IEC 60050-436:1990, 436-03-12]
3.4
capacitor bank
bank
number of capacitor units connected so as to act together

60831-1 © IEC:2014 – 9 –
[SOURCE: IEC 60050-436:1990, 436-01-06]
3.5
capacitor
generic term, encompassing the notions of capacitor unit and capacitor bank
Note 1 to entry: In this part of IEC 60831, the word capacitor is used when it is not necessary to lay particular
stress upon the different meanings of the words capacitor unit or capacitor bank.
3.6
capacitor installation
one or more capacitor banks and their accessories
[SOURCE: IEC 60050-436:1990, 436-01-07]
3.7
discharge device of a capacitor
device which may be incorporated in a capacitor, capable of reducing the voltage between the
terminals practically to zero, within a given time, after the capacitor has been disconnected
from a network
[SOURCE: IEC 60050-436:1990, 436-03-15, modified ("intended to reduce … value" has been
replaced by "capable of reducing … zero")]
3.8
internal fuse of a capacitor
fuse connected inside a capacitor unit, in series with an element or a group of elements
[SOURCE: IEC 60050-436:1990, 436-03-16]
3.9
overpressure disconnector for a capacitor
disconnecting device designed to switch off the capacitor in the case of abnormal increase of
the internal pressure
[SOURCE: IEC 60050-436:1990, 436-03-17, modified ("to interrupt … in the event" has been
replaced by "to switch off … in the case")]
3.10
overtemperature disconnector for a capacitor
disconnecting device designed to switch off the capacitor in the case of abnormal increase of
the internal temperature
3.11
line terminal
terminal intended for connection to a line conductor of a network
Note 1 to entry: In polyphase capacitors, a terminal intended to be connected to the neutral conductor is not
considered to be a line terminal.
[SOURCE: IEC 60050-436:1990, 436-03-01]
3.12
rated capacitance of a capacitor
C
N
capacitance value for which the capacitor has been designed

– 10 – 60831-1 © IEC:2014
[SOURCE: IEC 60050-436:1990, 436-01-12, modified (symbol C added and "the r.m.s. value
N
of the alternating current" has been replaced by "capacitance value")]
3.13
rated output of a capacitor
Q
N
reactive power derived from the rated values of capacitance, frequency and voltage
[SOURCE: IEC 60050-436:1990, 436-01-16, modified (symbol Q added and "for which the
N
capacitor has been designed" has been replaced by "derived … voltage")]
3.14
rated voltage of a capacitor
U
N
r.m.s. value of the alternating voltage for which the capacitor has been designed
Note 1 to entry: In the case of capacitors consisting of one or more separate circuits (such as single-phase units
intended for use in polyphase connection, or polyphase units with separate circuits), U refers to the rated voltage
N
of each circuit.
For polyphase capacitors with internal electrical connections between the phases, and for polyphase capacitor
banks, U refers to the phase-to-phase voltage.
N
[SOURCE: IEC 60050-436:1990, 436-01-15]
3.15
rated frequency of a capacitor
f
N
frequency for which the capacitor has been designed
[SOURCE: IEC 60050-436:1990, 436-01-14]
3.16
rated current of a capacitor
I
N
r.m.s. value of the alternating current for which the capacitor has been designed
[SOURCE: IEC 60050-436:1990, 436-01-13]
3.17
capacitor losses
active power dissipated in the capacitor
Note 1 to entry: All loss-producing components should be included, for example:
– for a unit, losses from dielectric, internal fuses, internal discharge resistor, connections, etc.;
– for a bank, losses from units, external fuses, busbars, discharge and damping reactors, etc.
[SOURCE: IEC 60050-436:1990, 436-04-10]
3.18
tangent of the loss angle of a capacitor
tan δ
ratio between the equivalent series resistance and the capacitive reactance of the capacitor at
specified sinusoidal alternating voltage and frequency
[SOURCE: IEC 60050-436:1990, 436-04-11]

60831-1 © IEC:2014 – 11 –
3.19
maximum permissible a.c. voltage of a capacitor
maximum r.m.s. alternating voltage which the capacitor can sustain for a given time in
specified conditions
[SOURCE: IEC 60050-436:1990, 436-04-07]
3.20
maximum permissible a.c. current of a capacitor
maximum r.m.s. alternating current which the capacitor can sustain for a given time in
specified conditions
[SOURCE: IEC 60050-436:1990, 436-04-09]
3.21
ambient air temperature
temperature of the air at the proposed location of the capacitor
3.22
cooling air temperature
temperature of the cooling air measured at the hottest position in the bank, under steady-state
conditions, midway between two units
Note 1 to entry: If only one unit is involved, it is the temperature measured at a point approximately 0,1 m away
from the capacitor container and at two-thirds of the height from its base.
3.23
steady-state condition
thermal equilibrium attained by the capacitor at constant output and at constant ambient air
temperature
3.24
residual voltage
voltage remaining on the terminals of a capacitor at a certain time following disconnection
4 Service conditions
4.1 Normal service conditions
This standard gives requirements for capacitors intended for use under the following
conditions:
a) Residual voltage at energization
Not to exceed 10 % rated voltage (Clause 22, Clause 32, and Annex B).
b) Altitude
Not exceeding 2 000 m.
c) Ambient air temperature categories
Capacitors are classified in temperature categories, each category being specified by a
number followed by a letter. The number represents the lowest ambient air temperature at
which the capacitor may operate.
The letters represent upper limits of temperature variation ranges, having maximum values
specified in Table 1. The temperature categories cover the temperature range of –50 °C to
+55 °C.
– 12 – 60831-1 © IEC:2014
The lowest ambient air temperature at which the capacitor may be operated should be chosen
from the five preferred values +5 °C, –5 °C, –25 °C, –40 °C, –50 °C.
For indoor use, a lower limit of –5 °C is normally applicable.
Table 1 is based on service conditions in which the capacitor does not influence the ambient
air temperature (for example outdoor installations).
Table 1 – Letter symbols for upper limit of temperature range
Ambient temperature
°C
Symbol
Highest mean over any period of
Maximum
24 h 1 year
A 40 30 20
B 45 35 25
C 50 40 30
D 55 45 35
NOTE 1 The temperature values according to Table 1 can be found in the
meteorological temperature table covering the installation site.
NOTE 2 Higher temperature values than those indicated in Table 1 can be
considered in special applications by mutual agreement between manufacturer and
purchaser. In that case, the temperature category should be indicated by the
combination of minimum and maximum temperature values, for example, –40/60.

If the capacitor influences the air temperature, the ventilation and/or choice of capacitor shall
be such that the Table 1 limits are maintained. The cooling air temperature in such an
installation shall not exceed the temperature limits of Table 1 by more than 5 °C.
Any combination of minimum and maximum values can be chosen for the standard
temperature category of a capacitor, for example –40/A or –5/C.
Preferred temperature categories are:
–40/A, –25/A, –5/A and –5/C.
4.2 Unusual service conditions
Unless otherwise agreed between manufacturer and purchaser, this standard does not apply
to capacitors, the service conditions of which, in general, are incompatible with the require-
ments of the present standard.
5 Test requirements
5.1 General
Clause 5 gives the test requirements for capacitor units and, when specified, for capacitor
elements.
Supporting insulators, switches, instrument transformers, fuses, etc, shall be in accordance
with relevant IEC standards.
60831-1 © IEC:2014 – 13 –
5.2 Test conditions
Unless otherwise specified for a particular test or measurement, the temperature of the
capacitor dielectric at the start of the test shall be in the range of +5 °C to +35 °C.
It may be assumed that the dielectric temperature is the same as the ambient temperature,
provided that the capacitor has been left in an unenergized state at constant ambient
temperature for an adequate period.
The a.c. tests and measurements shall be carried out at a frequency of 50 Hz or 60 Hz inde-
pendent of the rated frequency of the capacitor, if not otherwise specified.
Capacitors having a rated frequency below 50 Hz shall be tested and measured at 50 Hz or
60 Hz, if not otherwise specified.
6 Classification of tests
6.1 Routine tests
The following tests are routine tests. For details, reference should be made to the relevant
clauses or subclauses:
a) capacitance measurement and output calculation (see Clause 7);
b) measurement of the tangent of the loss angle (tan δ) of the capacitor (see Clause 8);
c) voltage test between terminals (see 9.1);
d) voltage test between terminals and container (see 10.1);
e) test of the internal discharge device (see Clause 11);
f) sealing test (see Clause 12).
Routine tests shall have been carried out by the manufacturer on every capacitor before
delivery. If the purchaser so requests, he shall be supplied with a certificate detailing the
results of such tests.
In general, the indicated sequence of the tests is not mandatory.
6.2 Type tests
The following tests are type tests. For details, reference should be made to the relevant
clauses or subclauses:
a) thermal stability test (see Clause 13);
b) measurement of the tangent of the loss angle (tan δ) of the capacitor at elevated
temperature (see Clause 14);
c) voltage test between terminals (see 9.2);
d) voltage test between terminals and container (see 10.2);
e) lightning impulse voltage test between terminals and container (see Clause 15);
f) discharge test (see Clause 16);
g) ageing test (see Clause 17);
h) self-healing test (see Clause 18);
i) destruction test (see Clause 19).
Type tests are carried out in order to ascertain that, as regards design, size, materials and
construction, the capacitor complies with the specified characteristics and operation
requirements detailed in this standard.

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Unless otherwise specified, every capacitor sample to which the type test is applied shall first
have withstood satisfactorily the application of all the routine tests.
The type tests shall have been carried out by the manufacturer, and the purchaser shall,
on request, be supplied with a certificate detailing the results of such tests.
The successful completion of each type test is also valid for units having the same rated
voltage and lower output, provided that they do not differ in any way that may influence the
properties to be checked by the test. It is not essential that all type tests be carried out on the
same capacitor sample.
The number of samples for the type test shall be subjected to agreement between the
manufacturer and user.
6.3 Acceptance tests
Some or all of the routine and/or type tests may be repeated by the manufacturer in
connection with any contract by agreement with the purchaser. The kind of tests, the number
of samples that may be subjected to such repeated tests, and the acceptance criteria shall be
subject to agreement between manufacturer and purchaser, and shall be stated in the
contract.
7 Capacitance measurement and output calculation
7.1 Measuring procedure
The capacitance shall be measured at the voltage and at the frequency chosen by
the manufacturer. The method used shall not include errors due to harmonics, or to acces-
sories external to the capacitor to be measured, such as reactors and blocking circuits in the
measuring circuit. The accuracy of the measuring method and the correlation with the values
measured at rated voltage and frequency shall be given.
The capacitance measurement shall be carried out after the voltage test between terminals
(see Clause 9).
Measurement at a voltage between 0,9 and 1,1 times the rated voltage, and at a frequency
between 0,8 and 1,2 times the rated frequency, shall be performed on the capacitor
previously used for the thermal stability test (see Clause 13), the ageing test (see Clause 17),
and the self-healing test (see Clause 18), and could be performed on other capacitors at the
request of the purchaser in agreement with the manufacturer.
7.2 Capacitance tolerances
The capacitance shall not differ from the rated capacitance by more than
–5 % to +10 % for units and banks up to 100 kvar;
–5 % to +5 % for units and banks above 100 kvar.
The capacitance value is that measured under the conditions of 7.1.
In three-phase units, the ratio of maximum to minimum value of the capacitance measured
between any two-line terminals shall not exceed 1,08.
NOTE A formula for the calculation of the output of a three-phase capacitor from a single-phase capacitance
measurement is given in Annex B.

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