SIST EN 60931-1:1999

SLOVENSKI STANDARD
SIST EN 60931-1:1999
01-julij-1999
Shunt power capacitors of the non-self-healing type for a.c. systems having a
rated voltage up to and including 1 kV - Part 1: General - Performance, testing and
rating - Safety requirements - Guide for installation and operation (IEC 60931-
1:1996)
Shunt power capacitors of the non-self-healing type for a.c. systems having a rated
voltage up to and including 1 kV -- Part 1: General - Performance, testing and rating -
Safety requirements - Guide for installation and operation
Nichtselbstheilende Leistungs-Parallelkondensatoren für Wechselstromanlagen mit einer
Nennspannung bis 1 kV -- Teil 1: Allgemeines - Leistungsanforderungen, Prüfung und
Bemessung - Sicherheitsanforderungen - Anleitung für Errichtung und Betrieb
Condensateurs shunt de puissance non autorégénérateurs pour réseaux à courant
alternatif de tension assignée inférieure ou égale à 1 kV -- Partie 1: Généralités -
Caractéristiques fonctionnelles, essais et valeurs assignées - Règles de sécurité - Guide
d'installation et d'exploitation
Ta slovenski standard je istoveten z: EN 60931-1:1996
ICS:
31.060.70 0RþQRVWQLNRQGHQ]DWRUML Power capacitors
SIST EN 60931-1:1999 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN 60931-1:1999

---------------------- Page: 2 ----------------------

SIST EN 60931-1:1999

---------------------- Page: 3 ----------------------

SIST EN 60931-1:1999

---------------------- Page: 4 ----------------------

SIST EN 60931-1:1999

---------------------- Page: 5 ----------------------

SIST EN 60931-1:1999

---------------------- Page: 6 ----------------------

SIST EN 60931-1:1999
NORME CEI
INTERNATIONALE IEC
931-1
INTERNATIONAL
Deuxième édition
STANDARD
Second edition
1996-11
Condensateurs shunt de puissance non
autorégénérateurs 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
Shunt power capacitors of the non-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
© CEI 1996 Droits de reproduction réservés — Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni
No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun pro-
any form or by any means, electronic or mechanical,
cédé, électronique ou mécanique, y compris la photocopie et
including photocopying and microfilm, without permission
les microfilms, sans l'accord écrit de l'éditeur. in writing from the publisher.
Bureau Central de la Commission Electrotechnique Internationale 3, rue de Varembé Genève, Suisse
Commission Electrotechnique Internationale CODE PRIX `,
International Electrotechnical Commission V
PRICE CODE
MemAyHapomaa 3nenrporexHHVecnaa I{oMHCCHa
IEC
• Pour prix,
• voir catalogue en vigueur
For price, see current catalogue

---------------------- Page: 7 ----------------------

SIST EN 60931-1:1999
931-1 © IEC:1996
CONTENTS
Page
FOREWORD 7
SECTION 1: GENERAL
Clause
1 Scope and object 9
11
2 Normative references
13
3 Definitions
17
4 Service conditions
SECTION 2: QUALITY REQUIREMENTS AND TESTS
5 Test requirements 19
6 Classification of tests 21
23
7 Capacitance measurement and output calculation
23
8 Measurement of the tangent of the loss angle (tan 8) of the capacitor
25
9 Voltage tests between terminals
25
10 Voltage tests between terminals and container
29
11 Test of internal discharge device
12 Sealing test 29
13 Thermal stability test 29
14 Measurement of the tangent of the loss angle (tan 8) of the capacitor at elevated
33
temperature
33
15 Lightning impulse voltage test between terminals and container
33
16 Discharge test
35
17 Ageing test
35
18 Self-healing test
35
19 Destruction test
SECTION 3: OVERLOADS
35
20 Maximum permissible voltage
37
21 Maximum permissible current
SECTION 4: SAFETY REQUIREMENTS
22 Discharge device 39
39
23 Container connections
39
24 Protection of the environment
39
25 Other safety requirements

---------------------- Page: 8 ----------------------

SIST EN 60931-1:1999
931-1 ©IEC:1996 – 5 –
Clause Page
SECTION 5: MARKINGS
26 Marking of the unit 41
27 Marking of the bank 43
SECTION 6: GUIDE FOR INSTALLATION AND OPERATION
28 General 43
45
29 Choice of the rated voltage
47
30 Operating temperature
49
31 Special service conditions
32 Overvoltages 49
33 Overload currents 51
34 Switching and protective devices and connections 53
35 Choice of creepage distance 55
36 Capacitors connected to systems with audio-frequency remote control 55
37 Electromagnetic compatibility (EMC) 57
Annexes
A Additional definitions, requirements and tests for power filter capacitors 61
B Formulae for capacitors and installations 65

---------------------- Page: 9 ----------------------

SIST EN 60931-1:1999
931-1 © IEC:1996 — 7 —
INTERNATIONAL ELECTROTECHNICAL COMMISSION
SHUNT POWER CAPACITORS OF THE NON-SELF-HEALING TYPE
FOR AC 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
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 cooperation 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 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 931-1 has been prepared by IEC technical committee 33:
Power capacitors.
This second edition cancels and replaces the first edition published in 1989 and its
amendment 1 (1991), and constitutes a technical revision.
The text of this standard is based on the following documents:
FDIS Report on voting
33/235/FDIS
33/250/RVD
33/235A/FDIS
Full information on the voting for the approval of this standard can be found in the report
on voting indicated in the above table.
Annexe A forms an integral part of this standard.
Annex B is for information only.

---------------------- Page: 10 ----------------------

SIST EN 60931-1:1999
931-1 © IEC:1996 - 9 -
SHUNT POWER CAPACITORS
OF THE NON-SELF-HEALING TYPE
FOR AC 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
Section 1: General
1 Scope and object
This part of IEC 931 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 1000 V and frequencies 15 Hz to 60 Hz.
This part of IEC 931 also applies to capacitors intended for use in power filter circuits.
Additional definitions, requirements, and tests for filter capacitors are given in annex A.
Additional requirements for capacitors protected by internal element fuses, as well as
requirements for the same, are given in IEC 931-3.
The following capacitors are excluded from this part of IEC 931:
-
Shunt power capacitors of the self-healing type for a.c. systems having a rated volt-
age up to and including 1000 V (IEC 831).
- Shunt capacitors for a.c. power systems having a rated voltage above 1000 V
(IEC 871).
- Capacitors for inductive heat-generating plants operating at frequencies between
40 Hz and 24 000 Hz (IEC 110).
Series capacitors (IEC 143).
- Capacitors for motor applications and the like (IEC 252).
- Coupling capacitors and capacitor dividers (IEC 358).
- Capacitors to be used in power electronic circuits (IEC 1071).
- Small a.c. capacitors to be used for fluorescent and discharge lamps (IEC 1048 and
IEC 1049).
- 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., are to be in
accordance with the relevant IEC standards.

---------------------- Page: 11 ----------------------

SIST EN 60931-1:1999
- 11 -
931-1 ©IEC:1996
a) to formulate uniform rules regarding performances, testing and rating;
b) to formulate specific safety rules;
c) to provide a guide for installation and operation.
2 Normative references
The following normative documents contains provisions which, through reference in this
text, constitute provisions of this part of IEC 931. At the time of publication, the editions
indicated were valid. All normative documents are subject to revision, and parties to
agreements based on this part of IEC 931 are encouraged to investigate the possibility of
applying the most recent editions of the normative documents indicated below. Members
of IEC and ISO maintain registers of currently valid International Standards.
IEC 50(436): 1990, International Electrotechnical Vocabulary (lEV) - Chapter 436: Power
capacitors
IEC 60-1: 1989, High voltage test techniques - Part 1: General definitions and test
requirements
IEC 110: 1973, Recommendation for capacitors for inductive heat generating plants
operating at frequencies between 40 and 24 000 Hz
IEC 143: 1992, Series capacitors for power systems
A.C. motor capacitors
IEC 252: 1993,
IEC 269-1: 1986, Low-voltage fuses - Part 1: General requirements
IEC 358: 1990, Coupling capacitors and capacitor dividers
IEC 831-1: 1996, 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
IEC 871-1: 1987, Shunt capacitors for a.c. power systems having a rated voltage above
1000 V* - Part 1: General - Performance, testing and rating - Safety requirements -
Guide for installation and operation
IEC 931-2: 1995, Shunt power capacitors of the non-self-healing type for a.c. systems
having a rated voltage up to and including 1000 V - Part 2: Ageing test and destruction
test
* According to Amendment No. 1 (1991).

---------------------- Page: 12 ----------------------

SIST EN 60931-1:1999
931-1 ©IEC:1996 - 13 -
IEC 931-3: 1996, Shunt power capacitors of the non-self-healing type for a.c. systems
having a rated voltage up to and including 1000 V - Pa
rt 3: Internal fuses
IEC 1000-2-2: 1990, Electromagnetic compatibility (EMC) - Part 2: Environment -
Section 2: Compatibility levels for low-frequency conducted disturbances and signalling in
public low-voltage power supply systems
IEC 1000-4-1: 1992, Electromagnetic compatibility (EMC) - Part 4: Testing and measure-
ment techniques - Section 1: Overview of immunity tests - Basic EMC publication
IEC 1048: 1991, Capacitors for use in tubular fluorescent and other discharge lamp
circuits - General and safety requirements
IEC 1049: 1991, Capacitors for use in tubular fluorescent and other discharge lamp
circuits - Performance requirements
IEC 1071-1: 1993, Power electronic capacitors - Part 1: General
3 Definitions
For the purpose of this part of IEC 931, the following definitions apply:
3 1 capacitor element (or element): A device consisting essentially of two electrodes
separated by a dielectric. [IEV 436-01-03]
3.2 capacitor unit (or unit): An assembly of one or more capacitor elements in the
same container with terminals brought out. [IEV 436-01-04]
3.3 non-self-healing capacitor: A capacitor in which the dielectric, after local break-
down, is not restored.
3.4 capacitor bank (or bank): A number of capacitor units connected so as to act
together. [IEV 436-01-06]
3.5 capacitor: In this part of IEC 931, the word capacitor is used when it is not neces-
sary to lay particular stress upon the different meanings of the words capacitor unit or
capacitor bank.
One or more capacitor banks and their accessories.
3.6 capacitor installation:
[IEV 436-01-07]
3.7 discharge device of a capacitor: A device which may be incorporated in a capaci-
tor, capable of reducing the voltage between the terminals practically to zero, within a
given time, after the capacitor has been disconnected from a network. [IEV 436-03-15
modified]

---------------------- Page: 13 ----------------------

SIST EN 60931-1:1999
931-1 ©IEC:1996 –15 –
3.8 internal fuse of a capacitor: A fuse connected inside a capacitor unit, in series
with an element or a group of elements. [IEV 436-03-16]
3.9 overpressure disconnector for a capacitor:
A disconnecting device designed
to switch off the capacitor in the case of abnormal increase of the internal pressure.
[IEV 436-03-17 modified]
3.10 overtemperature disconnector for a capacitor:
A disconnecting device designed
to switch off the capacitor in the case of abnormal increase of the internal temperature.
3.11
line terminal: A terminal intended for connection to a line conductor of a network.
[IEV 436-03-01]
NOTE – In polyphase capacitors, a terminal intended to be connected to the neutral conductor is not con-
sidered to be a line terminal.
3.12
rated capacitance of a capacitor (CN): The capacitance value for which the
capacitor has been designed. [IEV 436-01-12 modified]
3.13
rated output of a capacitor (O N): The reactive power derived from the rated
values of capacitance, frequency and voltage. [IEV 436-01-16 modified]
3.14 rated voltage of a capacitor (U N): The r.m.s. value of the alternating voltage for
which the capacitor has been designed. [IEV 436-01-15]
NOTE – 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), UN refers to the rated
voltage of each circuit.
For polyphase capacitors with internal electrical connections between the phases, and for polyphase capaci-
tor banks, UN refers to the phase-to-phase voltage.
3.15 rated frequency of a capacitor (fN): The frequency for which the capacitor has
been designed. [IEV 436-01-14]
3.16 rated current of a capacitor (IN):
The r.m.s. value of the alternating current for
which the capacitor has been designed. [IEV 436-01-13]
3.17
capacitor losses: The active power dissipated in the capacitor. [IEV 436-04-10]
NOTE – 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.
3.18
tangent of the loss angle (tan 6) of a capacitor: The ratio between the equivalent
series resistance and the capacitive reactance of the capacitor at specified sinusoidal
alternating voltage and frequency. [IEV 436-04-11]
3.19 maximum permissible a.c. voltage of a capacitor: The maximum r.m.s. alter-
nating voltage which the capacitor can sustain for a given time in specified conditions.
[IEV 436-04-07]
3.20 maximum permissible a.c. current of a capacitor: The maximum r.m.s. alter-
nating current which the capacitor can sustain for a given time in specified conditions.
[IEV 436-04-09]

---------------------- Page: 14 ----------------------

SIST EN 60931-1:1999
931-1 ©IEC:1996 - 17 -
3.21 ambient air temperature:
The temperature of the air at the proposed location of
the capacitor.
3.22 cooling air temperature:
The temperature of the cooling air measured at the
hottest position in the bank, under steady-state conditions, midway between two units. 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: The 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 in the following con-
ditions:
a)
Residual voltage at energization
Not to exceed 10 % rated voltage (clause 22, clause 32, and annex B).
b) Altitude
Not exceeding 2000 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.
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
Maximuum
24 h 1 year
A 40 30 20
B 45 35 25
C 50 40 30
45
D 55 35

---------------------- Page: 15 ----------------------

SIST EN 60931-1:1999
931-1 ©IEC:1996 - 19 -
NOTES
1 The temperature values according to table 1 can be found in the meteorological temperature table cover-
ing the installation site.
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
requirements of the present standard.
Section 2: Quality requirements and tests
5 Test requirements
5.1 General
This clause 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.
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 tempera-
ture, provided that the capacitor has been left in an unenergized state at constant ambient
temperature for an adequate period. When a correction has to be applied, the reference
temperature to be used is +20 °C, unless otherwise agreed between the manufacturer and
the purchaser.
The a.c. tests and measurements shall be carried out at a frequency of 50 Hz or 60 Hz
independent of the rated frequency of the capacitor, if not otherwise specified.

---------------------- Page: 16 ----------------------

SIST EN 60931-1:1999
931-1 © IEC:1996 – 21 –
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
The tests are classified as:
6.1
Routine tests
a) Capacitance measurement and output calculation (see clause 7).
Measurement of the tangent of the loss angle (tan S) of the capacitor
b)
(see clause 8).
c) Voltage test between terminals (see 9.1).
d) Voltage test between terminals and container (see 10.1).
Test of the internal discharge device (see clause 11).
e)
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
a) Thermal stability test (see clause 13).
b) Measurement of the tangent of the loss angle (tan 8) 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).
Lightning impulse voltage test between terminals and container (see clause 15).
e)
f) Discharge test (see clause 16).
g) Ageing test (see clause 17).
h) Self-healing test (see clause 18). Not applicable.
i) Destruction test (see clause 19).
j)
Disconnecting test on internal fuses (see IEC 931-3, subclause 5.3).
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.
Unless otherwise specified, every capacitor sample to which it is intended to apply the
type test 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.

---------------------- Page: 17 ----------------------

SIST EN 60931-1:1999
Oo
- 23 -
931-1 IEC:1996
6.3 Acceptance tests
The routine and/or type tests, or some of them, 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 used
for the thermal stability test (see clause 13) and the ageing test (see clause 17) before
these tests, and may be performed on other capacitors on 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 +15 % for units and banks up to 100 kvar;
0 % to +10 % 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 calculation of the output of a three-phase capacitor from single-phase capacitance
measurement is given in annex B.
8 Measurement of the tangent of the loss angle (tan S) of the capacitor
8.1 Measuring procedure
The capacitor losses (or tan 6) 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 accessories 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.

---------------------- Page: 18 ----------------------

SIST EN 60931-1:1999
931-1 ©IEC:1996 - 25 -
The measurement of the capacitor losses 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 before
the thermal stability test (see clause 13), and may be performed on other capacitors on
request of the purchaser in agreement with the manufacturer.
NOTES
1 When testing a large number of capacitors, statistical sampling may be used for measuring tan S. The
statistical sampling plan should be by agreement between manufacturer and purchaser.
2 The tan S value of certain types of dielectric is a function of the energization time before the measure-
ment. In that case, test voltage and energization time should be by agreement between manufacturer and
purchaser.
8.2 Loss requirements
The value of tan 5, measured in accordance with 8.1, shall not exceed the value declared
by the manufacturer for the temperature and voltage of the test, or the value agreed upon
between manufacturer and purchaser.
9 Voltage tests between terminals
9.1
Routine test
Every capacitor shall be subjected for 10 s to either the test in item a) or the test in
item b). If no prior agreement is reached, the choice is left to the manufacturer. During the
test, neither puncture nor flashover shall occur.
a) An a.c. test, the test voltage being:
Ut =2,15 UN
The a.c. test shall be carried out with a substantially sinusoidal voltage.
b)
A d.c. test, the test voltage being:
Ut =4,3 UN
NOTES
1 For polyphase capacitors, the test voltages should be adjusted as appropriate.
2 Operation of internal element fuses is permitted, provided the capacitance tolerances are still met and
that not more than two fuses have operated per unit.
9.2 Type test
Already performed during the routine test according to 9.1. Refer also to the third para-
graph of 6.2.
10 Voltage tests between terminals and container
10.1 Routine test
Units having all terminals insulated from the container shall be subjected to an a.c. voltage
applied between the terminals (joined together) and the container. If the rated voltage of
the capacitor is UN <_660 V, the voltage to be applied is 3 kV for 10 s or 3,6 kV for a

---------------------- Page: 19 ----------------------

SIST EN 60931-1:1999
– 27 –
931-1 © IEC:1996
minimum time of 2 s. If the rated voltage of the capacitor is
UN >660 V, the voltage to be
applied is 6 kV for 10 s or 7,2 kV for a minimum time of 2 s.
During the test, neither puncture nor flashover shall occur.
The test shall be performed, even if, in service, one of the terminals is intended to be
connected to the container.
Three-phase units having separate phase capacitance can be tested with respect to the
container with all the terminals joined together. Units having one terminal permanently
connected to the container shall not be subjected to this test.
When the unit container consists of insulating material, this test shall be omitted.
If a capacitor has separate phases or sections, a test of the insulation between phases or
sections shall be made at the same voltage value as for the terminals-to-container test.
10.2 Type test
Units having all terminals insulated from the co
...