SIST EN IEC 60077-4:2020

SLOVENSKI STANDARD
01-september-2020
Nadomešča:
SIST EN 60077-4:2003
Železniške naprave - Električna oprema za vozna sredstva - 4. del: Elektrotehnične
komponente - Pravila za močnostna stikala za izmenični tok
Railway applications - Electric equipment for rolling stock - Part 4: Electrotechnical
components - Rules for AC circuit-breakers
Bahnanwendungen - Elektrische Betriebsmittel auf Bahnfahrzeugen - Teil 4:
Elektrotechnische Bauteile - Regeln für AC-Leistungsschalter
Applications ferroviaires - Equipements électriques pour le matériel roulant - Partie 4:
Composants électrotechniques - Règles pour disjoncteurs à courant monophasé
Ta slovenski standard je istoveten z: EN IEC 60077-4:2019
ICS:
29.120.50 Varovalke in druga Fuses and other overcurrent
nadtokovna zaščita protection devices
29.280 Električna vlečna oprema Electric traction equipment
45.060.01 Železniška vozila na splošno Railway rolling stock in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60077-4

NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2019
ICS 45.060.01 Supersedes EN 60077-4:2003 and all of its amendments
and corrigenda (if any)
English Version
Railway applications - Electric equipment for rolling stock - Part
4: Electrotechnical components - Rules for AC circuit-breakers
(IEC 60077-4:2019)
Applications ferroviaires - Équipements électriques du Bahnanwendungen - Elektrische Betriebsmittel auf
matériel roulant - Partie 4: Composants électrotechniques - Fahrzeugen - Teil 4: Elektrotechnische Bauteile - Regeln für
Règles pour disjoncteurs à courant monophasé AC-Leistungsschalter
(IEC 60077-4:2019) (IEC 60077-4:2019)
This European Standard was approved by CENELEC on 2019-11-29. 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 60077-4:2019 E

European foreword
The text of document 9/2538/FDIS, future edition 2 of IEC 60077-4, prepared by IEC/TC 9 "Electrical
equipment and systems for railways" was submitted to the IEC-CENELEC parallel vote and approved
by CENELEC as EN IEC 60077-4:2019.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2020-08-29
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2022-11-29
document have to be withdrawn
This document supersedes EN 60077-4:2003 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.

Endorsement notice
The text of the International Standard IEC 60077-4:2019 was approved by CENELEC as a European
Standard without any modification.

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 60060-1 2010 High-voltage test techniques - Part 1: EN 60060-1 2010
General definitions and test requirements
IEC 60077-1 2017 Railway applications - Electric equipment EN 60077-1 2017
for rolling stock - Part 1: General service
conditions and general rules
IEC 60077-2 2017 Railway applications - Electric equipment EN 60077-2 2017
for rolling stock - Part 2: Electrotechnical
components - General rules
IEC 60529 -  Degrees of protection provided by - -
enclosures (IP Code)
IEC 61373 -  Railway applications - Rolling stock EN 61373 -
equipment - Shock and vibration tests
IEC 62271-1 2017 High-voltage switchgear and controlgear - EN 62271-1 2017
Part 1: Common specifications for
alternating current switchgear and
controlgear
IEC 62271-100 2008 High-voltage switchgear and controlgear - EN 62271-100 2009
Part 100: Alternating current circuit-
breakers
+ A1 2012  + A1 2012
+ A2 2017  + A2 2017
IEC 62271-102 -  High-voltage switchgear and controlgear -- - -
Part 102: Alternating current disconnectors
and earthing switches
IEC 60077-4 ®
Edition 2.0 2019-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Railway applications – Electric equipment for rolling stock –

Part 4: Electrotechnical components – Rules for AC circuit-breakers

Applications ferroviaires – Équipements électriques du matériel roulant –

Partie 4: Composants électrotechniques – Règles pour disjoncteurs

à courant monophasé
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 45.060.01 ISBN 978-2-8322-7508-5

– 2 – IEC 60077-4:2019 © IEC 2019
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 7
3.1 Components . 7
3.2 Component parts . 8
3.3 Operational features . 9
3.4 Making and breaking characteristics . 10
3.5 Abbreviated terms . 12
4 Classification . 12
5 Characteristics . 13
5.1 Summary of characteristics . 13
5.2 Type of circuit-breaker . 13
5.3 Rated values and limiting values for the main circuit . 13
5.3.1 General . 13
5.3.2 Rated voltages . 13
5.3.3 Rated currents . 13
5.3.4 Rated operational frequency . 14
5.3.5 Rated power factors. 14
5.3.6 Short-circuit characteristics . 14
5.4 Operational frequencies . 16
5.5 Electric and pneumatic control circuits . 16
5.6 Electric and pneumatic auxiliary circuits . 17
5.7 Overcurrent release . 17
5.8 Recovery voltages . 17
6 Product information . 17
6.1 Component documentation . 17
6.2 Marking . 17
7 Normal service conditions . 17
8 Constructional and performance requirements . 17
8.1 Constructional requirements . 17
8.2 Performance requirements . 18
8.2.1 Operating conditions . 18
8.2.2 Temperature limits . 18
8.2.3 Operation following inactivity . 18
8.2.4 Electromagnetic compatibility (EMC) . 18
8.2.5 Acoustic noise emission . 18
8.2.6 Clearances . 18
8.2.7 Creepage distances . 18
8.2.8 Switching overvoltages . 18
8.2.9 Operational performance capability . 18
8.2.10 Ability to withstand vibration and shock . 19
8.2.11 Ability to make and break under short-circuit conditions . 19
9 Tests . 19
9.1 Kind of tests . 19

IEC 60077-4:2019 © IEC 2019 – 3 –
9.1.1 General . 19
9.1.2 Type tests . 20
9.1.3 Routine tests . 20
9.1.4 Investigation tests . 20
9.2 Verification of constructional requirements . 20
9.2.1 General . 20
9.2.2 Type tests . 20
9.2.3 Routine tests . 20
9.3 Type tests for verification of performance requirements . 20
9.3.1 Test sequences . 20
9.3.2 General test conditions . 21
9.3.3 Test sequence I: General performance characteristics . 22
9.3.4 Test sequence II: Rated short-circuit making and breaking capacities . 23
9.3.5 Test sequence III: Ability to withstand vibration and shock . 25
9.3.6 Test sequence IV: Climatic conditions . 26
9.3.7 Test sequence V: Other tests . 26
9.4 Routine tests for verification of performance requirements . 26
9.4.1 General . 26
9.4.2 Functional test . 26
9.4.3 Calibration of releases . 27
9.4.4 Air-tightness (for pneumatic circuit-breaker) . 27
9.4.5 Dielectric withstand . 27
Annex A (informative) Test circuit to verify the making and breaking capacities . 28
Annex B (informative) Determination of short-circuit making and breaking currents,
and of percentage DC component . 29
Bibliography . 30

Figure A.1 – Diagram of the test circuit . 28
Figure B.1 – Determination of short-circuit making and breaking currents, and of
percentage DC components . 29

Table 1 – Standard values of transient recovery voltage – Representation by two
parameters . 16
Table 2 – Operational performance capability . 19
Table 3 – List of type test sequences for performance requirements . 21
Table 4 – Tolerances on test values . 22
Table 5 – Standard values of prospective transient recovery voltage – Representation
by two parameters . 24

– 4 – IEC 60077-4:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
RAILWAY APPLICATIONS –
ELECTRIC EQUIPMENT FOR ROLLING STOCK –

Part 4: Electrotechnical components –
Rules for AC circuit-breakers
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 60077-4 has been prepared by IEC technical committee 9:
Electrical equipment and systems for railways.
This second edition cancels and replaces the first edition, issued in 2003. It constitutes a
technical revision.
This edition includes the following main technical changes with regard to the previous edition:
a) standard values of transient recovery voltages and test procedure are reviewed;
b) procedure of verification of temperature rise is changed;
c) air-tightness test as type test, insulation resistance measurement are added.

IEC 60077-4:2019 © IEC 2019 – 5 –
The text of this International Standard is based on the following documents:
FDIS Report on voting
9/2538/FDIS 9/2554/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 document should be read in conjunction with IEC 60077-1 and IEC 60077-2.
A list of all parts in the IEC 60077 series, published under the general title Railway
applications – Electric equipment for rolling stock, 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.
– 6 – IEC 60077-4:2019 © IEC 2019
RAILWAY APPLICATIONS –
ELECTRIC EQUIPMENT FOR ROLLING STOCK –

Part 4: Electrotechnical components –
Rules for AC circuit-breakers
1 Scope
In addition to the general requirements of IEC 60077-2, this part of IEC 60077 gives rules for
AC circuit-breakers, the main contacts of which are connected to AC overhead contact lines;
the nominal voltage of these circuits being in accordance with IEC 60850.
This document, together with IEC 60077-2, states specifically:
a) the characteristics of the circuit-breakers;
b) the service conditions with which circuit-breakers comply with reference to:
– operation and behaviour in normal service;
– operation and behaviour in short-circuit;
– dielectric properties;
c) the tests for confirming the compliance of the components with the characteristics under
the service conditions and the methods to be adopted for these tests;
d) the information to be marked on, or given with the circuit-breaker.
NOTE 1 Circuit-breakers which are dealt with in this document can be provided with devices for automatic
opening under pre-determined conditions other than those of overcurrent, for example, undervoltage and reversal
of power flow direction. This document does not deal with the verification of operation under such predetermined
conditions.
NOTE 2 The incorporation of electronic components or electronic sub-assemblies into electrotechnical compo-
nents is now common practice.
Although this document is not applicable to electronic equipment, the presence of electronic components does not
provide a reason to exclude such electrotechnical components from the scope.
Electronic sub-assemblies included in the circuit-breakers comply with the relevant standard for electronics
(IEC 60571).
NOTE 3 Certain of these rules, after agreement between the user and the manufacturer, are used for
electrotechnical components installed on vehicles other than rail rolling stock such as mine locomotives,
trolleybuses, etc. In this case, particular additional requirements can be necessary.
This document does not cover industrial circuit-breakers which comply with IEC 62271-100.
For these, in order to ensure satisfactory operation, this document is used to specify only the
particular requirements for rolling stock. In such cases, a specific document states the
additional requirements with which the industrial circuit-breakers comply, for example:
– either to be adapted (e.g. for control voltage, environmental conditions, etc.);
– or to be installed and used so that they do not have to endure specific rolling stock
conditions;
– or to be additionally tested to prove that these components can withstand satisfactorily the
rolling stock conditions.
IEC 60077-4:2019 © IEC 2019 – 7 –
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.
IEC 60060-1:2010, High-voltage test techniques – Part 1: General definitions and test
requirements
IEC 60077-1:2017, Railway applications – Electric equipment for rolling stock. – Part 1:
General service conditions and general rules
IEC 60077-2:2017, Railway applications – Electric equipment for rolling stock. – Part 2:
Electrotechnical components – General rules
IEC 60529, Degrees of protection provided by enclosures (IP Code)
IEC 61373, Railway applications – Rolling stock equipment – Shock and Vibration tests
IEC 62271-1:2017, High-voltage switchgear and controlgear – Part 1: Common specifications
for alternating current switchgear and controlgear
IEC 62271-100:2008, High-voltage switchgear and controlgear – Part 100: Alternating current
circuit-breakers
IEC 62271-100:2008/AMD1:2012
IEC 62271-100:2008/AMD2:2017
IEC 62271-102, High-voltage switchgear and controlgear – Part 102: Alternating current
disconnectors and earthing switches
3 Terms, definitions and abbreviated terms
For the purposes of this document, the terms and definitions given in Clause 3 of
IEC 60077-1:2017 and Clause 3 of IEC 60077-2:2017, and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 Components
3.1.1
indoor circuit-breaker
circuit-breaker designed solely for protected installation against wind, rain, snow, abnormal
dirt deposits, abnormal conditions, ice and hoarfrost
3.1.2
outdoor circuit-breaker
circuit-breaker suitable for installation in open air, i.e. capable of withstanding wind, rain,
snow, dirt deposits, condensation, ice and hoarfrost

– 8 – IEC 60077-4:2019 © IEC 2019
3.1.3
oil circuit-breaker
circuit-breaker in which the contacts open and close in oil
Note 1 to entry: Typical examples of oil circuit-breakers are live tank minimum oil circuit-breakers and dead tank
bulk oil circuit-breakers.
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-14-28]
3.1.4
vacuum circuit-breaker
circuit-breaker in which the contacts open and close within a highly evacuated envelope
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-14-29]
3.1.5
air-blast circuit-breaker,
circuit-breaker in which the contacts open in a blast of air
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-14-32, modified – “gas-blast” has been
deleted. “the gas used is air” has been replaced with “the contacts open in a blast of air”.]
3.1.6
air circuit-breaker
circuit-breaker in which the contacts open and close in air
3.1.7
gas circuit-breaker
circuit-breaker in which the contacts open and close in a gas other than air at atmospheric or
higher pressure
Note 1 to entry: An example of a gas circuit-breaker is the sulphur hexafluoride circuit-breaker.
3.1.8
semiconductor circuit-breaker
circuit-breaker designed to make and break the current in an electric circuit by means of the
controlled conductivity of a semiconductor
Note 1 to entry: There can be mechanical contacts associated with these semiconductor devices.
[SOURCE: IEC 60050-811:2017, 811-29-42]
3.2 Component parts
3.2.1
release,
device which releases the holding means and permits the opening or closing of the circuit-
breaker
Note 1 to entry: A circuit-breaker can be activated by several releases each becoming operational according to
specified conditions.
Note 2 to entry: These releases can be mechanically or electrically connected to the switching device.
[SOURCE: IEC 60050-811:2017, 811-29-44]
3.2.2
overcurrent release
release which permits a mechanical switching device to open with or without time-delay when
the current in the release exceeds a predetermined value

IEC 60077-4:2019 © IEC 2019 – 9 –
Note 1 to entry: This value can in some cases depend upon the rate-of-rise of current.
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-16-33]
3.2.3
definite time-delay overcurrent release
overcurrent release which operates with a definite time-delay, which may be adjustable, but is
independent of the value of the overcurrent
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-16-34]
3.2.4
direct overcurrent release
overcurrent release directly energised by the current in the main circuit of a mechanical
switching device
[SOURCE: IEC 60050-441:1984/AMD1:2000,441-16-36]
3.2.5
indirect overcurrent release,
overcurrent release initiated by the current in the main circuit of a mechanical switching
device through a current sensor
[SOURCE: IEC 60050-441:1984/AMD1:2000,441-16-37, modified – “energized” and “a current
transformer or a shunt” have been replaced with ”initiated” and “a current sensor”.]
3.2.6
anti-pumping device
device which prevents reclosing after a close-open operation as long as the device initiating
closing is maintained in the position for closing
Note 1 to entry: The opening operation may be either an opening command or a tripping operation.
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-16-48, modified – Note 1 to entry has been
added.]
3.2.7
enclosure,
part of an assembly providing a specified degree of protection of equipment against external
influences and a specified degree of protection against approach to or contact with live parts
and against contact with moving parts
Note 1 to entry: The enclosure may also provide a protection of adjacent parts against the influence of the circuit-
breaker (for example, arcing).
[SOURCE: IEC 60050-441:1984/AMD1:2000,441-13-01, modified – Note 1 to entry has been
added.]
3.2.8
integral enclosure
enclosure forming an integral part of the circuit-breaker
3.3 Operational features
3.3.1
trip-free circuit-breaker
circuit-breaker, the moving main contacts of which return to and remain in the open position
when the opening (i.e. tripping) operation is initiated after the initiation of the closing
operation even if the closing command is maintained

– 10 – IEC 60077-4:2019 © IEC 2019
Note 1 to entry: To ensure proper breaking of the current which may have been established, it may be necessary
that the contacts momentarily reach the closed position.
Note 2 to entry: The trip free operation may require an anti-pumping device.
3.3.2
current setting,
value of the operating current for which the release is adjusted and in accordance with which
its operating conditions are defined
Note 1 to entry: A release may have more than one current setting.
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-16-46, modified – Note 1 to entry has been
added.]
3.3.3
current setting range,
range between the minimum and maximum values over which the current setting of the
release can be adjusted
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-16-47]
3.3.4
tripping operation
opening operation of a circuit-breaker initiated by a release
3.4 Making and breaking characteristics
NOTE See Annex B.
3.4.1
opening time,
interval of time between the specified instant of initiation of the opening operation and the
instant when the arcing contacts have separated in all poles
Note 1 to entry: The instant of initiation of the opening operation is specified by the manufacturer for all the
opening commands other than overcurrent.
Note 2 to entry: The opening time includes the operating time of any auxiliary equipment necessary to open the
circuit-breaker and forming an integral part of the circuit-breaker.
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-36, modified – Note 1 to entry has been
modified and Note 2 to entry has been added.]
3.4.2
prospective current,
current that would flow in the circuit if each pole of the switching device or the fuse were
replaced by a conductor of negligible impedance
Note 1 to entry: This term is commonly associated with fault conditions.
Note 2 to entry: The prospective current is composed of an RMS AC value plus a DC component (if any).
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-01, modified – Notes to entry have been
replaced.]
3.4.3
prospective peak current
peak value of a prospective current during the transient period following initiation
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-02, modified – Note has been deleted.]

IEC 60077-4:2019 © IEC 2019 – 11 –
3.4.4
prospective symmetrical current,
prospective current when it is initiated at such an instant that no transient phenomenon
follows the initiation
Note 1 to entry: The prospective symmetrical current is expressed by its RMS value.
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-03, modified – Note 1 has been deleted.]
3.4.5
breaking current,
current in a pole of a switching device or in a fuse at the instant of initiation of the arc during a
breaking process
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-07]
3.4.6
breaking capacity,
value of prospective current that a switching device or a fuse is capable of breaking at a
stated voltage under prescribed conditions of use and behaviour
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-08, modified – Notes have been deleted.]
3.4.7
making capacity,
value of prospective making current that a switching device is capable of making at a stated
voltage under prescribed conditions of use and behaviour
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-09, modified – Note has been deleted.]
3.4.8
short-circuit making capacity
making capacity for which the prescribed conditions include a short-circuit at the terminals of
the switching device
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-10]
3.4.9
short-circuit breaking capacity
breaking capacity for which the prescribed conditions include a short-circuit at the terminals of
the switching device
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-11]
3.4.10
short-time withstand current
current that a circuit or a switching device in the closed position can carry during a specified
short time under specified conditions of use and behaviour
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-17]
3.4.11
peak withstand current
value of peak current that a circuit or a switching device in the closed position can withstand
under prescribed conditions of use and behaviour
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-18]

– 12 – IEC 60077-4:2019 © IEC 2019
3.4.12
recovery voltage
voltage which appears across the terminals of a pole of a switching device or a fuse after the
breaking of the current
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-25, modified – Note has been deleted.]
3.4.13
transient recovery voltage
recovery voltage during the time in which it has a significant transient character
Note 1 to entry: The transient recovery voltage may be oscillatory or non-oscillatory or a combination of these
depending on the characteristics of the circuit and the switching device.
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-26, modified – The second sentence of
Note 1 to entry has been deleted. Note 2 to entry has been deleted.]
3.4.14
prospective transient recovery voltage,
transient recovery voltage following the breaking of the prospective symmetrical current by an
ideal switching device
Note 1 to entry: The definition assumes that the switching device or the fuse, for which the prospective transient
recovery voltage is sought, is replaced by an ideal switching device, i.e. having instantaneous transition from zero
to infinite impedance at the very instant of zero current, i.e. at the "natural" zero. For circuits where the current can
follow several different paths, e.g. a polyphase circuit, the definition further assumes that the breaking of the
current by the ideal switching device takes place only in the pole considered.
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-29]
3.4.15
power-frequency recovery voltage
recovery voltage after the transient voltage phenomena have subsided
[SOURCE: IEC 60050-441:1984/AMD1:2000, 441-17-27]
3.5 Abbreviated terms
AC Alternating Current
DC Direct Current
EMC Electromagnetic Compatibility
RMS Root Mean Square (value)
RRRV Rate of Rise of Recovery Voltage
TRV Transient Recovery Voltage
4 Classification
This clause is intended to list the characteristics of a circuit-breaker on which information is
given by the manufacturer and which shall be verified by testing where relevant.
The circuit-breakers are classified:
– according to their operational frequency C1, C2 or C3. The characteristics of these
operational frequencies are given in 5.4;
– according to the type of design, i.e. outdoor or indoor circuit-breaker;
– according to the degree of protection provided by the enclosure (see IEC 60529).

IEC 60077-4:2019 © IEC 2019 – 13 –
5 Characteristics
5.1 Summary of characteristics
The characteristics of a circuit-breaker shall be stated in terms of the following, as applicable:
– type of circuit-breaker (5.2);
– rated values and limiting values for the main circuit (5.3);
– operational frequencies (5.4);
– electric and pneumatic control circuits (5.5);
– electric and pneumatic auxiliary circuits (5.6);
– overcurrent release (5.7);
– peak value of the recovery voltage (5.8).
5.2 Type of circuit-breaker
It is necessary to state:
– the kind of device (e.g. air-blast circuit-breaker, air circuit-breaker, vacuum circuit-breaker,
gas circuit-breaker, oil circuit-breaker, semiconductor circuit-breaker, etc.);
– the type of design (see Clause 4);
– the degree of protection provided by the enclosure (see Clause 4);
– operational features (e.g. trip-free circuit-breaker direct or indirect overcurrent release,
time-delay overcurrent release).
5.3 Rated values and limiting values for the main circuit
5.3.1 General
Rated values are assigned by the manufacturer but it is not necessary to establish all the
ratings listed.
5.3.2 Rated voltages
A component is defined by the following rated voltages given in 5.2 of IEC 60077-1:2017:
– rated operational voltage (U );
r
NOTE 1 A circuit-breaker has more than one rated operational voltage or has a rated operational voltage range.
– rated insulation voltage (U );
Nm
NOTE 2 When no rated insulation voltage has been assigned to a circuit-breaker, the rated insulation voltage is
considered to be equal to the highest value of the rated operational voltage.
– rated impulse voltage (U );
Ni
– power-frequency test voltage (U ).
a
5.3.3 Rated currents
A component is defined by the following rated currents given in 5.4 of IEC 60077-1:2017 and
5.3.3 of IEC 60077-2:2017:
– rated operational current (I ) at the rated power factor T2 (see 5.3.5);
r
NOTE 1 A circuit-breaker can have more than one rated operational current or can have a rated operational
current range.
– conventional free air thermal current (I );
th
– conventional free air thermal current for DC (I );
th_DC
– 14 – IEC 60077-4:2019 © IEC 2019
NOTE 2 The conventional free air thermal current for DC is the maximum value of the DC test current to be used
for temperature rise tests of equipment in free air at the maximum ambient air temperature.
NOTE 3 AC circuit-breaker used for AC-DC dual system electric rolling stock can have a different thermal current
for DC. For DC system only conducing performance is relevant.
– conventional enclosed thermal current (I );
the
– rated short-time withstand current (I );
cw
– rated peak withstand current (I ).
P
NOTE 4 Where the circuit-breaker is used to energize and protect a transformer or an inductor or a reactive filter
circuit, the inrush of current on energization can contain a large and prolonged DC component.
5.3.4 Rated operational frequency
The rated operational frequency (f ) of a circuit-breaker is the frequency relevant to the rated
r
operational voltage (see 5.5 of IEC 60077-1:2017).
A circuit-breaker may have more than one rated operational frequency.
5.3.5 Rated power factors
The rated power factors are used to characteristize the performance as follows:
– 0,1 for short-circuit conditions (T1);
– 0,8 for normal service conditions (T2).
The rated power factor for the short-circuit is dependent on the electrical characteristics of the
sub-station, the supply lines to the vehicle and the load.
If necessary, other power factor values may be defined by agreement between the
manufacturer and the user.
5.3.6 Short-circuit characteristics
5.3.6.1 Rated peak withstand current
The rated peak withstand current (I ) is the peak current associated with the first major loop
P
of the rated short-time withstand current that the switchgear and controlgear can carry in the
closed position under its service conditions.
The rated peak withstand current is obtained by multiplying the RMS value of the rated short-
time withstand current with a peak factor. This peak factor is a function of the DC time
constant of the network and the rated frequency. The preferred value of the peak factor is 2,5.
5.3.6.2 Rated short-circuit making capacity
The manufacturer shall declare the rated short-circuit making current corresponding to the
power factor T1.
The rated short-circuit making capacity of a circuit-breaker is the peak value (I ) of the
P
making current corresponding to the rated operational voltage. The circuit-breaker shall
satisfy the rated short-circuit making test specified in 9.3.4 and shall be capable of
subsequent operation.
5.3.6.3 Rated short-circuit breaking capacity
The manufacturer shall declare the rated short-circuit breaking current corresponding to the
power factor T1.
IEC 60077-4:2019 © IEC 2019 – 15 –
It is the highest short-circuit current which the circuit-breaker shall be capable of breaking
under the conditions of test specified in this document in a circuit having a power-frequency
recovery voltage corresponding to the rated operational voltage and having a transient
recovery voltage equal to the rated value specified in 5.3.6.4.
T
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