EN 60137:2017

SLOVENSKI STANDARD
01-februar-2018
1DGRPHãþD
SIST EN 60137:2008
,]ROLUDQLVNR]QMLNL]DL]PHQLþQHQDSHWRVWLQDG9
Insulated bushings for alternating voltages above 1 000 V
Isolierte Durchführungen für Wechselspannungen über 1 000 V
Traversées isolées pour tensions alternatives supérieures à 1 000 V
Ta slovenski standard je istoveten z: EN 60137:2017
ICS:
29.080.20 Skoznjiki Bushings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 60137
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2017
ICS 29.080.20 Supersedes EN 60137:2008
English Version
Insulated bushings for alternating voltages above 1 000 V
(IEC 60137:2017)
Traversées isolées pour tensions alternatives supérieures à Isolierte Durchführungen für Wechselspannungen über
1 000 V 1 000 V
(IEC 60137:2017) (IEC 60137:2017)
This European Standard was approved by CENELEC on 2017-07-27. 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, 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: Avenue Marnix 17, B-1000 Brussels
© 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 60137:2017 E
European foreword
The text of document 36A/187/FDIS, future edition 7 of IEC 60137, prepared by SC 36A "Insulated
Bushings" of IEC/TC 36 "Insulators" was submitted to the IEC-CENELEC parallel vote and approved
by CENELEC as EN 60137:2017.
The following dates are fixed:
• latest date by which the document has to be (dop) 2018-05-17
implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2020-11-17
• latest date by which the national
standards conflicting with the
document have to be withdrawn
This document supersedes EN 60137:2008.

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 60137:2017 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:

IEC 60076-1 NOTE Harmonized as EN 60076-1.
IEC 60076-2 NOTE Harmonized as EN 60076-2.
IEC 60076-3 NOTE Harmonized as EN 60076-3.
IEC 60507 NOTE Harmonized as EN 60507.
IEC 60836 NOTE Harmonized as EN 60836.
IEC 60867 NOTE Harmonized as EN 60867.
IEC 62271-203:2011 NOTE Harmonized as EN 62271-203:2012 (not modified).
IEC 62271-211:2014 NOTE Harmonized as EN 62271-211:2014 (not modified).
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year

IEC 60038 (mod) -  IEC standard voltages EN 60038 -
IEC 60050-212 2010 International Electrotechnical Vocabulary - - -
Part-212: Electrical insulating solids, liquids
and gases
IEC 60059 -  IEC standard current ratings EN 60059 -
IEC 60060-1 -  High-voltage test techniques - Part 1: EN 60060-1 -
General definitions and test requirements
IEC 60068-2-17 1994 Basic environmental testing procedures - EN 60068-2-17 1994
Part 2-17: Tests - Test Q: Sealing
IEC 60071-1 -  Insulation co-ordination - Part 1: Definitions, EN 60071-1 -
principles and rules
IEC 60076-5 -  Power transformers - Part 5: Ability to EN 60076-5 -
withstand short circuit
IEC 60076-7 -  Power transformers - Part 7: Loading guide - -
for oil-immersed power transformers
IEC 60216-2 -  Electrical insulating materials - Thermal EN 60216-2 -
endurance properties - Part 2: Determination
of thermal endurance properties of electrical
insulating materials - Choice of test criteria
IEC 60270 -  High-voltage test techniques - Partial EN 60270 -
discharge measurements
IEC 60296 -  Fluids for electrotechnical applications - EN 60296 -
Unused mineral insulating oils for
transformers and switchgear
IEC 60376 -  Specification of technical grade sulfur EN 60376 -
hexafluoride (SF6) for use in electrical
equipment
IEC 60422 -  Mineral insulating oils in electrical equipment EN 60422 -
- Supervision and maintenance guidance
IEC 60480 -  Guidelines for the checking and treatment of EN 60480 -
sulphur hexafluoride (SF6) taken from
electrical equipment and specification for its
re-use
IEC 60505 -  Evaluation and qualification of electrical EN 60505 -
insulation systems
IEC 61099 -  Insulating liquids - Specifications for unused EN 61099 -
synthetic organic esters for electrical
purposes
IEC 61462 -  Composite hollow insulators - Pressurized EN 61462 -
and unpressurized insulators for use in
electrical equipment with rated voltage
greater than 1 000 V - Definitions, test
methods, acceptance criteria and design
recommendations
IEC 62155 (mod) 2003 Hollow pressurized and unpressurized EN 62155 2003
ceramic and glass insulators for use in
electrical equipment with rated voltages
greater than 1 000 V
IEC 62217 -  Polymeric HV insulators for indoor and EN 62217 -
outdoor use - General definitions, test
methods and acceptance criteria
IEC 62271-1 -  High-voltage switchgear and controlgear - EN 62271-1 -
Part 1: Common specifications
IEC Guide 109 -  Environmental aspects - Inclusion in - -
electrotechnical product standards
IEC/TS 60815-1 -  Selection and dimensioning of high-voltage - -
insulators intended for use in polluted
conditions - Part 1: Definitions, information
and general principles
IEC/TS 60815-2 -  Selection and dimensioning of high-voltage - -
insulators intended for use in polluted
conditions - Part 2: Ceramic and glass
insulators for a.c. systems
IEC/TS 60815-3 -  Selection and dimensioning of high-voltage - -
insulators intended for use in polluted
conditions - Part 3: Polymer insulators for
a.c. systems
CISPR 16-1 series Specification for radio disturbance and EN 55016-1 series
immunity measuring apparatus and methods
CISPR 18-2 -  Radio interference characteristics of - -
overhead power lines and high-voltage
equipment - Part 2: Methods of
measurement and procedure for determining
limits
IEC TS 61463 -  Bushings - Seismic qualification - -

IEC 60137 ®
Edition 7.0 2017-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Insulated bushings for alternating voltages above 1 000 V

Traversées isolées pour tensions alternatives supérieures à 1 000 V

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.080.20 ISBN 978-2-8322-4417-3

– 2 – IEC 60137:2017  IEC 2017
CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 10
3 Terms and definitions . 12
4 Ratings . 18
4.1 Rated highest voltage for equipment (U ) . 18
m
4.2 Rated current (I ) . 18
r
4.3 Rated thermal short-time current (I ) . 18
th
4.4 Rated dynamic current (I ) . 19
d
4.5 Minimum withstand values of cantilever load . 19
4.6 Angle of mounting . 20
4.7 Minimum nominal creepage distance . 20
4.8 Temperature limits and temperature rise . 20
4.9 Insulation levels . 20
4.10 Test tap on transformer bushings . 23
5 Operating conditions . 23
5.1 Temporary overvoltages. 23
5.2 Altitude . 24
5.3 Temperature of ambient air and immersion media . 25
5.4 Seismic conditions . 25
5.5 Very fast transients (VFT) . 26
5.6 Transformer insulating liquid . 26
6 Ordering information and markings . 26
6.1 Enumeration of characteristics . 26
6.1.1 General . 26
6.1.2 Application . 26
6.1.3 Classification of bushings . 26
6.1.4 Ratings . 26
6.1.5 Operating conditions . 27
6.1.6 Design . 27
6.2 Markings . 28
7 Test requirements . 29
7.1 General requirements . 29
7.2 Test classification . 30
7.2.1 General . 30
7.2.2 Type tests . 30
7.2.3 Routine tests . 31
7.2.4 Special tests . 32
7.3 Condition of bushings during dielectric and thermal tests . 32
8 Type tests . 34
8.1 General . 34
8.2 Dry or wet power-frequency voltage withstand test . 34
8.2.1 Applicability . 34
8.2.2 Test method and requirements . 34

IEC 60137:2017  IEC 2017 – 3 –
8.2.3 Acceptance . 34
8.3 Long duration power-frequency voltage withstand test (ACLD) . 34
8.3.1 Applicability . 34
8.3.2 Test method and requirements . 34
8.3.3 Acceptance . 35
8.4 Dry lightning impulse voltage withstand test . 35
8.4.1 Applicability . 35
8.4.2 Test method and requirements . 35
8.4.3 Acceptance . 36
8.5 Dry or wet switching impulse voltage withstand test . 36
8.5.1 Applicability . 36
8.5.2 Test method and requirements . 36
8.5.3 Acceptance . 37
8.6 Thermal stability test . 37
8.6.1 Applicability . 37
8.6.2 Test method and requirements . 38
8.6.3 Acceptance . 38
8.7 Electromagnetic compatibility tests (EMC) . 38
8.7.1 Emission test . 38
8.7.2 Immunity test . 40
8.8 Temperature rise test . 40
8.8.1 Applicability . 40
8.8.2 Test method and requirements . 40
8.8.3 Acceptance . 41
8.9 Verification of thermal short-time current withstand . 41
8.9.1 Applicability . 41
8.9.2 Verification method and requirements . 41
8.9.3 Acceptance . 42
8.10 Cantilever load withstand test . 42
8.10.1 Applicability . 42
8.10.2 Test method and requirements . 42
8.10.3 Acceptance . 43
8.11 Tightness test on liquid-filled, compound-filled and liquid-insulated bushings . 43
8.11.1 Applicability . 43
8.11.2 Test method and requirements . 43
8.11.3 Acceptance . 44
8.12 Internal pressure test on gas-filled, gas-insulated and gas-impregnated
bushings . 44
8.12.1 Applicability . 44
8.12.2 Test method and requirements . 44
8.12.3 Acceptance . 44
8.13 External pressure test on partly or completely gas-immersed bushings . 44
8.13.1 Applicability . 44
8.13.2 Test method and requirements . 44
8.13.3 Acceptance . 44
8.14 Verification of dimensions . 44
8.14.1 Applicability . 44
8.14.2 Acceptance . 45
9 Routine tests . 45

– 4 – IEC 60137:2017  IEC 2017
9.1 General . 45
9.2 Measurement of dielectric dissipation factor (tan δ) and capacitance at
ambient temperature . 45
9.2.1 Applicability . 45
9.2.2 Test method and requirements . 45
9.2.3 Acceptance . 45
9.3 Dry lightning impulse voltage withstand test . 46
9.3.1 Applicability . 46
9.3.2 Test method and requirements . 46
9.3.3 Acceptance . 46
9.4 Dry power-frequency voltage withstand test . 46
9.4.1 Applicability . 46
9.4.2 Test method and requirements . 47
9.4.3 Acceptance . 47
9.5 Measurement of partial discharge quantity . 47
9.5.1 Applicability . 47
9.5.2 Test method and requirements . 47
9.5.3 Acceptance . 47
9.6 Tests of tap insulation . 48
9.6.1 Applicability and test requirements . 48
9.6.2 Acceptance . 48
9.7 Internal pressure test on gas-filled, gas-insulated and gas-impregnated
bushings . 49
9.7.1 Applicability . 49
9.7.2 Test method and requirements . 49
9.7.3 Acceptance . 49
9.8 Tightness test on liquid-filled, compound-filled and liquid-insulated bushings . 49
9.8.1 Applicability . 49
9.8.2 Test method and requirements . 49
9.8.3 Acceptance . 49
9.9 Tightness test on gas-filled, gas-insulated and gas-impregnated bushings . 49
9.9.1 Applicability . 49
9.9.2 Test method and requirements . 50
9.9.3 Acceptance . 50
9.10 Tightness test at the flange or other fixing device . 50
9.10.1 Applicability . 50
9.10.2 Test method and requirements . 50
9.10.3 Acceptance . 51
9.11 Visual inspection and dimensional check . 51
9.11.1 Applicability . 51
9.11.2 Acceptance . 51
10 Requirements and tests for non-capacitance graded bushings of rated highest

voltages for equipment up to and including 52 kV . 51
10.1 General . 51
10.2 Temperature requirements . 51
10.3 Level of immersion medium. 51
10.4 Markings . 51
10.5 Test requirements . 52
10.5.1 General . 52

IEC 60137:2017  IEC 2017 – 5 –
10.5.2 Type tests . 52
10.5.3 Routine tests . 52
11 Recommendations for transport, storage, erection, operation and maintenance . 53
11.1 General . 53
11.2 Conditions during transport, storage and installation . 53
11.3 Installation . 53
11.4 Unpacking and lifting . 53
11.5 Assembly . 54
11.5.1 General . 54
11.5.2 Mounting . 54
11.5.3 Connections . 54
11.5.4 Final installation inspection . 54
11.6 Operation . 55
11.7 Maintenance . 55
11.7.1 General . 55
11.7.2 Recommendation for the manufacturer . 55
11.7.3 Recommendations for the user . 56
11.7.4 Failure report . 56
12 Safety . 57
12.1 General . 57
12.2 Electrical aspects . 57
12.3 Mechanical aspects . 57
12.4 Thermal aspects . 58
13 Environmental aspects . 58
Annex A (informative) Determination of the hottest spot in bushings with conductors
embedded in the insulation material . 59
Bibliography . 60

or m on the co-ordination switching impulse withstand voltage . 24
Figure 1 – Fact
Figure 2 – Marking plate for bushings for rated highest voltage for equipment (U )
m
greater than 100 kV . 29
Figure 3 – Marking plate for bushings for rated highest voltage for equipment (U )
m
equal to or less than 100 kV, except for bushings for which Figure 4 is applicable . 29
Figure 4 – Marking plate for bushings for rated highest voltage for equipment (U )
m
equal to or less than 52 kV made of ceramic, glass or inorganic materials, resin or
combined insulation (see 10.3) . 29
Figure 5 – Voltage profile for long duration test . 35

Table 1 – Minimum values of cantilever withstand load (see 4.5 and 8.10) . 19
Table 2 – Maximum values of temperature and temperature rise above ambient air
(see 4.8) . 21
Table 3 – Insulation levels for highest voltage for equipment (U ) (see 4.9, 8.2, 8.4,
m
8.5, 9.3 and 9.4) . 22
Table 4 – Temperature of ambient air and immersion media . 25
Table 5 – Applicability of type tests (see 7.2.2, excluding bushings according to
Clause 10) . 31
Table 6 – Applicability of routine tests (see 7.2.3, excluding bushings according to
Clause 10) . 32

– 6 – IEC 60137:2017  IEC 2017
Table 7 – Correction of test voltages (see 7.3) . 33
Table 8 – Maximum values of tan δ and tan δ increase (see 9.2) . 46
Table 9 – Maximum values of partial discharge quantity (see 8.3 and 9.5) . 48
Table 10 – Applicability of type tests for bushings according to Clause 10 (see 10.5.1). 52
Table 11 – Applicability of routine tests for bushings according to Clause 10 (see
10.5.3) . 53

IEC 60137:2017  IEC 2017 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INSULATED BUSHINGS FOR ALTERNATING
VOLTAGES ABOVE 1 000 V
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 60137 has been prepared by sub-committee 36A: Insulated
bushings, of IEC technical committee 36: Insulators.
This seventh edition cancels and replaces the sixth edition, published in 2008, and constitutes
a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
• Resin-impregnated synthetic (RIS) bushings has been introduced.
≤ 1,1 kV, U = 1 100 kV and U = 1 200 kV have been introduced.
• Bushings with U
m m m
• Temperature rise testing has been included for liquid-insulated bushings according to
clause to 3.4.
• Introducing dry lightning impulse testing as a routine test for all transformer bushings with
U > 72,5 kV.
m
• The altitude correction procedure has been revised ( > 1 000 m).

– 8 – IEC 60137:2017  IEC 2017
• An explanation about Very Fast Transient (VFT) phenomenon and its impact on bushings
has been included.
The text of this International Standard is based on the following documents:
FDIS Report on voting
36A/187/FDIS 36A/189/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.
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.
IEC 60137:2017  IEC 2017 – 9 –
INTRODUCTION
In the preparation of the current edition of this standard further consideration has been given
to the test requirements for power transformers as described in IEC 60076-3:2013.

– 10 – IEC 60137:2017  IEC 2017
INSULATED BUSHINGS FOR ALTERNATING
VOLTAGES ABOVE 1 000 V
1 Scope
This International Standard specifies the characteristics and tests for insulated bushings.
This standard is applicable to bushings, as defined in Clause 3, intended for use in electrical
apparatus, machinery, transformers, switchgear and installations for three-phase alternating
current systems, having highest voltage for equipment above 1 000 V and power frequencies
of 15 Hz up to and including 60 Hz.
Subject to special agreement between purchaser and supplier, this standard may be applied,
in part or as a whole, to the following:
• bushings used in other than three-phase systems;
• bushings for high-voltage direct current systems;
• bushings for testing transformers;
• bushings for capacitors.
Special requirements and tests for transformer bushings in this standard apply also to reactor
bushings.
This standard is applicable to bushings made and sold separately. Bushings which are a part
of an apparatus and which cannot be tested according to this standard should be tested with
the apparatus of which they form part.
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 60038, IEC standard voltages
IEC 60050-212:2010, International Electrotechnical Vocabulary – Part 212: Electrical
insulating solids, liquids and gases
IEC 60059, IEC standard current ratings
IEC 60060-1, High-voltage test techniques – Part 1: General definitions and test requirements
IEC 60068-2-17:1994, Basic environmental testing procedures – Part 2-17: Tests – Test Q:
Sealing
IEC 60071-1, Insulation co-ordination – Part 1: Definitions, principles and rules
IEC 60076-5, Power transformers – Part 5: Ability to withstand short circuit
IEC 60076-7, Power transformers – Part 7: Loading guide for oil-immersed power
transformers
IEC 60137:2017  IEC 2017 – 11 –
IEC 60216-2, Electrical insulating materials – Thermal endurance properties – Part 2:
Determination of thermal endurance properties of electrical insulating materials – Choice of
test criteria
IEC 60270, High-voltage test techniques – Partial discharge measurements
IEC 60296, Fluids for electrotechnical applications – Unused mineral insulating oils for
transformers and switchgear
IEC 60376, Specification of technical grade sulfur hexafluoride (SF ) for use in electrical
equipment
IEC 60422, Mineral insulating oils in electrical equipment – Supervision and maintenance
guidance
IEC 60480, Guidelines for the checking and treatment of sulfur hexafluoride (SF ) taken from
electrical equipment and specification for its re-use
IEC 60505, Evaluation and qualification of electrical insulation systems
IEC TS 60815-1, Selection and dimensioning of high-voltage insulators intended for use in
polluted conditions – Part 1: Definitions, information and general principles
IEC TS 60815-2, Selection and dimensioning of high-voltage insulators intended for use in
polluted conditions – Part 2: Ceramic and glass insulators for a.c. systems
IEC TS 60815-3, Selection and dimensioning of high-voltage insulators intended for use in
polluted conditions – Part 3: Polymer insulators for a.c. systems
IEC 61099, Insulating liquids – Specifications for unused synthetic organic esters for electrical
purposes
IEC 61462, Composite hollow insulators – Pressurized and unpressurized insulators for use in
electrical equipment with rated voltage greater than 1 000 V – Definitions, test methods,
acceptance criteria and design recommendations
IEC TS 61463, Bushings – Seismic qualification
IEC 62155:2003, Hollow pressurized and unpressurized ceramic and glass insulators for use
in electrical equipment with rated voltages greater than 1 000 V
IEC 62217, Polymeric HV insulators for indoor and outdoor use – General definitions, test
methods and acceptance criteria
IEC 62271-1, High-voltage switchgear and controlgear – Part 1: Common specifications
IEC Guide 109, Environmental aspects – Inclusion in electrotechnical product standards
CISPR 16-1 (all parts), Specification for radio disturbance and immunity measuring apparatus
and methods
CISPR 18-2, Radio interference characteristics of overhead power lines and high-voltage
equipment – Parts 2: Methods of measurement and procedure for determining limits

– 12 – IEC 60137:2017  IEC 2017
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
bushing
device that enables one or several conductors to pass through a partition such as a wall or a
tank, and insulates the conductors from it; the means of attachment (flange or fixing device) to
the partition forms part of the bushing
Note 1 to entry: The conductor may form an integral part of the bushing or be drawn into the central tube of the
bushing.
[SOURCE: IEC 60050-471:2007, 471-02-01]
3.2
liquid-filled bushing
bushing in which the space between the inside surface of the insulating envelope and the
solid major insulation is filled with mineral oil or other insulating liquid
3.3
compound-filled bushing
bushing in which the space between the inside surface of the insulating envelope and the
solid major insulation is filled with an insulating compound
3.4
liquid-insulated bushing
bushing in which the major insulation consists of mineral oil or another insulating liquid,
enclosed by an insulating envelope
Note 1 to entry: These bushings are often of an open design which require proper processing after installation in
order to avoid trapped air and subsequent partial discharges during testing or in service.
3.5
gas-filled
...