IEC TS 62271-315:2025

High-voltage switchgear and controlgear - Part 315: Direct current (DC) transfer switches

IEC TS 62271-315:2025 is applicable to direct current (DC) transfer switches designed for indoor or outdoor installation and for operation on HVDC transmission systems having direct voltages of 100 kV and above. DC transfer switches normally include metallic return transfer switches (MRTS), earth return transfer switches (ERTS), neutral bus switches (NBS) and neutral bus earthing switches (NBES).

General Information

• Status: Published
• Publication Date: 10-Mar-2025
• ICS: 29.130.10 - High voltage switchgear and controlgear
• Technical Committee: SC 17A - Switching devices
• Drafting Committee: WG 65 - TC 17/SC 17A/WG 65
• Current Stage: PPUB - Publication issued
• Start Date: 03-Jan-2025
• Due Date: 11-Mar-2025
• Completion Date: 11-Mar-2025

Standards Content (Sample)

IEC TS 62271-315 ®
Edition 1.0 2025-03
TECHNICAL
SPECIFICATION
High-voltage switchgear and controlgear –
Part 315: Direct current (DC) transfer switches

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IEC TS 62271-315 ®
Edition 1.0 2025-03
TECHNICAL
SPECIFICATION
High-voltage switchgear and controlgear –

Part 315: Direct current (DC) transfer switches

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.130.10  ISBN 978-2-8327-0244-4

– 2 – IEC TS 62271-315:2025 © IEC 2025
CONTENTS
FOREWORD . 7
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 10
3.1 General terms and definitions . 10
3.2 Assemblies of switchgear and controlgear . 10
3.3 Parts of assemblies . 10
3.4 Switching devices . 10
3.5 Parts of switchgear and controlgear . 12
3.6 Operational characteristics of DC transfer switches . 13
3.7 Characteristic quantities . 13
3.8 Index of definitions . 14
4 Normal and special service conditions . 15
5 Ratings . 16
5.1 General . 16
5.2 Rated direct voltage (U ) . 16
rd
5.3 Rated insulation level (U , U , U ) . 16
dd p s
5.4 Rated continuous current (I ) . 17
rd
5.5 Rated values of short-time withstand current . 17
5.5.1 Typical waveform of short-circuit current . 17
5.5.2 Rated short-time withstand direct current (I ) . 17
kd
5.5.3 Rated peak withstand current (I ) . 17
pd
5.5.4 Rated duration of short circuit (t ) . 17
kd
5.6 Rated supply voltage of auxiliary and control circuits (U ) . 17
a
5.6.1 General . 17
5.6.2 Rated supply voltage (U ) . 17
a
5.7 Rated supply frequency of auxiliary and control circuits . 17
5.8 Rated pressure of compressed gas supply for controlled pressure systems . 18
5.101 Rated direct voltage of transfer switch (U ) . 18
rts
5.102 Rated transfer current (I ) . 18
t
5.103 Rated commutation voltage (U ) . 18
c
5.104 Rated dissipated energy during transfer operation (E ) . 18
rd
5.105 Rated operating sequence . 19
5.106 Rated open-close time . 19
6 Design and construction . 19
6.1 Requirements for liquids in switchgear and controlgear . 19
6.2 Requirements for gases in switchgear and controlgear . 19
6.3 Earthing of switchgear and controlgear . 19
6.4 Auxiliary and control equipment and circuits . 19
6.5 Dependent power operation . 20
6.6 Stored energy operation . 20
6.7 Independent unlatched operation (independent manual or power operation) . 20
6.8 Manually operated actuators . 20
6.9 Operation of releases . 20

6.10 Pressure/level indication . 20
6.11 Nameplates. 20
6.12 Locking devices . 22
6.13 Position indication . 22
6.14 Degrees of protection by enclosures . 22
6.15 Creepage distances for outdoor insulators . 22
6.16 Gas and vacuum tightness . 22
6.17 Tightness for liquid system . 22
6.18 Fire hazard (flammability) . 22
6.19 Electromagnetic compatibility (EMC) . 22
6.20 X-ray emission . 22
6.21 Corrosion . 22
6.22 Filling levels for insulation, switching and operation . 22
6.101 Seismic requirement for operation . 22
6.102 Commutation switch . 22
6.102.1 General requirement for operation . 22
6.102.2 Pressure limits of fluids for operation. . 23
6.102.3 Vent outlets . 23
6.102.4 Time quantities . 23
6.102.5 Static mechanical loads . 23
6.102.6 Classification . 24
6.102.7 Arcing withstand capability . 24
6.103 Insulated platform . 25
6.104 Commutation capacitor . 25
6.105 Energy dissipation device . 25
6.106 Reactor . 25
6.107 Making switch (if applicable) . 25
6.108 Charging device (if applicable) . 25
7 Type tests . 25
7.1 General . 25
7.1.1 Basics . 25
7.1.2 Information for identification of test objects . 27
7.1.3 Information to be included in type-test reports . 27
7.2 Dielectric tests . 27
7.2.1 General . 27
7.2.2 Ambient air conditions during tests . 27
7.2.3 Wet test procedure . 27
7.2.4 Arrangement of the equipment . 27
7.2.5 Criteria to pass the test . 27
7.2.6 Application of the test voltage and test conditions . 27
7.2.7 Tests of switchgear and controlgear . 28
7.2.8 Artificial pollution tests for outdoor insulators . 29
7.2.9 Partial discharge tests . 29
7.2.10 Dielectric tests on auxiliary and control circuits . 29
7.2.11 Voltage test as condition check . 29
7.3 Resistance measurement . 29
7.3.1 Measurement of the resistance of auxiliary contacts class 1 and class 2. 29
7.3.2 Measurement of the resistance of auxiliary contacts class 3 . 29
7.3.3 Electrical continuity of earthed metallic parts test . 29

– 4 – IEC TS 62271-315:2025 © IEC 2025
7.3.4 Resistance measurement of contacts and connections in the main
circuit as a condition check . 29
7.4 Continuous current tests . 30
7.4.1 Condition of the test object . 30
7.5 Short-time withstand current and pe
...