IEC 62610-6:2020

IEC 62610-6 ®
Edition 1.0 2020-03
INTERNATIONAL
STANDARD
Mechanical structures for electrical and electronic equipment – Thermal
management for cabinets in accordance with IEC 60297 and IEC 60917 series –
Part 6: Air recirculation and bypass of indoor cabinets
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IEC 62610-6 ®
Edition 1.0 2020-03
INTERNATIONAL
STANDARD
Mechanical structures for electrical and electronic equipment – Thermal

management for cabinets in accordance with IEC 60297 and IEC 60917 series –

Part 6: Air recirculation and bypass of indoor cabinets

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.240 ISBN 978-2-8322-8006-5

– 2 – IEC 62610-6:2020 © IEC 2020
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Recirculation level . 8
5 Determination of recirculation and bypass ratio . 9
5.1 Cooling airflow in a cabinet . 9
5.2 Recirculation ratio of a subrack . 10
5.3 Recirculation ratio of a cabinet . 11
5.4 Bypass ratio of a cabinet . 11
6 Measurement of recirculation and bypass . 11
6.1 Measurement of recirculation of a subrack . 11
6.2 Measurement of recirculation of a cabinet . 12
6.3 Measurement of bypass of a cabinet . 12
6.4 Measurement methods of temperature . 12
6.4.1 Intake air temperature of a subrack . 12
6.4.2 Intake air temperature of a subrack group . 13
6.4.3 Exhaust air temperature of a subrack . 13
6.4.4 Exhaust air temperature of a subrack group . 13
6.4.5 Intake air temperature of a cabinet . 13
6.4.6 Exhaust air temperature of a cabinet . 13
6.5 Measurement method of recirculation for an empty cabinet . 14
Annex A (normative) Measurement method of recirculation with dummy thermal loads . 15
A.1 Purpose . 15
A.2 Specifications . 15
A.2.1 DTL . 15
A.2.2 Cabinet specifications . 15
A.2.3 Measurement configurations . 16
A.3 Environmental conditions . 16
A.4 Measurement positions . 16
A.4.1 Intake air temperature of DTL . 16
A.4.2 Exhaust air temperature of DTL . 16
A.4.3 Intake air temperature of a cabinet . 16
A.4.4 Exhaust air temperature of a cabinet . 16
A.4.5 Evaluation of recirculation ratio of a subrack . 16
A.4.6 Evaluation of recirculation and bypass ratio of a cabinet . 16
A.5 Case study . 16
A.6 Relationship between recirculation ratio and intake temperature rise . 19
Annex B (normative) Derivation of recirculation and bypass in a cabinet . 21
B.1 General . 21
B.2 Derivation of recirculation and bypass . 21
Annex C (informative) Application of recirculation and bypass to outdoor cabinets . 22
C.1 General . 22
C.2 Application example . 22
Bibliography . 24

Figure 1 – Airflow in a cabinet . 9
Figure 2 – Diagram of cabinet airflows . 10
Figure A.1 – Outline drawings of DTL . 17
Figure A.2 – Experimental setup of a cabinet and DTL . 17
Figure A.3 – Measurement points of intake air temperature of DTL . 18
Figure A.4 – Measurement points of exhaust air temperature of DTL . 18
Figure A.5 – Measurement points of intake air temperature of a cabinet . 18
Figure A.6 – Measurement points of exhaust air temperature of a cabinet . 18
Figure A.7 – Recirculation ratio vs intake air temperature rise. 20
Figure C.1 – Outdoor cabinet airflow schematic . 23
Figure C.2 – Airflow diagram and air temperature in outdoor cabinet . 23

Table 1 – Recirculation level . 9
Table A.1 – Specifications of DTL . 15
Table A.2 – Specifications of DTL . 17
Table A.3 – Test result . 19
Table A.4 – Recirculation and bypass ratio of a cabinet . 19
Table C.1 – A case study of an outdoor cabinet . 23

– 4 – IEC 62610-6:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MECHANICAL STRUCTURES FOR ELECTRICAL AND ELECTRONIC
EQUIPMENT – THERMAL MANAGEMENT FOR CABINETS IN
ACCORDANCE WITH IEC 60297 AND IEC 60917 SERIES –

Part 6: Air recirculation and bypass of indoor cabinets

FOREWORD
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International Standard IEC 62610-6 has been prepared by subcommittee 48D: Mechanical
structures for electrical and electronic equipment, of IEC technical committee 48: Electrical
connectors and mechanical structures for electrical and electronic equipment.
The text of this International Standa
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