IEC 62610-6:2020

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

IEC 62610-6:2020 deals with thermal management for cabinets in accordance with IEC 60297 and IEC 60917 series, provides compatible measurement methods of recirculation ratio and bypass ratio which are indicators for defining quality of airflow in the forced air cooling that can be commonly applied to indoor cabinets for mounting subrack and/or chassis-based equipment.
This document contains the following:
a) the definition of recirculation and bypass flow rates in the cooling of the cabinet,
b) the levels of the recirculation ratio RC,
c) the definition of the formula for the recirculation ratio RCs of forced air cooling subrack and/or chassis-based equipment installed in the cabinet,
d) the definition formula of recirculation ratio RCr and bypass rate BPr of the entire cabinet,
e) the requirements of the measuring method of each temperature necessary for calculating the recirculation ratio RCs, RCr and bypass ratio BPr.
The purpose of this document is to provide:
• for the equipment integrator and development designer of the cabinet the criteria for efficiently and correctly determining the specification, and
• for the supplier of the cabinet the measuring and classifying method for the airflow recirculation rate of the subrack and/or chassis-based equipment installed in the cabinet.

Structures mécaniques pour équipements électriques et électroniques - Gestion thermique pour les armoires conformes aux séries IEC 60297 et IEC 60917 - Partie 6: Recyclage et dérivation de l’air des armoires intérieures

IEC 62610-6:2020 traite de la gestion thermique pour les armoires conformément aux séries CEI 60297 et CEI 60917, fournit des méthodes de mesure compatibles du taux de recirculation et du taux de dérivation qui sont des indicateurs pour définir la qualité du flux d'air dans le refroidissement à air forcé qui peuvent être couramment appliquées aux armoires intérieures pour le montage des bacs et / ou des équipements sur châssis.
Ce document contient les éléments suivants:
a) la définition des débits de recirculation et de dérivation dans le refroidissement de l'armoire,
b) les niveaux du taux de recirculation RC,
c) la définition de la formule du taux de recirculation RCs du bac de refroidissement à air forcé et / ou des équipements sur châssis installés dans l'armoire,
d) la formule de définition du taux de recirculation RCr et du taux de dérivation BPr de l'ensemble de l'armoire,
e) les exigences de la méthode de mesure de chaque température nécessaire au calcul du taux de recirculation RCs, RCr et du taux de contournement BPr.
Le but de ce document est de fournir:
• pour l'intégrateur d'équipement et le concepteur de développement de l'armoire les critères pour déterminer efficacement et correctement la spécification, et
• pour le fournisseur de l'armoire, la méthode de mesure et de classification du taux de recirculation du flux d'air d

General Information

• Status: Published
• Publication Date: 24-Mar-2020
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 31.240 - Mechanical structures for electronic equipment
• Technical Committee: SC 48D - Mechanical structures for electrical and electronic equipment
• Drafting Committee: WG 5 - TC 48/SC 48D/WG 5
• Current Stage: PPUB - Publication issued
• Start Date: 30-Mar-2020
• Completion Date: 25-Mar-2020

Standards Content (Sample)

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
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

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3, rue de Varembé [e-mail]
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About the IEC
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International Standards for all electrical, electronic and related technologies.

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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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all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
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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
...

IEC 62610-6 ®
Edition 1.0 2020-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
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

Structures mécaniques pour équipements électriques et électroniques – Gestion
thermique pour les armoires conformes aux séries IEC 60297 et IEC 60917 –
Partie 6: Recyclage et dérivation de l’air des armoires intérieures

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
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The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
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IEC 62610-6 ®
Edition 1.0 2020-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
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

Structures mécaniques pour équipements électriques et électroniques – Gestion

thermique pour les armoires conformes aux séries IEC 60297 et IEC 60917 –

Partie 6: Recyclage et dérivation de l’air des armoires intérieures

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.240 ISBN 978-2-8322-9384-3

– 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
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)”)
...