ISO/IEC 22237-3:2021

INTERNATIONAL ISO/IEC
STANDARD 22237-3
First edition
2021-10
Information technology — Data centre
facilities and infrastructures —
Part 3:
Power distribution
Technologie de l’information — Installation et infrastructures de
centres de traitement de données —
Partie 3: Distribution de puissance
Reference number
© ISO/IEC 2021
© ISO/IEC 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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© ISO/IEC 2021 – All rights reserved

Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 2
3.1 Terms and definitions . 2
3.2 Abbreviated terms . 6
3.3 Symbols . 6
4 Conformance . 7
5 Power supply and distribution within data centres . 7
5.1 Functional elements. 7
5.1.1 General . 7
5.1.2 Power supply to the data centre . 8
5.1.3 Power distribution within the data centre . 9
5.2 Dimensioning of power distribution systems . 10
6 Availability .11
6.1 General requirements . 11
6.2 Power supply . 11
6.2.1 Capacity planning . 11
6.2.2 Availability of the utility supply . 13
6.2.3 Power quality . 14
6.2.4 Load presented to the utility supply. 15
6.2.5 Equipment . 15
6.2.6 Availability Class design options . 17
6.3 Power distribution .23
6.3.1 Capacity planning . 23
6.3.2 Power quality . 24
6.3.3 Equipment . 25
6.3.4 Availability Class design options . 25
6.4 Incorporation of low voltage direct current distribution .29
6.5 Additional considerations . 29
6.5.1 Residual current measurement .29
6.5.2 Lightning and surge protection .29
6.5.3 Segregation of power distribution cabling and information technology
cabling . 30
6.6 Emergency power off (EPO). 30
6.6.1 Requirements .30
6.6.2 Recommendations.30
7 Physical security .30
7.1 General .30
7.2 Access. 30
7.2.1 Power supply . .30
7.2.2 Power distribution .30
7.2.3 Attachment of unauthorized end-equipment .30
7.3 Internal environmental events . 31
7.3.1 Power supply . . 31
7.3.2 Power distribution . 31
7.4 External environmental events . 31
8 Energy efficiency enablement and power distribution .31
8.1 General . 31
8.2 Granularity Level 1 . 32
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© ISO/IEC 2021 – All rights reserved

8.2.1 Requirements . 32
8.2.2 Recommendations.33
8.3 Granularity Level 2 . 33
8.3.1 Requirements . 33
8.3.2 Recommendations. 33
8.4 Granularity Level 3 .34
8.4.1 Requirements .34
8.4.2 Recommendations.34
8.5 Cabling infrastructure to support energy efficiency enablement .34
Bibliography .35
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© ISO/IEC 2021 – All rights reserved

Foreword
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accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives or
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This document was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 39, Sustainability, IT & Data Centres.
This first edition cancels and replaces th
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