IEC TS 63346-1-1:2024

IEC TS 63346-1-1 ®
Edition 1.0 2024-12
TECHNICAL
SPECIFICATION
Low-voltage auxiliary power systems –
Part 1-1: Terminology
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IEC TS 63346-1-1 ®
Edition 1.0 2024-12
TECHNICAL
SPECIFICATION
Low-voltage auxiliary power systems –

Part 1-1: Terminology
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 25.040.30; 01.040.01 ISBN 978-2-8327-0078-5

– 2 – IEC TS 63346-1-1:2024 © IEC 2024
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
3.1 Terms and definitions for APS . 6
3.2 Terms and definitions for APS design . 7
3.3 Terms and definitions for APS equipment . 9
3.4 Terms and definitions for APS operation and maintenance . 10
Bibliography . 11

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LOW-VOLTAGE AUXILIARY POWER SYSTEMS –

Part 1-1: Terminology
FOREWORD
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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shall not be held responsible for identifying any or all such patent rights.
IEC TS 63346-1-1 has been prepared by IEC project committee 127: Low-voltage auxiliary
power systems for electric power stations and substations. It is a Technical Specification.
The text of this Technical Specification is based on the following documents:
Draft Report on voting
127/63/DTS 127/68/RVDTS
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Specification is English.

– 4 – IEC TS 63346-1-1:2024 © IEC 2024
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 63346 series, published under the general title Low-voltage auxiliary
power systems, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
INTRODUCTION
The purpose of IEC 63346-1-1 is to present terms and definitions for the publications related to
auxiliary power systems (APSs) including system design, installation and commissioning,
operation and maintenance, specialized devices and components and testing devices. An
auxiliary power system is a system that provides electric power for the auxiliary equipment in
power stations, substations, converter stations and telecommunications sites supporting the
power network.
From the technical point of view, an APS consists of multiple components well standardized
(e.g., station transformers, storage batteries, low-voltage switchgear, etc.). Several IEC product
standards give definitions necessary for understanding terms used for these components.
IEC 63346-1-1 allows professionals to understand and identify APS-related concepts so as to
avoid ambiguity and misunderstanding. Adopting clear and consistent terms will facilitate the
development of programs, projects and future standards.
IEC 63346-1-1 may be subject to revision to avoid mismatch. Terms and definitions have been
harmonized with the IEV, the IEC Glossary and other IEC documents as far as possible.
Definitions not included in this termino
...