IEC TR 62368-2:2015

IEC TR 62368-2 ®
Edition 2.0 2015-02
TECHNICAL
REPORT
colour
inside
Audio/video, information and communication technology equipment –
Part 2: Explanatory information related to IEC 62368-1

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.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé Fax: +41 22 919 03 00

CH-1211 Geneva 20 info@iec.ch
Switzerland www.iec.ch
About the IEC
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
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing more than 30 000 terms and
Technical Specifications, Technical Reports and other definitions in English and French, with equivalent terms in 15
documents. Available for PC, Mac OS, Android Tablets and additional languages. Also known as the International
iPad. Electrotechnical Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a More than 60 000 electrotechnical terminology entries in
variety of criteria (reference number, text, technical English and French extracted from the Terms and Definitions
committee,…). It also gives information on projects, replaced clause of IEC publications issued since 2002. Some entries
and withdrawn publications. have been collected from earlier publications of IEC TC 37,

77, 86 and CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: csc@iec.ch.
IEC TR 62368-2 ®
Edition 2.0 2015-02
TECHNICAL
REPORT
colour
inside
Audio/video, information and communication technology equipment –

Part 2: Explanatory information related to IEC 62368-1

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 35.020; 33.160.01 ISBN 978-2-8322-2268-3

– 2 – IEC TR 62368-2:2015 © IEC 2015

INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
AUDIO/VIDEO, INFORMATION AND
COMMUNICATION TECHNOLOGY EQUIPMENT –

Part 2: Explanatory information related to IEC 62368-1:2014

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)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of

patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC 62368-2, which is a technical report, has been prepared by subcommittee TC 108: Safety
of electronic equipment within the field of audio/video, information technology and
communication technology.
This second edition cancels and replaces the first edition published in 2011. This edition
constitutes a technical revision.
This second edition updates the first edition of IEC 62368-2 published in 2011 to take into
account changes made to IEC 62368-1:2010 as identified in the Foreword of IEC 62368-
1:2014.
This Technical Report is informative only. In case of a conflict between IEC 62368-1 and

IEC TR 62368-2, the requirements in IEC 62368-1 prevail over this Technical Report.

The text of this technical report is based on the following documents:

Enquiry draft Report on voting

108/540/DTR 108/553/RVC
Full information on the voting for the approval of this technical report can be found in the

report on voting indicated in the above table.

In this standard, the following print types are used:
– notes/explanatory matter: in smaller roman type;
– tables and figures that are included in the rationale have linked fields (shaded in grey if
“field shading” is active).
In this standard, "HBSDT" stands for Hazard Based Standard Development Team, which is
the Working Group of TC 108 responsible for the development and maintenance of IEC
62368-1.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 62368 series can be found, under the general title Audio/video,
information and communication technology equipment, on the IEC website.
In this document, only those subclauses considered to need further background reference
information or explanation of their content to benefit the reader are included. Therefore, not
all numbered subclauses are cited. Unless otherwise noted, all references are to clauses,
subclauses, annexes, figures or tables are located in IEC 62368-1:2014.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 4 – IEC TR 62368-2:2015 © IEC 2015

AUDIO/VIDEO, INFORMATION AND
COMMUNICATION TECHNOLOGY EQUIPMENT –

Part 2: Explanatory information related to IEC 62368-1:2014

Clause 0 Principles of this product safety standard

Clause 0 is informational and provides a rationale for the normative clauses of

the standard.
0.5.1 General
ISO IEC Guide 51:2014, 6.3.5 states:
“When reducing risks the order of priority shall be as follows:
a) inherently safe design;
b) guards and protective devices;
c) information for end users.
Inherently safe design measures are the first and most important step in the
risk reduction process. This is because protective measures inherent to the
characteristics of the product or system are likely to remain effective,
whereas experience has shown that even well-designed guards and
protective devices can fail or be violated and information for use might not
be followed.
Guards and protective devices shall be used whenever an inherently safe
design measure does not reasonably make it possible either to remove
hazards or to sufficiently reduce risks. Complementary protective measures
involving additional equipment (for example, emergency stop equipment)
might have to be implemented.
The end user has a role to play in the risk reduction procedure by complying
with the information provided by the designer/supplier. However, information
for use shall not be a substitute for the correct application of inherently safe
design measures, guards or complementary protective measures.”
In general, this principle is used in IEC 62368-1. The table below shows a
comparison between the hierarchy required in ISO IEC Guide 51 and the
hierarchy used in IEC 62368-1:2014:

ISO IEC Guide 51 IEC 62368-1
a) inherently safe design 1. inherently safe design by limiting all energy
hazards to class 1
b) guards and protective devices 2. equipment safeguards
3. installation safeguards
c) information for end users 4. behavioral safeguards
5. instructional safeguards
0.5.7 Equipment safeguards during skilled person service conditions
Purpose: To explain the intent of requirements for providing safeguards against
involuntary reaction.
Rationale: By definition, a skilled person has the education and experience to identify all
class 3 energy sources to which he may be exposed. However, while servicing
one class 3 energy source in one location, a skilled person may be exposed to
another class 3 energy source in a different location.

In such a situation, either of two events is possible. First, something may cause

an involuntary reaction of the skilled person with the consequences of contact

with the class 3 energy source in the different location. Second, the space in

which the skilled person is located may be small and cramped, and inadvertent

contact with a class 3 energy source in the different location may be likely.

In such situations, this standard may require an equipment safeguard solely for

the protection of a skilled person while performing servicing activity.

___________
Clause 1 Scope
Purpose: To identify the purpose and applicability of this standard and the exclusions
from the scope.
Rationale: The scope excludes requirements for functional safety. Functional safety is
addressed in IEC 61508-1. Because the scope includes computers that may
control safety systems, functional safety requirements would necessarily
include requirements for computer processes and software.
___________
Clause 2 Normative references
The list of normative references is a list of all documents that have a normative
reference to it in the body of the standard. As such, referenced documents are
indispensable for the application of this standard. For dated references, only
the edition cited applies. For undated references, the latest edition of the
referenced document (including any amendments) applies.
Recently, there were some issues with test houses that wanted to use the
latest edition as soon as it was published. As this creates serious problems for
manufacturers, since they have no chance to prepare, it was felt that a
reasonable transition period should be taken into account. This is in line with
earlier decisions taken by the SMB that allow transition periods to be
mentioned in the foreword of the standards. Therefore TC 108 decided to
indicate this in the introduction of the
...