IEC 60332-3-25:2018

IEC 60332-3-25 ®
Edition 2.0 2018-07
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
GROUP SAFETY PUBLICATION
Tests on electric and optical fibre cables under fire conditions –
Part 3-25: Test for vertical flame spread of vertically-mounted bunched wires or
cables – Category D
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IEC 60332-3-25 ®
Edition 2.0 2018-07
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
GROUP SAFETY PUBLICATION
Tests on electric and optical fibre cables under fire conditions –

Part 3-25: Test for vertical flame spread of vertically-mounted bunched wires or

cables – Category D
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 13.220.40; 29.060.20 ISBN 978-2-8322-5892-7

– 2 – IEC 60332-3-25:2018 RLV © IEC 2018
CONTENTS
FOREWORD .3
INTRODUCTION .5
1 Scope .6
2 Normative references .6
3 Terms and definitions .7
4 Test apparatus .7
4.1 General .7
4.2 Ignition source .7
5 Test procedure .7
5.1 Test sample .7
5.2 Determination of the number of test pieces .8
5.3 Mounting of the test sample .8
5.4 Flame application time .9
6 Evaluation of test results .9
7 Performance requirements .9
8 Retest procedure .9
9 Test report . 10
Annex A (normative) Guidance on cable selection for type approval testing . 11
Annex B (informative) Recommended performance requirements . 12
Bibliography . 13

Figure 1 – Touching cables mounted on the front side of the standard ladder (arrays of
cables in contact) . 10

Table A.1 – Summary of test conditions . 11

INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
TESTS ON ELECTRIC AND OPTICAL FIBRE CABLES UNDER FIRE
CONDITIONS –
Part 3-25: Test for vertical flame spread of
vertically-mounted bunched wires or cables – Category D

FOREWORD
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– 4 – IEC 60332-3-25:2018 RLV © IEC 2018
International Standard IEC 60332-3-25 has been prepared by IEC technical committee 20:
Electric cables.
This second edition cancels and replaces the first edition published in 2000 and
Amendment 1:2008. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) adjustments have been made to the title, and elsewhere, to emphasise the standard is
applicable to optical fibre cables as well as metallic conductor types;
b) details of the way in which cables are mounted on the ladder have been better defined in
order to improve repeatability and reproducibility.
It has the status of a group safety publication in accordance with IEC Guide 104.
The text of this International Standard is based on the following documents:
FDIS Report on voting
20/1802/FDIS 20/1819/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60332 series, published under the general title Tests on electric
and optical fibre cables under fire conditions, can be found on the IEC website.
Future standards in this series will carry the new general title as cited above. Titles of
existing standards in this series will be updated at the time of the next edition.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website 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.
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 publication using a
colour printer.
INTRODUCTION
IEC 60332-3-25 is part of a series of publications dealing with tests on electric and optical
fibre cables under fire conditions.
The IEC 60332-1 and IEC 60332-2 series specify methods of test for flame spread
characteristics for a single vertical insulated wire or cable. It cannot be assumed that,
because a cable or wire meets the requirements of the IEC 60332-1 and IEC 60332-2 series,
a vertical bunch of similar cables or wires will behave in a similar manner. This is because
flame spread along a vertical bunch of cables depends on a number of features, such as
a) the volume of combustible material exposed to the fire and to any flame which may be
produced by the combustion of the cables;
b) the geometrical configuration of the cables and their relationship to an enclosure;
c) the temperature at which it is possible to ignite the gases emitted from the cables;
d) the quantity of combustible gas released from the cables for a given temperature rise;
e) the volume of air passing through the cable installation;
f) the construction of the cable, for example armoured or unarmoured, multi- or single-
core.
All of the foregoing assume that the cables are able to be ignited when involved in an
external fire.
The IEC 60332-3 series gives details of a test where a number of cables are bunched
together to form various test sample installations. For easier use and differentiation of the
various test categories, the parts are designated as follows:
Part 3-10: Apparatus
Part 3-21: Category A F/R
Part 3-22: Category A
Part 3-23: Category B
Part 3-24: Category C
Part 3-25: Category D
Parts from 3-21 onwards define the various categories and the relevant procedures. The
categories are distinguished by test duration, the volume of non-metallic material of the test
sample and the method of mounting the sample for the test. In all categories, cables having
at least one conductor of cross-sectional area greater than 35 mm are tested in a spaced
configuration, whereas cables of conductor cross-sectional area of 35 mm or smaller and
optical
...