IEC 60794-1-21:2015/AMD1:2020

IEC 60794-1-21 ®
Edition 1.0 2020-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
A MENDMENT 1
AM ENDEMENT 1
Optical fibre cables –
Part 1-21: Generic specification – Basic optical cable test procedures –
Mechanical test methods
Câbles à fibres optiques –
Partie 1-21: Spécification générique – Procédures fondamentales d'essais
des câbles optiques – Méthodes d'essai mécanique

IEC 60794-1-21:2015-03/AMD1:2020-03(en-fr)

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IEC 60794-1-21 ®
Edition 1.0 2020-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
A MENDMENT 1
AM ENDEMENT 1
Optical fibre cables –
Part 1-21: Generic specification – Basic optical cable test procedures –

Mechanical test methods
Câbles à fibres optiques –
Partie 1-21: Spécification générique – Procédures fondamentales d'essais

des câbles optiques – Méthodes d'essai mécanique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.10 ISBN 978-2-8322-7896-3

– 2 – IEC 60794-1-21:2015/AMD1:2020
 IEC 2020
FOREWORD
This amendment has been prepared by subcommittee SC 86A: Fibre optics, of IEC technical
committee TC 86: Fibres and cables.
The text of this amendment is based on the following documents:
FDIS Report on voting
86A/1975/FDIS 86A/1990/RVD
Full information on the voting for the approval of this amendment can be found in the report on
voting indicated in the above table.
The committee has decided that the contents of this amendment and the base 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• withdrawn,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 document using a colour printer.

_____________
INTRODUCTION to Amendment
This Amendment adds new test methods and revises existing ones in a timely fashion until the
next full revision of IEC 60794-1-21:2015.
Both the E-series numbering of the test methods, clause numbers, figures and equations of the
technical section are aligned with IEC 60794-1-21:2015.
As part of the ongoing rationalization of the test methods specification set, several tests of
IEC 60794-1-21 were determined to be more properly aligned with others of the set and have
been moved. To that end, the proposed text to affect these moves has been inserted in this
document.
Clause 7 has been redesignated as a cable element test method. It has been moved to
IEC 60794-1-23 Ed2 and given the test method number G10A.
Clause 8 has been redesignated as a cable element test method. It has been moved to
IEC 60794-1-23 Ed2 and given the test method number G10B.

 IEC 2020
Clause 18 has been redesignated as an environmental test method. It has been moved to
IEC 60794-1-22 Ed2 and given the test method number F16.
Clause 19 has been redesignated as a cable element test method. It has been moved to
IEC 60794-1-23 Ed2 and given the test method number G9.
1 Scope and object
Replace the existing last paragraph by the following new paragraph:
See IEC 60794-1-2 for general requirements and definitions and for a complete reference guide
to test methods of all types.
7 Method E5A: Stripping force stability of cabled optical fibres
Delete the entire clause, including its title.
8 Method E5B: Strippability of optical fibre ribbons
Delete the entire clause, including its title.
18 Method E14: Compound flow (drip)
Delete the entire clause, including its title.
19 Method E15: Bleeding and evaporation
Delete the entire clause, including its title.
32 Method E27: Indoor simulated installation test
Replace the existing text by the following new text:
32.1 Object
This test is designed to simulate an installation of an indoor cable where tight corners,
attachment points and cable storage may occur. This test is intended to demonstrate a level of
robustness of the cable tested which is more severe than traditional installation practices.
NOTE This test is primarily intended to evaluate the performance of cables containing bending loss insensitive
fibres. Indoor cables containing other fibre types are not assumed to fulfil the requirements associated with this test.
32.2 Sample
The cable sample shall be of sufficient length to accommodate the route necessary to
accomplish the steps of the procedure defined in 32.4 and to allow the specified optical testing.
A minimum length of 100 m is recommended.

– 4 – IEC 60794-1-21:2015/AMD1:2020
 IEC 2020
32.3 Apparatus
The apparatus shall be made of a material as specified in the detail specification. In general,
the apparatus is a building wall "stud" or other substrate of sufficient length to accommodate
the required wraps and attachment points. The test fixtures (see Figures 34 and 36) are
intended to simulate installation around a door or a window as well as cable that skirts around
obstacles using staples or other attachment methods as specified.

Key
Test sequence number
1 multiple corner bends
2 corner bend, 2 kg load
3 corner bend, residual load
4 mandrel wrap
5 attachments, serial
M optical measurement
F.D. cable fixing device, as in method E28, for example
r 1 mm corner radius
D 10 mm mandrel diameter
F 2 kg load
F residual load for cable specified
The test sequences correspond to the numbered items of 32.4.
Figure 34 – Indoor installation simulation apparatus

 IEC 2020
Figure 36 – Stapling and bending test fixture
The apparatus of Figure 36 may be used for the multiple corner bends section (1) and the serial
attachment section (5) of Figure 34 with results that are comparable.
NOTE The material and attachment methods are significantly affected by local building practices. Many areas use
a wooden stud; steel, composite materials, etc. are also common.
32.4 Procedure
A continuous length of cable shall progress through each of the following conditions. See Figure
34.
1) Fourteen or fifteen 90° corner bends (1 mm radius), as appropriate for the fixture, with
minimal manual tension, sufficient to wrap the cable around the fixture.
Use of a wood device for corner bends can result in indentation in the device that could
produce incorrect bending and test results. The use of metallic materials for the device or
for the corners is recommended.
NOTE The specified bend radius is that of the apparatus corner. The cable is not presumed to assume the
1 mm radius bend. The structure of a cable under load, as specified, will result in a cable bend radius that is
characteristic of the cable structure, thus determining whether said cable can operate when bent around the
corners and mandrel of the specified apparatus.
2) One 90° corner bend (1 mm radius) with a 2 kg load.
3) One 90° corner bend (1 mm radius) with rated residual load.
4) Two 10 mm diameter mandrel wraps.
5) Thirty attachment points, as specified in the detail specification.
Many fastening methods for cables can be considered, including appropriate staples,
adhesives, and cable ties. Methods shall be compatible with the substrate used and local
practices.
In the case of stapling, only crowned (round) staples of dimensions compatible with the size
of the cable are allowed. Staple according to the state of the art. Follow the procedures
recommended by the manufacturer.
6) Test the cable for a period of time sufficient for any attenuation change to become stable.
32.5 Requirements
The acceptance criteria for the test shall be stated in the detail specification. Typical failure
modes include damage to the cable or cable elements, residual degradation of optical
performance beyond the specified level, or loss of continuity.
It is recommended that the attenuation due to the stapling should not be greater than

– 6 – IEC 60794-1-21:2015/AMD1:2020
 IEC 2020
– 0,20 dB at 1 550 nm for single-mode fibre, or
– 0,40 dB at 1 300 nm for multimode fibre.
32.6 Details to be specified
The following shall be specified in the detail specification:
– cable type to be tested;
– type of substrate;
– number of 90° corner bends under minimal manual tension, if different from 32.4;
– number of 90° corner bends under load, if different from 32.4;
– the radius of the sharp corner, if different from 32.4;
– type of attachment; method and distance separating the attachment points, if required;
– tension for 32.4, 2), if different from 32.4;
– cable rated residual load;
– test temperature;
– acceptance criteria (see 32.5).
Add, after the existing Clause 33, the following new clauses:
34 Method E29: Straight midspan access to optical elements
34.1 Object
This test is to evaluate if a core optical element can be effectively removed from a cable by
midspan access. A substantially straight cable being tested is subjected to two types of
controlled minor bends for the test. This test is intended to evaluate a cable type which is
designed for easy with
...