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• withdrawn,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 withdrawal of cable elements, midspan, for external connection, as in MDU
retractable cable.
NOTE The optical elements can be a fibre, a cord, a ribbon, a micro-module, or other, as appropriate.
34.2 Apparatus
An apparatus shall be constructed to test a cable according to either procedure 1 or procedure
2 described in 34.4.2 and 34.4.3 respectively. The apparatus shall conform to the conceptual
description of the test below, using the variations described in procedures 1 and 2.
The concept of the test is as follows (refer to Figure 37).
– A part of the cable sheath is removed (window 2) to have access to the optical elements.
– Depending on need, one or several elements are cut in window 2.
– A second window (window 1) is made on the cable.
– Elements cut in window 2 can be removed from window 1.

Figure 37 – Concept of straight midspan access

 IEC 2020
The apparatus shall consist of the following.
– Positions for opening windows 1 and 2 (Figure 37), with space between. The space shall be
6 m, unless otherwise specified.
– Fixturing between the window positions to route the cable as specified:
• straight, per Figure 37, if required;
• two controlled bends, per Figure 38 a) and 38 b); and
• one S-bend, per Figure 39.
– Appropriate clamping fixtures to secure the cable for the test without compressing the cable
or imparting increased attenuation.
34.3 Sample
A single cable sample, 50 m in length, shall be used. Alternatively, two samples from like cables,
each 20 m, may be used. Other lengths may be used, as specified.
34.4 Procedure
34.4.1 General
The manufacturer shall propose methods and tools to open windows of 80 mm length in the
cable without risk to damage elements or fibres. The manufacturer shall propose methods to
avoid risk of tight bends (below the minimum bend radius) or kinking of elements during the
removal from the cable.
Remove a length of one of two adjacent elements (microbundle or buffer) using one or both of
the two procedures below, as specified.
The attenuation of cable elements not removed shall be monitored during the test. The number
of fibres monitored shall be specified by the detail specification.
34.4.2 Procedure 1
– A section of a cable sample, approximately 15 m from an end, shall be laid according to the
configurations described in Figure 37, having two bends, preferentially in a vertical position.
The size and locations of the bends shall meet the following criteria:
• ≥ 4 core lay length twists between the bends (Figure 38 a));
• 2 bends produced using the criteria below, per Figure 38 b), and separated by 3 m
(Figure 38 a)):
i) 3 mandrels: 30 mm in diameter;
ii) depth: 100 mm;
iii) length: 200 mm.
– 8 – IEC 60794-1-21:2015/AMD1:2020
 IEC 2020
a) Location of bends
Dimensions in millimetres
b) Details of bend
Figure 38 – Straight midspan access – Procedure 1
– Block elements of the cable at each end of the cable, beyond the window locations, by
folding them or coiling the cable.
– Monitor the attenuation of the non-removed elements, as specified.
– Open two windows, separated by 6 m, according to the manufacturer’s method, to provide
access to elements. Verify the integrity of the elements after this operation.
– Cut two adjacent elements at window 2.
– From window 1, remove one of the two elements, according to the manufacturer’s
procedure.
• Measure the tensile stress needed with a dynamometer, if required.
• Measure any displacement of the other cut element.
34.4.3 Procedure 2
At a position in the sample approximately 15 m from the site of procedure 1, make two windows,
separated by 6 m, as in Procedure 1. Block the fibres at the ends, as in procedure 1.
Between these two windows, make two right angles, bent at the minimum bend radius of the
cable under test. The two bends shall be immediately adjacent to each other. See Figure 39.

 IEC 2020
Figure 39 – Straight midspan access – Procedure 2
Perform procedure 2 in the same manner as the procedure 1. The key functional parts of the
procedure are the following.
– Cut two adjoining elements in window 1.
– Remove one element from window 2.
• Measure the tensile stress needed to remove it, if required.
• Measure the displacement of the other cut element.
34.4.4 Overview
Accomplish procedures 1 and 2 successively. At the end of each procedure, visually examine
the removed and non-removed elements and any fibres within to assess any abrasion of fibre
and elements.
34.5 Requirements
Acceptance criteria in the detail specification may include
– no abrasion or perforation of the elements or fibres,
– no broken fibres in either the removed or non-removed elements,
– maximum allowed attenuation increase,
– maximum allowed sliding distance of the non-removed element, and
– maximum allowed tensile stress.
34.6 Details to be specified
The following shall be specified in the detail specification:
– cable type to be tested;
– if the tensile stress to remove the elements is to be measured;
– the maximum tensile stress to remove an element, if required.
35 Method E30: Coefficient of friction between cables
35.1 Object
The object of this test is to ensure that the coefficient of friction of the sheathing material of a
specified cable against another specified cable is less than the value specified. Coefficient of
friction between two cables is an important parameter for installation of a cable in a duct or tray
having previously installed cable.

– 10 – IEC 60794-1-21:2015/AMD1:2020
 IEC 2020
35.2 Sample
Two cables, which may be of the same type and size, or different, as specified, are selected.
The first cable shall be of sufficient length to make 2, or more (as specified), turns on the test
sheave. The second cable shall be of sufficient length of make 1/2 turn about the test sheave
holding the first cable, plus length sufficient for pulling and for attaching the pulling apparatus
and the snubbing force apparatus on the ends.
35.3 Apparatus
The apparatus, illustrated in Figure 40, shall consist of the following.
– A sheave: the sheave root diameter, D , shall be 20 to 25 times the second cable diameter
m
(but not less than the minimum bend diameter of that cable), with a circular groove formed
by a radius, R, of a minimum of 5 times the second cable diameter.
For cables that are not round, use the minimum dimension.
– A weight for attachment to one end of the second cable, sufficient to apply a snubbing force
tension so that the second cable contours the sheave: 1 N is generally sufficient, or it may
be as specified.
– An apparatus to apply a pulling force to one end of the second cable.
– A tensile measuring apparatus attached to the sheave.

 IEC 2020
Key
F snubbing force, generally a weight, sufficient to make cable contour the sheave
s
F pulling force, sufficient to move the cable, but not specified or measured
p
F measured reaction force on the mandrel
D sheave root diameter, 20 to 25 × d, or as specified
m
R sheave face radius, min. 5 × d, or as specified
Figure 40 – Coefficient of friction test apparatus (drum test)
35.4 Procedure
– Wind the first cable sample on the sheave using 2, or more (as specified), adjacent turns.
Fix this coil in place.
– Wind the second cable sample in a half-turn on top of the coil. Alternatively, for thin cords,
wind the second cable sample in a quarter-turn on top of the coil.
– Apply a snubbing force (weight in 35.3), F , to one end of the second cable and a tensile
S
pulling force, F , to the other end of that sample, so as to move it on to the coil at a constant
P
speed of 3 mm/min. The force F is not measured.
P
– Using the tensile measuring apparatus, measure the reaction force, F, on the sheave while
the second cable is moving. The value of F used in Equation (17) and Equation (18) shall
be the average of the peak forces observed during the test.
– Calculate the coefficient of friction using Equation (17) for the half-turn case or Equation (18)
for the quarter-turn case.
– 12 – IEC 60794-1-21:2015/AMD1:2020
 IEC 2020

1 FF−
S
μ= ln (17)

π F
S


1 FF−
S
(18)
μ= ln

π/ 2 F
S

35.5 Requirement
The calculated coefficient of friction shall be less that the value specified.
35.6 Details to be specified
The detail specification shall include the following:
– cables to be tested;
– turns on the sheave, if different from 2;
– mandrel root diameter (D ), if different than 20 × d;
m
– sheave face radius, if different from 5 × d;
– snubbing force, F , if different from the default
S
36 Method E31: Microduct inner clearance test: under consideration
37 Method E32: Creep behaviour tension test (for ADSS)
37.1 Object
This test method applies to all-dielectric self-supported (ADSS) optical fibre cables. The object
is to predict the increase of cable length due to permanent, cyclic load throughout the
operational life of cable. It provides means for engineering data useful to predict the long-term
cable sag of dielectric cables installed on overhead power lines. The test method evaluates
cable creep behaviour while requiring a reduced period of time for execution. There is no optical
requirement, nor pass fail criteria for this test.
NOTE 1 Results obtained by alternative methods (e.g. IEC 61395), as agreed between customer and supplier, can
also be used.
Instead of applying a constant load for an extended period of time, it simulates the variable
loads an ADSS cable is expected to experience during its operational lifetime. Low – high – low
tension cycles are applied to the sample and the cable strain values are registered for each
condition. As the number of applied load cycles increases, the cable strain values will show a
trend value that can be related to long-term strain or creep prediction.
NOTE 2 This test method was developed by WG 3 of SC 86A, considering for low load level the value recommended
by manufacturer as installation (sagging) limit (MIT) and for high load the specified maximal tension (MAT). A round
robin test showed that, for low-tension cables, the resultant strain was not detectable in some laboratories, due to
high incertitude in measurements; additional round-robin tests with 50 % increase in load values showed adequate
results. This procedure is focused on mechanical behaviour, with no optical requirement; during evaluation, the
declared maximal tension recommended for the cable operation can be exceeded in order to improve readings noting
that high load level is not close to the cable breaking load limit.
37.2 Sample
The sample length under tension shall be ≥ 15 m unless otherwise defined in the relevant
specification. Shorter lengths will adversely affect the accuracy of the measurement.
Total sample length will be longer than the length under tension to allow for clamping and
connection to test equipment.
 IEC 2020
37.3 Apparatus
The apparatus, illustrated in Figure 41, consists of the following.
a) A tensile strength measuring apparatus which is able to axially accommodate the cable
length to be tested.
b) A load cell with a maximum error of ±2 % of its maximum range.
c) A clamping device to secure all cable components at the ends of the length under test. Care
should be taken that the specific method of securing the cable components does not affect
the results. Pre-formed dead-ends used in field operation are considered adequate for fixing
the ends of the cable.
The attaching points on the equipment shall be rigid and of enough mechanical resistance
to not be deformed while load cycles application.
The use of length extensions from the clamps on cable to the fixing points in the equipment
shall not be used as this would result in negative influence on the cable strain readings.
d) A mechanical or electrical means for measuring the cable load and elongation on a
controlled length of cable. The cable elongation measurements should be taken with
minimum accuracy of 0,10 mm.
e) A rod of 10,00 m length to delimit the control length of the sample under test. This rod will
be attached parallel to the sample under test to be used as the base length to calculate the
cable elongation. A dielectric rigid material is recommended in order to minimize errors on
the strain measurement due to temperature variations.
NOTE The term "strain" is used to indicate cable elongation.

Figure 41 – Tensile cycling test apparatus
37.4 Procedure
37.4.1 General procedure requirements
a) The test sample should be attached to the test equipment. A rigid rod should be clamped to
the sample under test to define the control length; one end of the rod should be fixed to the
cable and the other end should be loose to allow free movement.
b) Load the cable and secure it at both ends of the tensile rig. A method of securing the cable
shall be used, which uniformly locks the cable so that all components of the cable, including
fibres, are restricted in their movement to prevent the fibres from slipping.
c) Apply initial load to straighten the sample. Typically a 20 kg. load is sufficient. If necessary,
use attaching means along the 10,00 m control length, in order to avoid a catenary effect
and keep the sample straight under this tension. See Figure 42.
d) The tension shall be continuously increased to the required values indicated in the steps
detailed in 37.4.2.
e) The strain readings shall be taken at the end of the time periods stated in 37.4.2.
f) When changing the tension level on cable, the rate change shall be continuous and
homogenous. The target tension shall be reached maximum within a 3 min period of time.
g) If interruptions greater than 30 min occur while applying the sequence of tension cycles, the
sample should remain loaded at MAT.

– 14 – IEC 60794-1-21:2015/AMD1:2020
 IEC 2020
NOTE Attenuation reading can be made while the load is between MIT and MAT values in order to verify that the
cable meets tension specification, although this is not correlated to creep determination.

Figure 42 – Control cable length arrangement
37.4.2 Procedure steps
1) Apply the maximum installation tension (MIT) specified by the manufacturer and, without
any further tension adjustment in the apparatus, maintain for 60 min (i.e. the applied load
does not need to be maintained during this time).
2) Increase load to the maximum allowable tension (MAT) and, without any further tension
adjustment in the apparatus, maintain for 20 min.
3) Return the sample to MIT and, without any further tension adjustment in the apparatus,
maintain for 20 min.
4) Put marks on the test sample to delimit the control cable length (L) and define the cable
zero strain baseline. Register the load level for the end of this cycle.
5) Increase the load to 1,5 times MAT and hold for 20 min without any further tension
adjustment in the apparatus. The load at the end of this cycle is defined as the high tension
level. With creep involved, the load at the end of the 20 min is expected to be lower than at
the beginning of the cycle.
6) Record the tension load and control cable length strain (Ai) at high tension level for this
cycle compared to baseline from step 4).
7) Lower the sample to MIT and maintain for 15 min without any adjustment, in order to
eradicate residual tension. Raise the load to 1,5 times MIT and, without additional tension
adjustments in the apparatus, hold for 20 min. The load at the end of this cycle is the low
load. The load of 1,5 times MIT is to be applied during the first cycle only. In subsequent
cycles, the load applied shall be the low load measured at the end of the previous cycle (Γ),
i.e. in cycle n, the applied load shall be Γ . See Figure 44.
n–1
8) Record the load level and the control cable length strain (Bi) at low tension level for this
cycle compared to the baseline from step 4).
9) Repeat steps 5) to 8) until 50 tension cycles have been performed and cable length and
strain readings are registered. See Figure 43 for guidance on this procedure.
NOTE Steps 1) to 3) represent the initial bedding-in of the cable elements, step 4) is the recording of baseline
measurements and steps 5) to 9) are the load cycles.

 IEC 2020
Key
th
cycle at high load level
Ai measured cable strain for i
th
Bi measured cable strain for i cycle at low load level
reference mark to follow cable strain
Figure 43 – Delimiting zero strain baseline for high load level and low load level

Figure 44 – Load applied on cable sample
37.5 Calculations
a) Creep is expressed as
(∆L )/L
n
where
(∆LA)i is Ai for high load level strain in cycle i;
(∆LB)i is Bi for low load level strain in cycle i.
b) After the last load has been applied in cycle 50, measure the final control length strain, ∆L
for high and low load values.
c) Additionally, a graph with the measured cable strain at high load and cable strain at low
load can be constructed. For this purpose, discard the values of the first cycle and determine
a fitted curve with all other data in order to obtain the tendency of strain as a function of
load cycles. See Figure 45.
– 16 – IEC 60794-1-21:2015/AMD1:2020
 IEC 2020
Dotted lines define the (∆LA) and (∆LB) final values.
Figure 45 – Strain of ADSS cable at high load as function of load cycles
37.6 Details to be specified
The relevant specification shall include the following:
– length under tension if different from this method;
– MAT (maximum allowed tension) load as specified by the manufacturer;
– MIT (maximum installation tension) load as specified by the manufacturer.
37.7 Details to be reported
– Table for load and strain measured in 37.4.2.
– Final creep level, in percentage, at the end of 50 load cycles for the high load level and for
the low load level.
37.8 Additional information
• Values for load and strain in the first cycle. Designated as initial deformation.
• The graphs of load variation as a function of cycles, both for high load level and low load
level, as described in 37.4.2. See Figure 44.
• The graphs of cable strain as a function of load cycles, both for high load level and low
tension level, as described in 37.4.2. See Figures 45.
• The fitted equation of the cable strain.
• Description of the anchoring devices used; accuracy of load cell/dynamometer.
• Rate of load increase and test temperature, if different from that indicated for standard test
conditions.
 IEC 2020
38 Method E33: Multiple cable coiling and uncoiling performance
38.1 Object
The purpose of this test is to demonstrate the ability of an optical fibre cable to withstand
multiple coiling and uncoiling on a specified cable reel. This test is primarily intended to evaluate
the performance of cables for mobile rapid/multiple deployment.
The intention of the test is to examine the attenuation change and the physical damage of the
cable as a function of the multiple coiling and uncoiling which may occur during operation. This
method is intended to be non-destructive.
38.2 Sample
The sample length coiled on the reel shall be specified in the relevant specification in
accordance with the specified number of coils per layer, the specified test cable reel core
diameter and the specified number of cycles. Total sample length shall be longer than the coiled
length on the test cable reel to allow for connection to test equipment and, if necessary, to have
sufficient length to permit optical measurements. Fibres may be spliced at the cable ends.
If the cable is used as a terminated cable assembly, the test sample shall be terminated at both
ends or all cable elements shall be fixed together in appropriate manner prior to testing.
38.3 Apparatus
The apparatus consists of the following.
a) Optical test equipment needed to measure the changes in optical performance as required
in the relevant specification, and as described in IEC 60793-1-46.
b) Test cable reel on which the cable can be coiled and uncoiled over the specified cylindrical
core diameter. The core diameter of the test cable reel shall be in accordance with the
minimum specified bend diameter of the cable.
c) A clamping device to secure all cable elements at the ends of the length under test: care
should be taken that the specific method of capturing the cable elements does not affect the
results.
38.4 Procedure
a) Unless otherwise specified, the conditions for testing shall be in accordance with the
standard atmospheric conditions, as defined in IEC 60794-1-2.
b) A representative number of fibres for optical measurement shall be agreed between the
customer and supplier.
c) Uncoil the required cable sample length from the transport cable reel and connect the
specified fibres of the other cable end to the measurement apparatus. All uncoiling and
coiling operations shall be performed without inducing torsion into the sample, for example
do not pull the cable over the flange of the reel.
d) Make initial measurement of the uncoiled cable sample length.
e) Coil the specified cable length tightly on the test cable reel at a uniform rate, so that cable
coils are adjacent to each other but do not squeeze themselves laterally. Sufficient tension
shall be applied to ensure that the sample contours the cylindrical core of the reel and that
the sample coils do not slip laterally.
f) Make measurement of the coiled sample. The change of attenuation shall be recorded.
g) Uncoil the sample from the test cable reel and lay it straight on the floor. Alternatively, the
cable can be coiled back on the manufacturing reel. Measure and record the change of
attenuation.
h) The cycle consists of the coiling and uncoiling of the sample.
i) Repeat the cycle according to the specified number of cycles.

– 18 – IEC 60794-1-21:2015/AMD1:2020
 IEC 2020
38.5 Requirements
The acceptance criteria for the test shall be stated in the relevant specification.
Typical failure modes include physical damage to the cable, residual degradation of optical
performance beyond the specified level and/or loss of continuity.
38.6 Details to be specified
The relevant specification shall include the following information:
a) test reel core diameter;
b) sample length to be coiled on test reel;
c) number of coils per layer;
d) speed and tensile force for the uncoiling and coiling operations;
e) number of cycles;
f) maximum allowable attenuation change:
– during the test;
– after the test (uncoiled sample).
39 Method E34: Coefficient of dynamic friction between cables
39.1 Object
The object of this test is to evaluate the coefficient of dynamic friction of the sheathing material
of the pulled cable against the other same type cable.
39.2 Sample
The sample of a cable shall be of a sufficient length to make both the movable (1 piece) and
the fixed (4 pieces) specimens for the test. A first specimen shall be of a length of 300 mm or
longer as a movable cable piece. Four other specimens used as fixed cable pieces shall be of
a length of 150 mm. See Figure 46.

Figure 46 – Coefficient of friction test apparatus (flat plate test)

 IEC 2020
39.3 Apparatus
The apparatus shall allow a specimen of cable to be moved between fixed specimens of the
same cable. The movable and fixed specimens shall be set between two flat plates, and a load
shall be added on upper side of the plates. The movable specimen and a load cell shall be
connected with a wire via a puller, which is used to pull a movable sample.
The apparatus is shown in Figure 46.
39.4 Procedure
The cable specimens with a length of 150 mm shall be fixed on the two plates, and then a
movable cable specimen shall be mounted between the fixed cable samples.
A load shall be added to the cable specimens by loading the upper plate. A value of the added
load, F shall be 19,6 N.
The load cell shall pull the wire which connects with the movable cable specimen. The velocity
to pull the wire shall be 500 mm/min.
The pulling force, F, shall be measured and then the coefficient of friction shall be calculated
using Equation (19).
F
(19)
μ=
F
39.5 Details to be specified
The detail specification shall include the following:
a) velocity to pull the wire; if other than the velocity of 500 mm/min;
b) load added to cable specimens; if other than the load of 19,6 N;
c) maximum force to pull the wire, if required;
d) maximum coefficient of friction as calculated using Equation (19), if required.

– 20 – IEC 60794-1-21:2015/AMD1:2020
 IEC 2020
Bibliography
Add the following new references:
[2] IEC 60794-1-23, Optical fibre cables – Part 1-23: Generic specification – Basic optical
cable test procedures – Cable element test methods
[3] IEC 61395, Overhead electrical conductors – Creep test procedures for stranded
conductors
_____________
– 22 – IEC 60794-1-21:2015/AMD1:2020
 IEC 2020
AVANT-PROPOS
Le présent amendement a été établi par le sous-comité SC 86A: Fibres et câbles, du comité
d'études 86 de l'IEC: Fibres optiques.
Le texte de cet amendement est issu des documents suivants:
FDIS Rapport de vote
86A/1975/FDIS 86A/1990/RVD
Le rapport de vote indiqué dans le tableau ci-dessus donne toute information sur le vote ayant
abouti à l'approbation de cet amendement.
Le comité a décidé que les contenus de cet amendement et de la publication de base ne seront
pas modifiés avant la date de stabilité indiquée sur le site web de l'IEC sous
"http://webstore.iec.ch" dans les données relatives à la publication recherchée. A cette date, la
publication sera
• reconduite,
• supprimée,
• remplacée par une édition révisée, ou
• amendée.
IMPORTANT – Le logo "colour inside" qui se trouve sur la page de couverture de cette
publication indique qu'elle contient des couleurs qui sont considérées comme utiles à
une bonne compréhension de son contenu. Les utilisateurs devraient, par conséquent,
imprimer cette publication en utilisant une imprimante couleur.

_____________
INTRODUCTION à l’Amendement
Le présent amendement ajoute de nouvelles méthodes d’essai et révise les méthodes d’essai
existantes, en un temps opportun, préalablement à la prochaine révision complète de
l’IEC 60794-1-21:2015.
La numérotation de la série E applicable aux méthodes d’essai, aux numéros de paragraphe,
aux figures et aux équations de la section technique est alignée avec l’IEC 60794-1-21:2015.
Dans le cadre de la rationalisation actuelle de l’ensemble des spécifications des méthodes
d’essai, plusieurs essais de l’IEC 60794-1-21 se sont avérés mieux alignés avec les autres
essais de l’ensemble et ont été déplacés. A cette fin, le texte proposé pour affecter ces
déplacements a été inséré dans le présent document.
L'Article 7 a été redésigné comme une méthode d’essai d’élément de câble. Il a été déplacé
dans l’IEC 60794-1-23 Ed2 et s’est vu attribuer le numéro de méthode d’essai G10A.
L'Article 8 a été redésigné comme une méthode d’essai d’élément de câble. Il a été déplacé
dans l’IEC 60794-1-23 Ed2 et s’est vu attribuer le numéro de méthode d’essai G10B.

 IEC 2020
L'Article 18 a été redésigné comme une méthode d’essai d’environnement. Il a été déplacé
dans l’IEC 60794-1-22 Ed2 et s’est vu attribuer le numéro de méthode d’essai F16.
L'Article 19 a été redésigné comme une méthode d’essai d’élément de câble. Il a été déplacé
dans l’IEC 60794-1-23 Ed2 et s’est vu attribuer le numéro de méthode d’essai G9.
1 Domaine d’application et objet
Remplacer le dernier alinéa existant par le nouvel alinéa suivant:
Voir l’IEC 60794-1-2 pour les exigences générales et les définitions, et un guide de référence
complet pour tous les types de méthodes d’essai.
7 Méthode E5A: Stabilité de la force de dénudage des fibres optiques câblées
Supprimer la totalité de l'article, y compris son titre.
8 Méthode E5B: Dénudabilité des rubans de fibres optiques
Supprimer la totalité de l'article, y compris son titre.
18 Méthode E14: Ecoulement (égouttement) des matériaux de remplissage
Supprimer la totalité de l'article, y compris son titre.
19 Méthode E15: Dégorgement et évaporation
Supprimer la totalité de l'article, y compris son titre.
32 Méthode E27: Essai d’installation simulée en intérieur
Remplacer le texte existant par le nouveau texte suivant:
32.1 Objet
Cet essai est conçu pour simuler l’installation d’un câble intérieur à des emplacements où des
angles étroits, des points d’ancrage et un stockage de câble peuvent être présents. Cet essai,
nettement plus sévère que les pratiques d’installation traditionnelles, a pour but de démontrer
le niveau de solidité du câble soumis à essai.
NOTE Cet essai
...