Optical fibre cables - Part 1-21: Generic specification - Basic optical cable test procedures - Mechanical tests methods

Lichtwellenleiter - Teil 1-21: Fachgrundspezifikation - Grundlegende Prüfverfahren für Lichtwellenleiterkabel - Mechanische Prüfverfahren

Câbles à fibres optiques - Partie 1-21: Spécification générique - Procédures fondamentales d’essais des câbles optiques - Méthodes d’essai mécanique

Optični kabli - 1-21. del: Splošne specifikacije - Osnovni preskusni postopki za optične kable - Mehanske preskusne metode - Dopolnilo A1 (IEC 60794-1-21:2015/A1:2020)

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Publication Date
16-Apr-2020
Current Stage
6060 - Document made available
Due Date
17-Apr-2020
Completion Date
17-Apr-2020

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SLOVENSKI STANDARD
SIST EN 60794-1-21:2015/A1:2020
01-junij-2020
Optični kabli - 1-21. del: Splošne specifikacije - Osnovni preskusni postopki za
optične kable - Mehanske preskusne metode - Dopolnilo A1 (IEC 60794-1-
21:2015/A1:2020)

Optical fibre cables - Part 1-21: Generic specification - Basic optical cable test

procedures - Mechanical tests methods (IEC 60794-1-21:2015/A1:2020)

Lichtwellenleiter - Teil 1-21: Fachgrundspezifikation - Grundlegende - Prüfverfahren für

Lichtwellenleiterkabel - Mechanische Prüfverfahren (IEC 60794-1-21:2015/A1:2020)
Câbles à fibres optiques - Partie 1-21: Spécification générique - Procédures
fondamentales d’essais des câbles optiques - Méthodes d’essais mécaniques (IEC
60794-1-21:2015/A1:2020)
Ta slovenski standard je istoveten z: EN 60794-1-21:2015/A1:2020
ICS:
19.060 Mehansko preskušanje Mechanical testing
33.180.10 (Optična) vlakna in kabli Fibres and cables
SIST EN 60794-1-21:2015/A1:2020 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 60794-1-21:2015/A1:2020
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SIST EN 60794-1-21:2015/A1:2020
EUROPEAN STANDARD EN 60794-1-21:2015/A1
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2020
ICS 33.180.10
English Version
Optical fibre cables - Part 1-21: Generic specification - Basic
optical cable test procedures - Mechanical tests methods
(IEC 60794-1-21:2015/A1:2020)

Câbles à fibres optiques - Partie 1-21: Spécification Lichtwellenleiter - Teil 1-21: Fachgrundspezifikation -

générique - Procédures fondamentales d'essais des câbles Grundlegende - Prüfverfahren für Lichtwellenleiterkabel -

optiques - Méthodes d'essai mécanique Mechanische Prüfverfahren
(IEC 60794-1-21:2015/A1:2020) (IEC 60794-1-21:2015/A1:2020)

This amendment A1 modifies the European Standard EN 60794-1-21:2015; it was approved by CENELEC on 2020-04-09. CENELEC

members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this amendment the

status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC

Management Centre or to any CENELEC member.

This amendment exists in three official versions (English, French, German). A version in any other language made by translation under the

responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as

the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,

Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the

Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Ref. No. EN 60794-1-21:2015/A1:2020 E
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SIST EN 60794-1-21:2015/A1:2020
EN 60794-1-21:2015/A1:2020 (E)
European foreword

The text of document 86A/1975/FDIS, future IEC 60794-1-21/A1, prepared by SC 86A "Fibres and

cables" of IEC/TC 86 "Fibre optics" was submitted to the IEC-CENELEC parallel vote and approved by

CENELEC as EN 60794-1-21:2015/A1:2020.
The following dates are fixed:

• latest date by which the document has to be implemented at national (dop) 2021-01-09

level by publication of an identical national standard or by endorsement

• latest date by which the national standards conflicting with the (dow) 2023-04-09

document have to be withdrawn

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Endorsement notice

The text of the International Standard IEC 60794-1-21:2015/A1:2020 was approved by CENELEC as

a European Standard without any modification.

In the official version, for Bibliography, the following notes have to be added for the standards

indicated:
IEC 60794-1-23 NOTE Harmonized as EN IEC 60794-1-23
IEC 61395 NOTE Harmonized as EN 61395
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SIST EN 60794-1-21:2015/A1:2020
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
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.10 ISBN 978-2-8322-7896-3

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
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SIST EN 60794-1-21:2015/A1:2020
– 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.
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SIST EN 60794-1-21:2015/A1:2020
IEC 60794-1-21:2015/AMD1:2020 – 3 –
 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.
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SIST EN 60794-1-21:2015/A1:2020
– 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
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SIST EN 60794-1-21:2015/A1:2020
IEC 60794-1-21:2015/AMD1:2020 – 5 –
 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

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SIST EN 60794-1-21:2015/A1:2020
– 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
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SIST EN 60794-1-21:2015/A1:2020
IEC 60794-1-21:2015/AMD1:2020 – 7 –
 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.
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SIST EN 60794-1-21:2015/A1:2020
– 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.

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SIST EN 60794-1-21:2015/A1:2020
IEC 60794-1-21:2015/AMD1:2020 – 9 –
 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.
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SIST EN 60794-1-21:2015/A1:
...

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