Bsi bs en 50396 2005 + a1 2011

A1 1998 2001 Insulating and sheathing materials of electric and optical cables - Common test methods - Part 2-1: Methods specific to elastomeric compounds - Ozone resistance test, hot se

Non electrical test

methods for low voltage

energy cables

ICS 29.060.20

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+A1:2011

National foreword

This British Standard is the UK implementation of

EN 50396:2005+A1:2011 It supersedes BS EN 50396:2005, which is withdrawn

The start and finish of text introduced or altered by amendment is indicated in the text by tags Tags indicating changes to CENELEC text carry the number of the CENELEC amendment For example, text altered by CENELEC amendment A1 is indicated by !"

The UK participation in its preparation was entrusted by Technical Committee GEL/20, Electric cables, to Subcommittee GEL/20/17 Electric Cables - Low voltage

A list of organizations represented on this subcommittee can be obtained on request to its secretary

This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application

Compliance with a British Standard cannot confer immunity from legal obligations

This British Standard was

published under the authority

of the Standards Policy and

NORME EUROPÉENNE

EUROPÄISCHE NORM

CENELEC

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members

Ref No EN 50396:2005 E

ICS 29.060.20 Partially supersedes HD 21.2 S3:1997 + A1:2002 &

HD 22.2 S3:1997 + A1:2002

English version

Non electrical test methods for low voltage energy cables

Méthodes d'essais non électriques

pour les câbles d'énergie basse tension Nicht-elektrische Prüfverfahren für Niederspannungskabel und -leitungen

This European Standard was approved by CENELEC on 2005-07-01 CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard 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 Central Secretariat or to any CENELEC member

This European Standard 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 Central Secretariat has the same status as the official versions

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom

March 2011

The following dates were fixed:

– latest date by which the EN has to be implemented

at national level by publication of an identical

national standard or by endorsement (dop) 2006-07-01

– latest date by which the national standards conflicting

with the EN have to be withdrawn (dow) 2008-07-01

Foreword to amendment A1

This amendment was prepared by the Technical Committee CENELEC TC 20, Electric cables

The text of the draft was submitted to the Unique Acceptance Procedure and was approved by CENELEC as amendment A1 to EN 50396:2005 on 2011-03-14

The following dates were fixed:

– latest date by which the amendment has to be implemented

at national level by publication of an identical

national standard or by endorsement (dop) 2012-03-14

– latest date by which the national standards conflicting

with the amendment have to be withdrawn (dow) 2014-03-14

Contents

Page

1 Scope 5

2 Normative references 5

3 General test requirements 6

3.1 Sampling 6

3.2 Pre-conditioning 6

3.3 Test temperature 6

3.4 Test values 6

4 General test methods for dimensions 6

4.1 Measurement of insulation thickness 6

4.2 Measurement of sheath thickness for circular cables 7

4.3 Measurement of sheath thickness for flat cables 7

4.4 Measurement of overall dimensions and ovality 8

5 Tests relating to marking and colouring 9

5.1 Durability 9

5.2 Green-and-yellow measurement 9

6 Tests for mechanical strength of cables 11

6.1 Static flexibility test 11

6.2 Two pulley flexing test 13

6.3 Three pulley flexing test 18

6.4 Bending test 19

6.5 Kink test 20

6.6 Wear resistance test 23

6.7 Snatch test 24

6.8 Test for separation of cores 25

7 Tests for resistance to heat 25

7.1 Test of the resistance to hot particles 25

7.2 Test for resistance to heat of textile braids 26

8 Chemical and related tests 28

8.1 Ozone resistance test 28

8.2 Solderability test for plain conductors 30

9 Tests specific to extensible leads 32

9.1 Extension test 32

9.2 Endurance test 33

9.3 Tests under fire conditions 35

10 Tests specific to thermoplastic polyurethane sheath 35

10.1 Determination of the saponifìcation value of the polyurethane sheath 35

10.2 Tear resistance test 37

10.3 Water resistance 38

Annex A (informative) Source of non-electrical test methods in EN 50396 40

Annex B (normative) Rounding of numbers 41

Annex C (informative) Table for the calculation of α 42

Annex D (normative) Special national conditions 44

Bibliography 45

Figure 1 - Measurement of sheath thickness (flat cable) 8

Figure 2a - Measurement of the green-and-yellow proportion 9

Figure 3 - Static Flexibility Test 12

Figure 4 - Flexing apparatus 17

Figure 6 - Bending Test Apparatus 20

Figure 7 - Kink test apparatus 22

Figure 8 - Arrangement for wear-resistance test 24

Figure 9 - Device for testing resistance to hot particles 26

Figure 10 - Apparatus for the test for resistance to heat of textile braid 27

Figure 11 - Example of a clamping device 30

Figure 12 - Modified flexing apparatus for extensible leads 34

Figure 13 - Modified flexing apparatus for short extensible leads 34

Figure 14 - Test piece 38

Figure 15 - Test piece before being placed in the jaws of the tensile testing machine 38

Table 1a - Mass of weight and diameter of pulleys – thermoplastic cables 14

Table 1b - Mass of weight and diameter of pulleys – Crosslinked cables 16

Table 2a - Current loadings – Thermoplastic cables 17

Table 2b - Current loadings – Crosslinked cables 17

Table 3 - Current loading and diameter of pulley wheels 18

Table 4 - Tensile force exerted by the weight and test currents 21

Table for the calculation of α (continued) 43

Table 1a - Mass of weight and diameter of pulleys – thermoplastic cables 44

Table 1b - Mass of weight and diameter of pulleys – Crosslinked cables 44

Table 2a - Current loadings – Thermoplastic cables 44

Table 2b - Current loadings – Crosslinked cables 44

Figure 2b - Measurement of the green-and-yellow proportion 10

Figure 5 - Modified carrier "C" 19

The content of EN 50396 is not, and will not be, restricted only to test methods for cables to

HD 21 and HD 22 Other test methods for harmonized LV cables may be included Furthermore, the use of test methods in EN 50396 for cables outside HD 21 and HD 22 is not prohibited, but it is strongly recommended that expert advice be taken before such use, or

before any proposal for incorporation into another standard

NOTE 2 T, S and R are defined in the relevant cable standard

The requirements to be met during or after the test are specified for the particular cable type

in the relevant cable standard However, some test requirements are obvious and universal, such as the fact that no cracks shall occur during ozone test, and these are stated in the particular test method

Test methods for use specifically in utility power cables are not covered by this EN They can

of the referenced document (including any amendments) applies

Publication Year Title

EN 60332-1-2 2004 Tests on electric and optical fibre cables under fire conditions -

Par1-2: Test for vertical flame propagation for a single insulated wire or cable - Procedure for 1 kW pre-mixed flame

EN 50395 2005 Electrical test methods for low voltage energy cables

EN 60695-11-5 2005 Fire hazard testing - Part 11-5: Test flames - Needle-flame test

method - Apparatus, confirmatory test arrangement and guidance

A1 1998 2001 Insulating and sheathing materials of electric and optical cables - Common test methods - Part 2-1: Methods specific to

elastomeric compounds - Ozone resistance test, hot set and mineral oil immersion test

3 General test requirements

3.1 Sampling

If a marking is indented in the insulation or sheath, the samples used for the tests shall be taken so as to include such marking

3.2 Pre-conditioning

All the tests shall be carried out not less than 16 h after the extrusion or cross-linking, if any,

of the insulating or sheathing compounds

Any test requirements which are given in this standard may be modified by the relevant cable standard to suit the needs of a particular type of cable

4 General test methods for dimensions

4.1 Measurement of insulation thickness

4.1.1 Procedure

The thickness of insulation shall be measured in accordance with 8.1 of EN 60811-1-1

Three samples shall be taken from the cable; each sample shall be separated from the next by a distance of at least 1 m

Conformity shall be checked on each core

For multicore cables, except for the test in 4.1 , not more than three cores (of different colours, if available) shall be tested unless otherwise specified

! "

If withdrawal of the conductor is difficult, it shall be stretched in a tensile testing machine or the piece of core shall be loosened by stretching or some other suitable means that does not damage the insulation The cores of flat non-sheathed cords shall not be separated

4.1.2 Evaluation of results

The mean of the 18 values (expressed in millimetres) obtained from the three pieces of insulation from each core shall be calculated to two decimal places and rounded off as given in Annex B, and this shall

be taken as the mean value of the thickness of insulation

The lowest of all values obtained shall be taken as the minimum thickness of insulation at any place

4.2 Measurement of sheath thickness for circular cables

4.2.1 Procedure

The thickness of the sheath for circular cables shall be measured in accordance with 8.2 of

EN 60811-1-1

One sample of cable shall be taken from each of three places, separated by at least 1 m

For flat cords the measurements shall be carried out in accordance with 4.3

4.2.2 Evaluation of results

The mean of all the values (expressed in millimetres) obtained from the three pieces of sheath shall be calculated to two decimal places and rounded off as given in Annex B, and this shall be taken as the mean value of the thickness of sheath

The lowest of all values obtained shall be taken as the minimum thickness of sheath at any place

4.3 Measurement of sheath thickness for flat cables

4.3.1 Measuring equipment

A measuring microscope or a profile projector shall be used, each instrument being capable of at least

10 x magnification The equipment shall have an accuracy of 0,01 mm In cases of dispute a microscope allowing a reading with an accuracy of 0,01 mm or a profile projector of at least 20 x magnification shall

be used

4.3.2 Preparation of test pieces

One sample of cable shall be taken from each of three places, separated by at least 1 m

After all materials inside the sheath have been removed, a test piece shall be prepared from each sample by cutting with a suitable device (sharp knife, razor blade, etc.) a slice of sheath along a plane perpendicular to the longitudinal axis of the cable If the sheath carries an indented marking, the test piece shall be taken so as to include such marking

The thinnest place on the sheath shall be measured Where this does not coincide with one of the designated measurement points shown in Figure 1, it shall be substituted for the closest such point, to give a total of six measurements

The measurements shall be made in millimetres to two decimal places

4.3.4 Evaluation of results

The mean of all the values (expressed in millimetres) obtained from the three pieces of sheath shall be calculated to two decimal places and rounded off as given in Annex B, and this shall be taken as the mean value of the thickness of sheath

The lowest of all values obtained shall be taken as the minimum thickness of sheath at any place

1

Key

1 minimum thickness

Figure 1 - Measurement of sheath thickness (flat cable)

4.4 Measurement of overall dimensions and ovality

The three samples taken in accordance with 4.1.1, 4.2.1 or 4.3.2 shall be used

For the measurement of flat cables with a major dimension exceeding 15 mm, a micrometer, a profile projector or similar equipment shall be used

4.4.1.2 Evaluation of results

The mean of the values obtained shall be taken as the mean overall dimensions

4.4.2 Procedure for ovality measurement

For checking the ovality of circular sheathed cables, two measurements shall be made at the same cross-section of the cable, covering the maximum and minimum values

5 Tests relating to marking and colouring

5.1 Durability

The durability of printed marking or of colour shall be checked by trying to remove the marking or colour by rubbing lightly 10 times with a piece of cotton wool or cloth soaked in water

Measure the distance d1 and the core diameter D (Figure 2a)

Figure 2a - Measurement of the green-and-yellow proportion

Calculate the value for sine α using the formula:

sin α =

D d1

d1 = the chord of the green segment

D = the mean value of the diameter calculated from three measurements at different angles

Calculate the percentage (G p) of green (or yellow) using the following formula:

100 360

Key

1 base colour 2 other colour

Figure 2b - Measurement of the green-and-yellow proportion

Calculate the percentage (G p) of green (or yellow) for each cross section using the following equation:

A T is the total sum of each of the angles of rotation through each of the portions of green (or yellow if appropriate)

5.2.3 Evaluation of results

Calculate the mean of the six measurements and round to the nearest integer

Compare the results with the requirement specified in the relevant cable standard

6 Tests for mechanical strength of cables

6.1 Static flexibility test

Clamp the ends of the sample vertically so that they remain vertical during the test, one end

in clamp A, the other in the movable clamp B which shall be at a distance L = 0,20 m from

clamp A

NOTE The cable should take approximately the shape indicated by Figure 3 (dotted lines)

Move the movable clamp B away from the fixed clamp A until the loop formed by the cable takes the shape, indicated in Figure 3 by the heavy outline, of the U enclosed wholly between two plumb lines through the clamps and set up tangentially to the external generatrix of the cable Measure the new

distance, L/ The cable shall then be turned in the clamps by 180°, and the test repeated

Calculate the mean value of L /

6.1.3 Pre-conditioning of non-conforming samples

Where the cable does not satisfy the requirement for L/, or in the case of dispute, the test shall be repeated after the following pre-conditioning

Wind the sample four times on and off a reel with a diameter approximately 20 times the outer diameter

of the cable Each time the sample shall be turned through 90°, for round cables or, in the case of flat cables, through 180°

After this pre-conditioning, the sample shall be subjected to the test described in 6.1.2

6.2 Two pulley flexing test

6.2.1 General

The applicability of this test is given in the relevant cable standard

NOTE Normally this test should not be applied to:

- tinsel cords;

- single core cables with flexible conductors for fixed wiring;

- multi-core flexible cables having conductors of nominal cross-sectional area greater than 2,5 mm 2 for thermoplastic cables, or greater than 4 mm 2 for crosslinked cables;

- cables having more than 18 cores laid up in more than two concentric layers

6.2.2 Apparatus

This test shall be carried out by means of the apparatus shown Figure 4 This apparatus consists of a carrier C, a driving system for the carrier and four pulley wheels for each sample of cable to be tested The carrier C supports two pulley wheels A and B, which are of the same diameter The two fixed pulley wheels, at either end of the apparatus, may be of a different diameter from pulley wheels A and B, but all four pulley wheels shall be so arranged that the sample is horizontal between them The carrier makes cycles of forward and backward movements over a distance of 1 m at an approximately constant speed

of 0,33 m/s between each reversal of the direction of movement

The pulley wheels shall be made of metal Pulley wheels with a semi-circular shaped groove shall be used for testing circular cables and pulley wheels with a flat groove for testing flat cables The restraining clamps D shall be fixed so that the pull is always applied by the weight from which the carrier is moving away The distance from one restraining clamp to its support, while the other clamp is resting on its support, shall be a maximum of 50 mm

The driving system shall be such that the carrier reverses smoothly and without jerks when it changes from one direction of movement to the other

6.2.3 Sample preparation

A sample of flexible cable about 5 m long shall be stretched over the pulley wheels, as shown in Figure 4, each end being loaded with a weight The mass of this weight and the diameter of pulley wheels A and B shall be as given for the particular cable type (Table 1a for thermoplastic cables or Table 1b for crosslinked cables as appropriate)

6.2.4 Current loading of cores

During the flexing test the cable sample shall be loaded with the current specified in Table 2a or Table 2b for the particular cable type as follows:

- 2 core and 3 core cables: all cores shall be loaded fully

- 4 core and 5 core cables: three cores shall be loaded fully or all cores shall be

loaded with a current of In amps, calculated according to the following formula:

where n = number of cores

I3 = full current according to the particular cable type

n

3I

=

The current loading shall be applied either through the electrical system used to apply the voltage between cores specified in 6.2.5, or through a separate current generator system (e.g current transformers) On cores which are not loaded, a signal current shall be applied Cables

having more than five cores shall not be loaded

6.2.5 Voltage between cores

For two-core cables and for light, sheathed three- and four-core cables, the voltage between the conductors shall be (230 ± 15) V a.c

For all other cables having three or more cores, a three-phase a.c voltage of 400 V ± 15% shall be applied to three conductors, any additional conductors being connected to the neutral Three adjacent cores shall be tested; in the case of a multi-layer construction they shall be taken from the outer layer

6.2.6 Fault detection

The flexing apparatus shall be constructed so that it will detect and stop if any of the following occur during the flexing test:

− interruption of the test current;

− short circuit between the cores;

− short circuit between the test sample and the pulley wheels (flexing apparatus)

Table 1a - Mass of weight and diameter of pulleys – thermoplastic cables

Types of flexible cables Number

of cores (2)

Nominal cross sectional area

Mass of weight

Diameter of pulleys (1)

Light polyvinyl chloride sheathed cord

Ordinary polyvinyl chloride sheathed cord

Oil-resistant polyvinyl chloride sheathed

0,5 1,0 1,0 1,0 1,5

0,5 1,0 1,0 1,0 1,5

0,5 1,0 1,0 1,5 1,5

Table 1a - Mass of weight and diameter of pulleys – thermoplastic cables (continued)

Types of flexible cables Number

of cores (2)

Nominal cross sectional area

Mass of weight

Diameter of pulleys (1)

0,75

1 1,5 2,5

1,0 1,0 1,0 1,5 2,0

1,0 1,5 1,5 2,0 3,5

1,0 1,5 1,5 2,5 3,5

1,5 2,0 3,0 4,0 7,0

2,0 3,0 4,0 6,0 7,5

(1) Diameter measured at the lowest point of the groove

(2) Cables with numbers of cores between 7 and 18, but not specified in this table, are preferred' cable types They may be tested using the mass of weight and the pulley diameter for the same conductor size at the next highest specified number of cores

'non-Table 1b - Mass of weight and diameter of pulleys – Crosslinked cables

Types of flexible cable Number of cores

1,0 1,0 1,0

80

80

80 Ordinary rubber sheathed cord

and flexible cable

Ordinary polychloroprene or

other equivalent synthetic

elastomer sheathed cord and

flexible cable

Heavy polychloroprene or

other equivalent synthetic

rubber sheathed flexible cable

1,5 2,5

4

1,0 1,0 1,5 2,5

4

1,0 1,5 2,0 3,0

4

1,5 1,5 2,5 3,5

4

1,5 2,5 3,0 4,0

200

200

(2) Diameter measured at the lowest point of the groove

(1) For core numbers above five and below 18 not given in this table the pulley diameter shall be 200 mm and the mass of weight shall be eight to 10 times the weight of 1m of the cable to be tested

Table 2a - Current loadings – Thermoplastic cables Nominal cross-sectional area

45 ˚

Key

B pulley B D restraining clamps

Figure 4 - Flexing apparatus

6.3 Three pulley flexing test

The test shall be carried out in accordance with 6.2 with the following modifications

a) Carrier The apparatus described in 6.2.2 shall have a modified carrier (C), as shown in Figure 5

b) Pulley wheels and current loading of cores The three pulley wheels of modified carrier (C) shall be

of equal diameter to each other in accordance with the Table 3 Each core shall be fully loaded with the current given in Table 3

c) Speed of carrier The constant speed of the modified carrier (C) shall be approximately 0,1 m/s

d) Mass of weights The mass of the weights applied to stress the conductor as described in 6.2.3

shall be such as to apply a force of 28 N/mm2 of conductor cross-section

Table 3 - Current loading and diameter of pulley wheels

Cable type Current loading Diameter of

pulley wheels

A mm

Number of cross

Nominal conductor cross sectional area

Figure 5 - Modified carrier "C"

6.4.2 Requirement

The requirement shall be given in the relevant cable standard

If the sample does not comply with the requirement, the test shall be repeated with two additional samples, both of which shall then comply

4

3

2 1

Dimensions in millimetres

Key

1 means for fixing sample 3 sample

2 axis of oscillation 4 weight

Figure 6 - Bending test apparatus

6.5 Kink test

6.5.1 Applicability

The test is applicable to 2 and 3 core sheathed cords, with conductor cross-sectional areas up

to and including 1,5 mm²

6.5.2 Apparatus

The test shall be carried out by means of a tensile strength testing machine or equivalent apparatus

There shall be two clamps for fixing the cord The upper clamp shall be capable of upwards and downwards movement The lower clamp shall allow free movement in the vertical direction, but shall be prevented from twisting about its vertical axis so that no change to the torsion in the cord is introduced during the test The arrangement is shown in Figure 7

6.5.3 Sample

The test cord sample shall have a length of approximately 1 m The cord shall be twisted three times, as shown in position 1 (starting position only) of Figure 7, and then fixed in the upper and lower clamps such that the starting distance between the clamps is 200 mm The total extended length of cord between the two clamps shall be approximately 800 mm, as shown in position 2 (extended position) of Figure 7

Four samples shall be prepared for testing, two with the twists applied in a clockwise direction and two in

an anticlockwise direction

NOTE In order to prevent the tensioning weight reaching the top of its guide and either hitting an end-stop or rising clear of the guide, it is strongly recommended that the following sample preparation should be carried out: a) The three twists should be set in the sample and temporarily secured with adhesive tape before presenting the sample to the equipment

b) The ends of the sample should be located in the fixing clamps and the adhesive tape should then be removed c) The fixing clamps should be slowly moved apart to ensure that the sample achieves a straight orientation when the clamps are fully extended, with the tensioning weight still in the guide and satisfying the 50 mm lift specified

in 6.5.4 When the fully extended position is reached, the tensioning weight should not make contact with any end-stop positioned in the guide

d) If this straight orientation is not achieved, up to 30 slow test cycles should be performed during which the sample should be manipulated so that the twists are distributed more evenly over the sample length and so that

a knot does not occur during the initial phase of the test procedure

6.5.4 Test procedure

The lower clamp shall be loaded with a weight, sufficient to exert the tensile force given in Table 4

Each conductor of the cord shall be loaded with a current, as specified in Table 4 The current may be at

a low voltage

The moveable upper clamp shall make upwards and downwards movements at the rate of nine complete cycles per minute (one complete cycle equals one upwards and downwards movement) The distance of travel for each movement (upwards and downwards) shall be 650 mm

When the upper clamp is fully raised the weight attached to the bottom clamp shall have been raised by about 50 mm (see Figure 7, position 2)

Table 4 - Tensile force exerted by the weight and test currents Nominal cross-sectional

A

0,75 1,0 1,5

Dimensions in millimetres

Key

1 fixing clamp 6 fixing clamp

2 up and down movements 7 anti-torsion guidance

4 3 x twisted 9 position 1 (starting point)

5 one twist 10 position 2

Figure 7 - Kink test apparatus