Railway applications - Railway rolling stock cables having special fire performance - Test methods

This document specifies special test methods applicable to cables, and their constituent insulating and sheathing materials, for use in railway rolling stock. Such cables are specified in the various parts of the EN 50264 series, EN 50306 series and EN 50382 series. Other test methods required for railway rolling stock cables and their insulating and sheathing materials are listed in Annex A.

Bahnanwendungen - Kabel und Leitungen für Schienenfahrzeuge mit verbessertem Verhalten im Brandfall - Prüfverfahren

Applications ferroviaires - Câbles pour matériel roulant ferroviaire ayant des performances particulières de comportement au feu - Méthodes d'essais

Le présent document définit les méthodes d'essais spéciaux relatives aux câbles et à leurs matériels d'isolation et de gainage constitutifs, utilisés dans le matériel roulant ferroviaire. Ces câbles sont spécifiés dans les différentes parties de la série EN 50264, de la série EN 50306 et de la série EN 50382. D'autres méthodes d’essai exigées pour les câbles de matériel roulant ferroviaire et leurs matériels d'isolation et de gainage correspondants sont indiquées à l’Annexe A.

Železniške naprave - Kabli v železniških vozilih s posebno požarno odpornostjo - Preskusne metode

General Information

Status
Published
Publication Date
19-Mar-2020
Technical Committee
Current Stage
6060 - Document made available
Due Date
20-Mar-2020
Completion Date
20-Mar-2020

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SLOVENSKI STANDARD
SIST EN 50305:2020
01-junij-2020
Nadomešča:
SIST EN 50305:2002
Železniške naprave - Kabli v železniških vozilih s posebno požarno odpornostjo -
Preskusne metode

Railway applications - Railway rolling stock cables having special fire performance - Test

methods
Bahnanwendungen - Kabel und Leitungen für Schienenfahrzeuge mit verbessertem
Verhalten im Brandfall - Prüfverfahren
Applications ferroviaires - Câbles pour matériel roulant ferroviaire ayant des
performances particulières de comportement au feu - Méthodes d'essais
Ta slovenski standard je istoveten z: EN 50305:2020
ICS:
13.220.40 Sposobnost vžiga in Ignitability and burning
obnašanje materialov in behaviour of materials and
proizvodov pri gorenju products
29.060.20 Kabli Cables
45.060.01 Železniška vozila na splošno Railway rolling stock in
general
SIST EN 50305:2020 en

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

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SIST EN 50305:2020
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SIST EN 50305:2020
EUROPEAN STANDARD EN 50305
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2020
ICS 29.060.20; 45.060.01 Supersedes EN 50305:2002 and all of its amendments
and corrigenda (if any)
English Version
Railway applications - Railway rolling stock cables having
special fire performance - Test methods

Applications ferroviaires - Câbles pour matériel roulant Bahnanwendungen - Kabel und Leitungen für

ferroviaire ayant des performances particulières de Schienenfahrzeuge mit verbessertem Verhalten im

comportement au feu - Méthodes d'essais Brandfall - Prüfverfahren

This European Standard was approved by CENELEC on 2019-12-30. 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 CEN-CENELEC

Management Centre 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 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 50305:2020 E
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SIST EN 50305:2020
EN 50305:2020 (E)
Contents Page

European foreword ...................................................................................................................................4

Introduction ...............................................................................................................................................5

1 Scope ...............................................................................................................................................6

2 Normative references .......................................................................................................................6

3 Terms and definitions .......................................................................................................................7

4 Applicability, sampling, test-piece preparation and test conditions ..................................................7

4.1 Applicable tests ......................................................................................................................7

4.2 Classification of tests ..............................................................................................................7

4.3 Sampling .................................................................................................................................7

4.4 Test-piece preparation ............................................................................................................7

4.5 Test conditions .......................................................................................................................7

4.5.1 Ambient temperature ......................................................................................................7

4.5.2 Tolerance on temperature values ..................................................................................7

4.5.3 Frequency and waveform of power frequency test voltages ..........................................8

4.5.4 Pre-conditioning .............................................................................................................8

5 Mechanical tests ...............................................................................................................................8

5.1 Impact test at low temperature ...............................................................................................8

5.2 Abrasion resistance ................................................................................................................8

5.3 Notch propagation ..................................................................................................................9

5.4 Pliability (only applicable for cable in according to EN 50306 series) ................................. 10

5.5 Strippability and adhesion of insulation (only applicable for cable in according to

EN 50306 series) ................................................................................................................. 11

5.5.1 Strippability .................................................................................................................. 11

5.5.2 Adhesion ..................................................................................................................... 11

5.6 Dynamic cut-through (only applicable for cable in according to EN 50306 series) ............. 11

6 Electrical tests ............................................................................................................................... 12

6.1 Electrical resistance of conductors ...................................................................................... 12

6.2 Voltage test on completed cable ......................................................................................... 12

6.2.1 Cable without metallic layer......................................................................................... 12

6.2.2 Cable with one or more metallic layers ....................................................................... 12

6.3 Voltage test on sheath ......................................................................................................... 12

6.4 Insulation resistance ............................................................................................................ 13

6.4.1 Test at ambient temperature ....................................................................................... 13

6.4.2 Test at elevated temperature ...................................................................................... 13

6.5 Spark test............................................................................................................................. 13

6.5.1 General ........................................................................................................................ 13

6.5.2 Method......................................................................................................................... 13

6.6 Surface resistance ............................................................................................................... 13

6.7 DC stability........................................................................................................................... 14

6.8 Dielectric strength ................................................................................................................ 15

7 Ageing and thermal tests............................................................................................................... 15

7.1 Compatibility ........................................................................................................................ 15

7.2 Long term ageing ................................................................................................................. 15

7.2.1 General ........................................................................................................................ 15

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SIST EN 50305:2020
EN 50305:2020 (E)

7.2.2 Summary of test method ............................................................................................. 15

7.2.3 Apparatus .................................................................................................................... 16

7.2.4 Method......................................................................................................................... 16

7.3 Long term ageing for sheath and insulation where winding test is not possible ................. 18

7.4 Ozone resistance ................................................................................................................. 18

7.4.1 Electrical test ............................................................................................................... 18

7.4.2 Non-electrical test ........................................................................................................ 18

7.5 Pressure test at high temperature ....................................................................................... 20

7.6 Shrinkage test for insulation ................................................................................................ 20

7.7 Stress cracking test ............................................................................................................. 20

7.7.1 General ........................................................................................................................ 20

7.7.2 Preparation of test assemblies .................................................................................... 20

7.7.3 Determination of the 168 h thermal ageing test temperature ...................................... 21

7.7.4 Test method ................................................................................................................ 22

8 Tests in fluids, including water ...................................................................................................... 22

8.1 Mineral and fuel oil resistance ............................................................................................. 22

8.2 Acid and alkali resistance .................................................................................................... 22

8.3 Water absorption of sheath ................................................................................................. 22

9 Fire performance tests .................................................................................................................. 23

9.1 Flame propagation ............................................................................................................... 23

9.1.1 Cables with overall diameter greater than 6 mm and less than 12 mm ...................... 23

9.1.2 Cables with overall diameter not greater than 6 mm .................................................. 23

9.2 Toxicity ................................................................................................................................. 23

9.2.1 General ........................................................................................................................ 23

9.2.2 Qualitative analysis for nitrogen and sulfur using molten sodium ............................... 24

9.2.3 Quantitative analysis ................................................................................................... 24

9.2.4 Index calculation .......................................................................................................... 26

10 Miscellaneous tests ....................................................................................................................... 27

10.1 Durability of marking ............................................................................................................ 27

10.2 Blocking of cores ................................................................................................................. 27

10.3 Determination of halogen content ....................................................................................... 27

Annex A (informative) List of other test methods applicable to rolling stock cables ............................ 28

Annex B (normative) Procedure for checking the efficacy of the method of spark testing (with

reference to 6.5) ............................................................................................................................ 29

Annex C (informative) Long term ageing test – Significance and use ................................................. 31

Annex D (informative) Illustration of an Arrhenius plot ......................................................................... 32

Annex E (normative) Analysis methods for toxicity .............................................................................. 33

Annex F (normative) Halogen-Free ...................................................................................................... 39

Annex G (normative) Determination of halogens – Elemental test ...................................................... 41

Bibliography ........................................................................................................................................... 43

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SIST EN 50305:2020
EN 50305:2020 (E)
European foreword
This document (EN 50305:2020) has been prepared by CLC/TC 20, “Electric cables”.
The following dates are fixed:
• latest date by which this document has (dop) 2020-12-30
to be implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2022-12-30
standards conflicting with this document
have to be withdrawn

This document supersedes EN 50305:2002 and all of its amendments and corrigenda (if any).

EN 50305:2020 includes the following significant technical changes with respect to EN 50305:2002:

— a new cable standard EN 50382 series has been added to EN 50305;

— the long term ageing test part is improved and adapted to the whole range of products;

— the requirements are now clearly described and give more information for the test laboratories;

— the definition of “halogen free” in Annex F and the determination of halogens element test in

Annex G are moved from the product standard (EN 50306 series) to EN 50305.

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.

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SIST EN 50305:2020
EN 50305:2020 (E)
Introduction

The railway industry is generally concerned with the movement of people as well as goods. It is

therefore essential that a high level of safety is achieved, even when failures occur which could

involve fire, howsoever caused, affecting railway rolling stock.

Hence, it is necessary to provide cables for use in railway environments which minimize the hazard to

people when a fire may damage the cable, irrespective of whether the fire is caused by an external

source or from within the electrical system.

European Standard series EN 50264, EN 50306 and EN 50382 specify cables, which, in the event of

fire, will limit risk to people and improve the safety on railways in general. They cover cables based on

halogen free materials, for use in railway rolling stock.

A separate European Standard, the EN 50264 series covers cables for similar applications up to

3,6/6 kV rating with a conductor temperature at 90 °C, but with standard wall and medium wall

thicknesses of both insulation and sheath, and provides for a maximum conductor size of 400 mm .

A separate European Standard, the EN 50382 series covers cables for similar applications up to

3,6/6 kV rating with a conductor temperature at 120°C and 150°C, and provides for a maximum

conductor size of 400 mm .

The EN 50306 series covers a range of sheathed and unsheathed cables with thin wall insulation, and

is restricted to a rating of 300 V to earth and a maximum conductor size of 2,5 mm .

This document gives particular test methods applicable to the cables at present covered by the

EN 50264 series, EN 50306 series and EN 50382 series.
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SIST EN 50305:2020
EN 50305:2020 (E)
1 Scope

This document specifies special test methods applicable to cables, and their constituent insulating and

sheathing materials, for use in railway rolling stock. Such cables are specified in the various parts of

the EN 50264 series, EN 50306 series and EN 50382 series.

Other test methods required for railway rolling stock cables and their insulating and sheathing

materials are listed in Annex A.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments)

applies.

EN 50264-1, Railway applications - Railway rolling stock power and control cables having special fire

performance - Part 1: General requirements

EN 50306-1, Railway applications - Railway rolling stock cables having special fire performance - Thin

wall - Part 1: General requirements

EN 50382-1, Railway applications - Railway rolling stock high temperature power cables having

special fire performance - Part 1: General requirements

EN 60216-1, Electrical insulating materials - Thermal endurance properties - Part 1: Ageing

procedures and evaluation of test results
EN 60228, Conductors of insulated cables

EN 60332-3-25, Tests on electric and optical fibre cables under fire conditions - Part 3-25: Test for

vertical flame spread of vertically-mounted bunched wires or cables - Category D

EN 60754-1, Test on gases evolved during combustion of materials from cables - Part 1:

Determination of the halogen acid gas content

EN 60754-2:2014, Test on gases evolved during combustion of materials from cables - Part 2:

Determination of acidity (by pH measurement) and conductivity

EN 60811 (all parts), Electric and optical fibre cables - Test methods for non-metallic materials

EN 62230, Electric cables - Spark-test method

ISO 6349:1979, Gas analysis - Preparation of calibration gas mixtures - Permeation method

ISO 8458-2, Steel wire for mechanical springs — Part 2: Patented cold-drawn non-alloy steel wire

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SIST EN 50305:2020
EN 50305:2020 (E)
3 Terms and definitions

For the purposes of this document, the terms and definitions given in EN 50264-1, EN 50306-1 and

EN 50382-1 apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
4 Applicability, sampling, test-piece preparation and test conditions
4.1 Applicable tests

Tests applicable to each type of cable are given in the particular cable standard.

4.2 Classification of tests

The classification of tests is given in the general requirements of the relevant cable standard.

4.3 Sampling

The size and number of samples for each particular test is given either in this document or the

relevant cable standard.
4.4 Test-piece preparation

The preparation of test pieces shall be as described in the particular test method or in the cable

standard.

NOTE Attention is drawn to the fact that some insulation systems used for railway cables are composites

(multilayer). In such cases special preparation techniques and requirements are given in the particular cable

standard.
4.5 Test conditions
4.5.1 Ambient temperature

Tests shall be made at an ambient temperature within the range 5 °C to 35 °C, unless otherwise

specified in the details for the particular test.
4.5.2 Tolerance on temperature values
The tolerances which shall apply to the temperature values are given in Table 1.
Table 1 — Tolerances for temperature values
Specified Tolerance
temperature (T)
°C °C
−40 ≤ T ≤ 0 ±2
0 < T ≤ 50 According to relevant clause
50 < T ≤ 150 ±2
T > 150 ±3
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SIST EN 50305:2020
EN 50305:2020 (E)
4.5.3 Frequency and waveform of power frequency test voltages

Unless otherwise specified, the test voltage shall be a.c. 49 Hz to 61 Hz of approximately sine-wave

form; the ratio peak value/r.m.s. value being equal to √2 with a tolerance of ± 7 %.

The values quoted are r.m.s. values.
4.5.4 Pre-conditioning

Unless otherwise stated 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.
5 Mechanical tests
5.1 Impact test at low temperature

The impact test in accordance with EN 60811-506:2012, 8.5 shall be used except that the mass of

hammer, intermediate test piece and height of drop shall be as given in Table 2.
Table 2 — Parameters for impact test at low temperature
Cable Mass of Mass of intermediate Height of
diameter (D) hammer test piece drop
mm g g mm
D ≤ 15 1 000 200 100
15 < D ≤ 25 1 500 200 150
D > 25 2 000 200 200

The inside and outside of the sheath and the insulation of unsheathed cables shall then be examined

with normal or corrected vision, without magnification. The insulation of sheathed cables shall be

examined on the outside only.
5.2 Abrasion resistance

The test shall be carried out at a temperature of (20 ± 5) °C, using a machine similar to that shown in

Figure 1.

The cutting edge shall be either a polished steel spring wire needle of (0,45 ± 0,01) mm diameter of

material according to ISO 8458-2, held in a suitable support (Figure 1 b)), or a rectangular shaped

steel blade (Figure 1 a)) mounted at 90° to the axis of the cable. The setting shall be arranged so as to

wear the surface of the core or cable lengthwise over a distance of 10 mm to 20 mm, with a frequency

of (55 ± 5) cycles per minute. The machine shall be fitted with a counter which shall stop automatically

when the cutting edge touches the conductor or electrical screen.

For cables of diameter less than or equal to 6 mm the needle shall be used, and for cables with

diameter greater than 6 mm the steel blade shall be used, unless otherwise specified in the particular

cable standard.
The load on the cutting edge shall be defined in the cable standard.
The test specimen shall consist of a single 0,75 m sample of core or cable.
The test specimen shall be held securely on the plate by 2 cable clamps.

Each test specimen shall undergo four tests. After each single test it shall be moved approximately

100 mm and turned by a 90° angle, clockwise.

In the case of 2 core cables, 3 core cable or those cables not substantially circular, the cutting edge

should be applied to the highest points on the circumference of the cable.
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SIST EN 50305:2020
EN 50305:2020 (E)

Each test is finished when the cutting edge touches the conductor or electrical screen.

The measure of abrasion resistance shall be the average value of the number of cycles in the four

tests.
Dimensions in millimetres
a) Detail X b) Detail Y
(edges not rounded; free of burr)
Key
1 Stroke generator 7 Fastening screw
2 Stroke 8 Blade reamer
3 Loading weight 9 Shoulder of sufficient depth to
clear insulation
4 Clamp
5 Test specimen 10 Cutting edge - needle
6 Supporting plate 11 Cable under test
Figure 1 — Test arrangement for abrasion of insulation and sheath
5.3 Notch propagation

Three samples of the cable shall be notched, to a depth of 0,05 mm of the insulation or sheathing, at

four points equally spaced with respect to one another around the circumference and 25 mm apart

along the length, and in a plane mutually perpendicular to the conductor.

In the case of 2 core cable, 3 core cable or those cables not substantially circular, the notches should

be made at the highest points on the circumference of the cable.

One of the samples shall be conditioned at −15 °C, one at ambient temperature and one at 85 °C, in

all cases for 3 h, after which time they shall be wound on to a mandrel, (3 ± 0,3) times the minimum

specified diameter of the cable, whilst at the conditioning temperature. The notched sample shall be

wrapped around the mandrel such that at least one notch is on the outside of the wrapped cable.

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SIST EN 50305:2020
EN 50305:2020 (E)

The sample shall be allowed to return to ambient temperature and then subjected to the voltage test

given in 6.2 but at half the rated voltage U .
5.4 Pliability (only applicable for cable in according to EN 50306 series)

From a single coil of cable cut consecutive test specimen lengths, each of approximately 200 mm.

Suspend each specimen vertically for 24 h in an oven with a mass attached to its free end. The

applied mass and oven temperature shall be as stated in the cable specification. Immediately after

removal from the oven, store the specimens at the temperature, relative humidity and period of time

specified in the cable specification.

Test each specimen using the test rig shown in Figure 2; the diameter of the mandrel in the test rig

shall be as the minimum bend diameter unless specified in the cable specification. Gradually apply a

mass to the cable, at the position shown in Figure 2, sufficient to bend the cable downwards through

(90 ± 1)°.

Ensure that the specimen remains in this position for 5 min and record the mass. After this time,

remove the mass and allow the specimen to recoil towards its original position. At a time 5 min after

removal of the mass, record the recoil angle.
Dimensions in millimetres / scale in degrees
Key
1 Clamp
2 Mandrel
3 Test specimen
4 Mass container
5 Recoil angle
Figure 2 — Pliability test rig
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SIST EN 50305:2020
EN 50305:2020 (E)

5.5 Strippability and adhesion of insulation (only applicable for cable in according to

EN 50306 series)
5.5.1 Strippability

Stripping of 5 mm of insulation from each end of a 50 mm sample shall be easily carried out with

normal stripping pliers.
5.5.2 Adhesion

Three test specimens, each of 50 mm length, shall be cut at regular intervals from a test sample of

3 m of core or cable.

On each specimen the insulation shall be cut 5 mm and 30 mm from one end. The insulation shall be

stripped from the cuts to each end, so that insulation is left intact in-between the two cuts. The

conductor shall then be passed through a calibrated hole the diameter of which is that of the conductor

+ 0,05 mm (see Figure 3).

Using a pulling speed of (100 ± 10) mm/min a force shall be applied to the conductor until it slips

inside the insulation. The force (F) required to produce the slippage shall be recorded.

Dimensions in millimetres
Figure 3 — Assembly for adhesion test

5.6 Dynamic cut-through (only applicable for cable in according to EN 50306 series)

A tensile tester (or equivalent apparatus) shall be operated in a compression mode and shall be

equipped with a means to record the force necessary to drive the needle cutting edge (see

Figure 1 b)) through the insulation or sheath of a finished sample of cable. A low voltage detection

circuit, designed to stop the tester when the edge cuts through the cable insulation or sheath and

contacts the conductor or electrical screen, shall be attached.

Carry out the test at the temperature specified in the individual cable specification. The force on the

cutting edge driving it through the insulation or sheath shall be increased at the constant rate as

specified in the product standard until contact with the conductor or metallic screen occurs. Perform

four tests on each test sample, and record the force measured at electrical contact. Move the sample

forward a minimum of 25 mm and rotate 90° clockwise between each test.

In the case of 2 core cables, 3 core cable or those cables not substantially circular, the cutting edge

should be applied to the highest points on the circumference of the cable.
The average of the four results shall not be less than the specified minimum.
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