BS EN 50306-2:2020 Railway applications – Railway rolling stock cables having special fire performance – Thin wall Part 2: Single core cables
BS EN 50306-2:2020 pdf free.Railway applications – Railway rolling stock cables having special fire performance – Thin wall Part 2: Single core cables.
This document specifies requirements for, and constructions and dimensions of, single core cables, rated voltage U0! U = 300 /300 V, of the following type:
Unscreened (0,5 mm2 to 2,5 mm2 single core)
These cables are rated for occasional thermal stresses causing ageing equivalent to continuous operational life at a temperature of 105 °C. For standard cables, this is determined by the acceptance test defined in EN 50305, using accelerated long-term (5 000 h) thermal ageing indicating a 125 °C120 000 h temperature index. If the customer were to require lifetime predictions, this would be demonstrated based on the temperature index of the product as supplied by the manufacturer. The maximum temperature for short circuit conditions is 160 °C based on duration of 5 s.
Under fire conditions the cables exhibit special performance characteristics in respect of maximum permissible flame propagation (flame spread) and maximum permissible emission of smoke and toxic gases. These requirements are specified to permit the cables to satisfy Hazard Level 3 of EN 45545-1 and EN 45545-2.
EN 50306-2:2020 is expected to be used in conjunction with EN 50306-1:2020, General requirements.
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 10002-1, Metallic materials – Tensile testing – Par? 1: Method of test at ambient temperature
EN 45545-1, Railway applicattons – Fire protection on railway vehicles – Part 1: General
EN 50305:2020, Railway applications – Railway rolling stock cables having special fire performance – Test methods
EN 50306-1:2020, Railway applications – Railway rolling stock cables having special fire performance – Thin wall – Part 1: General requirements
EN 50334, Marking by inscription for the identification of cores of electric cables
EN 60332-1-2, Tests on electric and optical fibre cables under fire conditions – Part 1-2: Test for vertical flame propagation for a single insulated wire or cable – Procedure for 1 kWpre-mixed flame
EN 60811 (all parts), Electric and optical fibre cables – Test methods for non-metallic materials
EN 61034-2, Measurerment of smoke density of cables burning under defined conditions – Part 2: Test procedure and requirements
EN 62230, Electric cables – Spark -test method
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:llwww.iso.orglobp
— I EC Electropedia: available at http://www.electropedia.org/
4 Single-core cables
4.1 General
The cables shall conform to the applicable general requirements given in EN 50306-1:2020 and to the specific requirements of this Part 2.
Conformity with the requirements shall be checked by inspection and by the tests given in Table 4.
4.2 Marking and code designation
4.2.1 Marking of cable
Cables shall be marked with the following:
— Manufacturer’s name;
— EN reference;
— Voltage rating (U0);
— Conductor size;
— A code designation according for use of the cable (see 4.2.2).
For example:
XYZ EN 50306-2 300 V lxl,5 M
The marking shall conform to the requirements of EN 50306-1:2020, Clause 5.
4.2.2 Code Designation
The following letters shall be used as a code to identify the suitability of a particular cable with the Hazard Level 3 of EN 45545-1, and to indicate performance levels relating to low temperature and to oil and fuel resistance:
Hazard Level EN 45545-1 HL3
— low temperature I oil resistance C
— extra low temperature I oil resistance F
— low temperature I extra oil and fuel resistance J
— extra low temperature I extra oil and fuel resistance M
4.3 Core identification
4.3.1 Single core cables
The colour of the cores shall be white unless otherwise specified in the particular sections.
The colour shall be clearly identifiable and durable. Durability shall be checked by the test given in 10.1 of EN 50305:2020.
Conformity with these requirements shall be verified by visual examination.
4.3.2 Multicorelmultipair cables
Cores complying with EN 50306-2:2020 are used as components of multicore and multipair cables. e.g. in EN 50306-3:2020 or EN 50306-4:2020, In such cases the identification of the individual core in a cable or a pair shall be by numbers.
The numbers shall be printed in a colour, which contrasts with the core colour. The numbers on individual cores shall be spaced at a maximum of 25 mm apart.
The marking by numbers shall conform to EN 50334, unless otherwise specified. and conformity shall be checked by visual examination and measurement.
4.4 Rated voltage
The rated voltage recognized for the purposes of this standard shall be
U0 / U = 300/300 V
NOTE See EN 50355 and EN 50343 for further information.
4.5 Construction
4.5.1 Conductor
The conductor shall conform to the requirements given in Table 1. The wires shall be tin coated annealed copper.
When tested in accordance with EN 10002-1. the minimum elongation of conductors shall be 10 %.
4.5.2 Insulation system
The insulation system shall be manufactured from material as defined in 3.1 of EN 50306-1:2020 and shall meet the requirements of Clause 5 of this Part 2. The insulation shall be applied by extrusion. The insulation thickness shall conform to the specified value given in Table 1 and determined in accordance with EN 50306-1:2020, Annex A.
5 Tests
5.1 Definitions relating to tests
The definition of Type (T), Sample (5) and Routine (R) tests is as given in EN 50306-1:2020, Clause
3.
NOTE Tests dassilied as Sample (S) or Routine (R) could be required as part of any approval schemes.
It is recommended for the type approval for the full range (or a restricted range) of cables given in Table 1 two cables should be tested, one with the minimum overall diameter and one with the maximum overall diameter of the range defined.
5.2 Voltage test
The test shall be carried out in accordance with EN 50305:2020. 6.2.1, using either an AC or DC voltage and the following conditions:
— sample length 20 m
— voltage (AC) 2 kV
— voltage (DC) 4,8 kV
— duration of application 5 mm
— test temperature (20 ± 5) °C
At the conclusion of the test there shall be no breakdown of the insulation.
5.3 Insulation resistance
The test shall be carried out at 20 °C and at 90 °C in accordance wdh EN 50305:2020, 6.4.1 and
6.4.2.
The values obtained shall not be below those given in columns 2 and 3 of Table 2.
5.4 Dielectric strength
The test shall be carried out in accordance with EN 50305:2020. 6.8. using the following conditions:
— water temperature (20 ± 5) C
— immersion duration 1 h
— minimum breakdown voilage (AC) 4 kV
At the conclusion of the test there shall be no breakdown below the minimum voltage.
5.5 Spark test
The test shall be carried out in accordance with EN 50305:2020, 6.5 and EN 62230, using one of the following conditions:
a) AC (50 Hz):
<0,25 mm tabulated insulation thickness 3,0 kV
0,25 mm < 0,35 mm tabulated insulation thickness 4,0 kV
b) impulse:
<0,25 mm tabulated insulation thickness 8,0 kV
0,25 mm < 0,35 mm tabulated insulation thickness 8.0 kV.BS EN 50306-2 pdf download.
BS EN 50306-2:2020 Railway applications – Railway rolling stock cables having special fire performance – Thin wall Part 2: Single core cables