The design and installation of electrical cables and wiring should be such as to ensure minimization of the risk of fire due to internal heating of the cables or wiring or due to external exposure to sources of heat. When determining the size of cables, the following should be taken into account:
a) the grouping of wires, whether in conduits, trunking or free air;
b) ambient temperature, with particular reference to elevated local temperature during vehicle operation;
c) the normal and peak temperature rating of the cable;
d) the normal and peak power carried by the cable;
e) the magnitude and duration of the power which might be carried by the cable under fault conditions;
f) the proximity of other combustible materials.
BS 6853 fire test to cable for railway vehicle – Standard:
> BS 6853: Code of practice for fire precautions in the design and construction of passenger carrying trains.
BS 6853 fire test to cable for railway vehicle- Test Method and Requirement：
> Test Method（BS 6853 Clause 6 – Table 13 – Interior Cables）：
- BS 4066-3: Fire test to bunched cables
- BS 6853 Annex D: Smoke Density test to Cable
- BS 6853 Annex B: Toxicity test to cable
> BS 6853 fire test to interior cable - Requirement
|
Test Method
|
Parameter
|
Vehicle Category
|
||
|
Ia
|
Ib
|
II
|
||
|
BS 4066-3
|
Burn Length (Max)
|
2.5m
|
2.5m
|
2.5m
|
|
BS 6853 Annex D
Smoke Density
|
Ao(ON)
Ao(OFF)
|
Ao(ON)
Ao(FF)
|
Iax1.6
Iax1.6
|
Iax1.6
Iax1.6
|
|
BS 6853 Annex B
Toxicity
|
R(Max.)
|
1.0
|
1.6
|
3.6
|
> Test Method（BS 6853 Clause 6 – Table 14 – Exterior Cables）
- BS 4066-3: Fire test to bunched cables
- BS 6853 Annex D: Smoke Density test to Cable
- BS 6853 Annex B: Toxicity test to cable
> BS 6853 fire test to cable - Requirement
|
Test Method
|
Parameter
|
Vehicle Category
|
||
|
Ia
|
Ib
|
II
|
||
|
BS 4066-3
|
Burn Length (Max.)
|
2.5m
|
2.5m
|
2.5m
|
|
BS 6853 Annex D
Smoke Density
|
Ao(ON)
Ao(OFF)
|
Ao(ON)
Ao(OFF)
|
Iax1.6
Iax1.6
|
Iax1.6
Iax1.6
|
|
BS 6853 Annex B
Toxicity
|
R(Max)
|
1.0
|
1.6
|
3.6
|
BS 6853 fire test to cable for railway vehicle － Reference Standard
> BS 4066-3, Tests on electric cables under fire conditions - Part 3: Tests on bunched wires or cables.
> BS 6387, Specification for performance requirements for cables required to maintain circuit integrity under fire conditions.
> NF X 70-1002), Fire tests - Analysis of pyrolysis and combustion gases - Tube furnace method.
> DIN EN 50264-1: Railway applications - Railway rolling stock cables having special fire performance; Standard wall - Part 1: General requirements
> DIN EN 50266-2-4 Common Test Methods for Cables under Fire Conditions - Test for Vertical Flame Spread of Vertically-Mounted Bunched Wires or Cables Part 2-4: procedures – Category C
> DIN EN 50266-2-5 Common Test Methods for Cables under Fire Conditions - Test for Vertical Flame Spread of Vertically-Mounted Bunched Wires or Cables Part 2-5: procedures – Category D
> DIN EN 50305: Railway applications. Railway rolling stock cables having special fire performance. Test methods
> DIN EN 50306-1: Railway applications - Railway rolling stock cables having special fire performances - Thin wall - Part 1: General requirements
> DIN 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 kW pre-mixed flame
> DIN EN 60332-2-2 Tests on electric and optical fibre cables under fire conditions Part 2-2: Test for vertical flame propagation for a single small insulated wire or cable Procedure for diffusion flame;
> DIN EN 61034-1: Measurement of smoke density of cables burning under defined conditions Part 1: Test apparatus.