BS 6853 fire test to Electrical Device - Standard :
> BS 6853: Code of practice for fire precautions in the design and construction of passenger carrying trains
BS 6853 fire test to Electrical Device - Design
> Electrical protection
Creepage and clearance distances should be set with due regard for the propensity of the materials to track and with due regard for the voltage used and whether it is a.c. or d.c., so as to minimize the occurrence of electrical faults. Suitable electrical protection should be provided to ensure that the energy release rate on occurrence of a fault and the duration of the fault is minimized. This guidance applies to electrical power both as an ignition source and as a power output hazard when in the form of a power arc.
> Protection against power arcs
Suitable arc resisting barriers should be used to protect the passenger compartments with particular consideration being given to areas where faults are electrically unprotected other than by substation circuit breakers.
> Protection against high current circuit breaker output
Suitable shields should be provided to prevent any effluent from the train-borne circuit breaker acting as an ignition source for materials or debris and also to prevent the degradation of other systems such as cables which would increase the risk of ignition should they fail.
> Protection against sparks from current collectors
Suitable shields should be provided to prevent incandescent particles from current Collectors from acting as an ignition source for underbody materials and debris.
BS 6853 fire test to electrical device -Test method and requirement
> BS 6853 Table 7: Interior minor use materials of mass 100g to 500g
- BS EN ISO 4589-2:Fire test for Oxygen Index
- BS EN ISO 4589-3:Fire test for Temperature test
- BS 6853 Annex D:Fire test for Smoke Density
- BS 6853 Annex B:Fire test for Toxicity
> BS 6853 Table 7 - Requirement:
Test Method
|
Parameter
|
Vehicle Category
|
||
Ia
|
Ib
|
II
|
||
ISO4589-2
ISO4589-3 |
Oxygen Index (OI)
Flammability Temperature FT
|
34%
300℃
|
34%
300℃
|
28%
250℃
|
BS 6853 Annex D
|
Ao(Max.)
|
0.017
|
0.027
|
0.061
|
BS 6853 Annex B
|
R(Max.)
|
1.0
|
1.6
|
3.6
|
Fire test to electrical device for railway vehicle – Reference Standard
> BS EN ISO 4589-2:Plastics - Determination of Burning Behaviour by Oxygen Index - Part 2: Ambient-Temperature Test
> BS EN ISO 4589-3:Plastics - Determination of Burning Behaviour by Oxygen Index Part 3: Elevated-Temperature Test
> BS 6853 Annex D: smoke density
> BS 6853 Annex B: Toxicity