Appendix 6 :
Flame -retardant grade
In the horizontal test , the sample should burn slowly , the burning speed of less than 3mm thickness sample can not surpass 3 inches /minute (76mm/ minute), and the burning of more than 3mm thickness samples can not surpass 1.5 inches/minute (38mm/minute ), the product with above -mentioned burning speed  can get UL approval.
UL 94 V2
In the vertical test , the average self -extinguishing time can not surpass 25 minutes ( less than 30 seconds per time ) ,something that comes out from burning might light the below cotton . but the allowed burning time can not surpass 60 seconds.
UL 94 V1
In the horizontal test, the average self- extinguishing time can not surpass 25 seconds (less than 25 seconds per time ) ,something that comes out from burning is forbidden to light the below cotton , the allowed burning time can''''''''''''''''t surpass 60 seconds.
UL 94 V0
In horizontal test , the average self -extinguishing time can not surpass 5seconds( less than 10 seconds per time ), something that comes out from burning is forbidden to light the below cotton , the allowed burning time can not surpass 30 seconds.
The relative instructions of filling rate
In the process of protecting cable, we have to take the filling capacity of conduit into consideration, that is to say , the conduit can bear the capacity of cables or wires.
In any circumstances, we suggest maximum of filling capacity should be below 70% , ( we have to take the standard of processing the samples into consideration), which can avoid damaging from the friction of working wires in the hydraulic process .
Installing and fastening the cable
we suggest that it is necessary to fasten the cables protective system , fixed distance is allowed between 300mm- 500mm.you can adjust the fixed distance according to practical application and installation . For example , for the jumbo conduit , you should adopt the small fixed distance because it has added the capacity between cables and wires . We can provide you with the different protective products to meet your needs.
According to European standard EN 50343:2003-5.15 RAILWAY APPLICATION - ALL RAILCARS INSTALLATION RULES ,the fixed distance of fastening cable brackets should be 300mm (horizontal installation ) and 500mm( vertical installation)
Technical parameter of the electrical engineering