Improvements Of Cable Burning Behavior By Using FM Bedding Compounds
Project A: Improvement of cable burning behavior tests according to CSA FT-4, UL 1685 and UL 1277 on vertical tray cables
The effect of replacing PP yarn filler and aramid tape by bedding componds has been shown in a large scale flame test (70.000 BTU, 21kW, 20 minutes). Test objects were two different cable constructions which differ in their XLPE insulation (VW-1 vs. non-VW-1).
CONCLUSION: Even after applying a halogenated XLPE VW-1 insulation material with a higher LOI, the cable construction shows a considerably improved fire behavior. The NEW cable system, including Melos bedding compound FM 0474/5, shows a drastically reduced total smoke value, compared to the ORIGINAL cable system which was build with a flammable PP yarn filler and an expensive aramid tape.
Project B: Improvement of cable burning behavior tests according to IEC 60332-3-24 on optical fibre cables
The following burning tests acc. to IEC 60332-3-24 compare the flame spread behavior of fibre optic cables in two alternative configurations. The original cable system has a relatively thick wall of HFFR sheathing. The test results are negative because the required flame spread value of 250 cm cannot be reached.
The new cable system has a relatively thin wall of the same HFFR sheathing compound as in the original cable system. The thickness of the outer sheathing layer has been reduced and bedding compound FM 0474/5 has been added, whilst keeping the outer diameter of the cable unchanged.
Project C: CPR tests on European Standard Power Cables (NHXMH)
Different copper cable constructions have been tested to determine the effect of higher flame retardant sheathing compounds (higher LOI) on flame spread results.
The above example shows that a sheathing compound with a higher LOI hardly improves the flame spread. The same tests were also made on 3 different bedding compounds, using the sheathing compound of the above original cable system (Mecoline S TP 1003 F).
CONCLUSION: The CPR results have been considerably improved by using a highly flame retardant bedding compound.
The effect of a highly flame retardant bedding compound on flame spread has been tested and confirmed on two different cable constructions to demonstrate the impact of an extraordinary flame retardant bedding compound, FM 0474/5.