In engineering design don't require the use of class A fireproof Flexible Cable, because NH - YJV or NH - VV generally can not meet the class A demand, although mineral insulated cable fireproof performance is excellent, but the cost is much higher than ordinary fireproof cables, more strict to the requirement of the construction, the other being single core cable, relative N for PE, distance between different, single phase short circuit, grounding short circuit impedance (reactive) have certain differences.
Five, the nouns Oxygen index: refers to under prescribed conditions, solid material in oxygen, nitrogen mixed flow, the minimum necessary to sustain the steady combustion oxygen content.High oxygen index Security alarm cable said material is not easy to burn, low oxygen index said material easy to burn