The cause of fires caused by wires and cables is primarily due to overload, short circuit, excessive touch resistance and external heat source effects.
In the case of short-circuit, partial overheating, etc., and the external heat effect, the insulation resistance of the insulation data is reduced, the insulation ability is lost, and even the incineration is caused, thereby causing a fire.
1 The primary characteristics of wire and cable in fires are:
1.1 The fire temperature is generally between 800 °C and 1000 °C.
In the case of fire, the wire and cable will quickly lose the insulation ability, which will cause secondary electrical problems such as short circuit.
Therefore, causing greater losses.
1.2 The conductor cable has a large overload capability under the specified allowable current carrying capacity.
1.3 Under short-circuit conditions.
The conductor cable will cause the insulation data to melt, incinerate, and ignite the surrounding combustibles.
2 Analysis of fire protection function of wire and cable
Analysis of fire prevention mechanism
2.1 Flame Retardant Mechanism - Flame Retardant Power Cable
(1) Under the thermal effect of incineration reaction, the flame retardant located in the agglomerated phase differentiates and absorbs heat.
So that the temperature rise in the agglomerated phase slows down, delaying the thermal differentiation speed of the data.
(2) After the thermal decomposition of the flame retardant, the chain reaction reverberation free radical blocker is released.
Which interrupts the branch of the flame and the chain reaction, and slows down the opposite speed of the gas.
(3) Catalytic agglomerated phase heat differentiation solid phase product, the composition of the coking layer or foam layer strengthens the effect of these layered hard shells on resisting heat transfer.
(4) Under the thermal effect, the flame retardant exhibits an endothermic phase change, physically obstructing the temperature rise in the agglomerated phase.
2.2 Fire resistance mechanism - fire resistant power cable
(1) Participate in certain additives in the insulation and sheath materials of wire and cable, reduce the heat generated by the polymer, avoid polymer differentiation or promote insulation and sheathing.
Data carbonization constitutes a maintenance layer.
(2) Add a layer of mica glass ribbon and other inorganic insulation materials at the core.
And after the insulation and sheath layer are ignited by fire, the mica refractory belt wrapped around the conductor.
Maintenance and continuous power-on, so that the normal operation of the moment must be maintained during the fire.