How to distinguish the flame retardant and fire resistance of cable?

Some electrical designers are not clear about the concept of flame-retardant cable and fire-resistant cable, and do not have a good understanding of the structure and characteristics of the two, so that they cannot correctly design and select these two kinds of cable according to the power supply requirements, and cannot correctly guide the laying and construction of these two kinds of cable when conducting design agency or supervision work on site.

1. What is flame-retardant cable?

Flame retardant cable refers to the cable that the sample is burned under specified test conditions and the flame spread is only within a limited range after the test fire source is removed, and the residual flame or residual burning can be extinguished by itself within a limited time. Its basic characteristics are: in the case of fire may be burned out and can not operate, but can prevent the spread of fire. Generally speaking, the cable in case of fire, can limit the combustion in the local scope, do not produce spread, keep all kinds of other equipment, avoid causing greater losses.

2. Structural characteristics of flame retardant cable

The structure of flame retardant cable is basically the same as that of ordinary cable, the difference lies in that its insulation layer, sheath, outer protective layer and auxiliary materials (wrapping and filling) are all or part of flame retardant materials.　　

3. What is fire-resistant cable?

Fire-resistant cable refers to: under the specified test conditions, the sample is burned in the flame, in a certain time can still maintain the normal operation of the performance. Its basic characteristic is: the cable can still maintain the normal work of the line for a period of time under the condition of combustion. Generally speaking, in case of fire, the cable will not burn, the circuit is safer.

4. fire-resistant cable structure characteristics

The structure of fire-resistant cable is basically the same as that of ordinary cable, but the difference lies in that the conductor of fire-resistant cable adopts copper conductor with good fire-resistant performance (the melting point of copper is 1 083℃), and the fire-resistant layer is added between the conductor and the insulation layer. The refractory layer is made up of multiple layers of mica tape. The mica belt is the key to the fire resistance of the cable because of the large difference of the allowable working temperature of different cloud master belts.

The main difference

Therefore, the main difference between fire-resistant cable and fire-retardant cable is that fire-resistant cable can maintain normal power supply for a period of time when a fire occurs, while fire-retardant cable does not have this characteristic. This characteristic determines that fire-resistant cable plays an important role in modern urban and industrial buildings.

Because once the fire occurs, control, monitoring, guidance and alarm system power supply loop must maintain normal work. Therefore, the cable is mainly used in emergency power supply to user fire equipment, fire alarm equipment, ventilation and smoke exhaust equipment, guide lights, emergency power sockets, emergency elevators and other power supply loops.