Fire resistance cable can still maintain the normal work of the line for a period of time in the combustion conditions, that is to say in case of fire, fire will not suddenly burning, it can still maintain the normal power supply for a period of time. This characteristic determines the fire resistance cable plays an important role in the modern city and the industrial building, because once the fire occurs, the control, the surveillance, the guidance and the warning and so on system power supply circuit must maintain the normal work.
The main use of fire-resistant cable:
Fire resistant cable is mainly used in the emergency power supply to the users fire equipment, fire alarm equipment, ventilation and smoke exhaust equipment, guide lights, emergency power sockets, emergency elevators and other power supply circuit.
The staff should pay attention to the following problems when installing fire resistant cable:
1, when the fire-resistant cable used in cable dense cable tunnel, cable interlayer, or located in oil pipes, oil depots and other flammable places nearby, should first select a class fire-resistant cable. In addition to these conditions, and the number of cable configuration is less, should be used B class fire-resistant cable.
2, fire resistant cables are mostly used as emergency power supply circuit, requires the normal operation of fire. As a result of the fire when the ambient temperature rises rapidly, in order to ensure the transmission capacity of lines, reducing the pressure drop for the power supply line is long and strictly limit the allowable voltage drop of the loop should be at least a refractory cable amplifier.
3, fire-resistant cable can not be used as high temperature cable.
4, in order to reduce the probability of failure of cable joints in fire accidents, the number of joints should be reduced as far as possible in order to ensure the normal operation of the line in the fire. If you need to do branch wiring, deal with the joint fire.