Fire-resistant cable means that under the specified test conditions, the sample is burned in the flame and the performance of normal operation can still be maintained within a certain period of time. Its fundamental characteristic is that the cable can still maintain the normal operation of the line for a period of time under the burning conditions.
Structural features <br> <br> resistant cable structure and substantially the same common cable is fire-resistant cable, except that the fire-resistant cable conductor using copper conductor good fire resistance (melting point of copper is 1083 deg.] C), and the conductor and insulation Increase the fire layer between layers. The refractory layer is wrapped by multi-layer mica tape. Because the allowable working temperature of different mica tapes varies greatly, the key to the fire resistance of cables is the mica tape.
Attentions when selecting (1) When fire-resisting cables are used in cable-dense cable tunnels, cable interlayers, or in flammable places such as near oil tanks and oil depots, Class A fire-resistant cables should be used first. In addition to the above cases and when the number of cables is small, Class B fire-resistant cables can be used.
(2) Fire-resistant cables are mostly used as power supply circuits for emergency power supplies and require normal operation in fire. As the ambient temperature rises rapidly during a fire, in order to ensure the transmission capacity of the line and reduce the pressure drop, for a circuit with a long power supply line and strictly limiting the allowable voltage drop, the section of the fire-resistant cable should be enlarged at least one step.
(3) Fire-resistant cables cannot be used as high-temperature cables.
(4) In order to reduce the failure probability of cable joints in fire accidents, the number of joints should be minimized during installation to ensure that the line can work normally in a fire. If you need to make branch wiring, handle the joints to prevent fire.
Structural features <br> <br> resistant cable structure and substantially the same common cable is fire-resistant cable, except that the fire-resistant cable conductor using copper conductor good fire resistance (melting point of copper is 1083 deg.] C), and the conductor and insulation Increase the fire layer between layers. The refractory layer is wrapped by multi-layer mica tape. Because the allowable working temperature of different mica tapes varies greatly, the key to the fire resistance of cables is the mica tape.
Attentions when selecting (1) When fire-resisting cables are used in cable-dense cable tunnels, cable interlayers, or in flammable places such as near oil tanks and oil depots, Class A fire-resistant cables should be used first. In addition to the above cases and when the number of cables is small, Class B fire-resistant cables can be used.
(2) Fire-resistant cables are mostly used as power supply circuits for emergency power supplies and require normal operation in fire. As the ambient temperature rises rapidly during a fire, in order to ensure the transmission capacity of the line and reduce the pressure drop, for a circuit with a long power supply line and strictly limiting the allowable voltage drop, the section of the fire-resistant cable should be enlarged at least one step.
(3) Fire-resistant cables cannot be used as high-temperature cables.
(4) In order to reduce the failure probability of cable joints in fire accidents, the number of joints should be minimized during installation to ensure that the line can work normally in a fire. If you need to make branch wiring, handle the joints to prevent fire.
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