In recent years, the advantages of fire-resistant power cables have become more prominent. According to the survey, in the global power system fire accident, the proportion of power system power supply interruption caused by power cable fire has an increasing trend. Therefore, in power plants, substations, underground railways, high-rise buildings and other places with a large number of electrical equipment and dense laying of a large number of cables, it is increasingly important to use fire-resistant cables to ensure uninterrupted power supply of important circuits. Fire-resistant cable



Fire-resistant power cable refers to the cable that can maintain a certain period of safe operation in the case of flame combustion.

According to the national standard GB12666.6 (such as IEC331), the fire test will be divided into A and B two levels, A flame temperature 950~1000℃, continuous fire time 90min, B flame temperature 750~800℃, continuous fire time 90min, the whole test period, the sample should withstand the rated voltage value specified in the product. Class A fire-resistant cable has better fire resistance than class B.

Fire-resistant wire and cable is fire-resistant test under the specified fire source and time, and has the ability to transmit power under the specified state, which can ensure the integrity of the line. Fire-resistant cable can maintain the normal operation of the line for a certain period of time, mainly used in fire conditions must also ensure the normal transmission of power important occasions.

The most common type of fire-resistant cable

NH-YJV cable: cross-linked polyethylene insulated polyvinyl chloride sheathed refractory power cable

WDZN-YJY cable: Copper core crosslinked polyethylene insulation low smoke halogen-free flame retardant polyolefin sheathed flame retardant fire retardant cable

Precautions for use

First, when the cable joint, the conductor and insulation between the use of four layers of mica tape overlapping wrap tightly as a refractory layer, other construction methods are consistent with similar products.

Second, the cable should strictly avoid sharp damage, otherwise it will reduce the fire resistance of the cable.

According to the specific characteristics of fire-resistant cables, designers should pay attention to the following problems when designing and selecting:

1) When fire-resistant power cables are used in cable dense cable tunnels, cable interlayers, or located in flammable places such as oil pipelines and oil depots, Class A fire-resistant cables should be selected first. In addition to the above cases and when the number of cable configurations is small, Class B fire-resistant cables can be used.

2) Fire-resistant cables are mostly used as the power supply circuit of emergency power supply, requiring normal operation in case of fire. Due to the sharp rise in the ambient temperature during the fire, in order to ensure the transmission capacity of the line and reduce the voltage drop, the section of the fire-resistant cable should be enlarged by at least one step for the circuit with a long power supply line and a strict limit on the allowable voltage drop.

3) Fire-resistant cables can not be used as high temperature resistant cables.

4) In order to reduce the failure probability of cable joints in fire accidents, the number of joints should be reduced as far as possible during installation to ensure that the line can work normally in a fire. If you need to do branch wiring, you should do a good fire treatment of the joint.

Qingdao Tianxing Cable Co., Ltd. is a technology enterprise specializing in the production of wire and cable in Shandong Province, with more than 150 sets of domestic excellent cable production equipment and testing equipment, excellent production technology, modern testing equipment, to ensure stable product quality and timely supply. The company's main products are power cable, mineral cable, high life wire and cable, radiation crosslinked cable, control cable, computer cable, photovoltaic cable, communication cable, data cable, low smoke halogen free cable, flame retardant series wire and cable.