NOYAFA Electronic specializing in testing instruments and cable testers for 16 years
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NOYAFA Electronic specializing in testing instruments and cable testers for 16 years
Author: Noyafa–Cable Length Tester
Some electrical designers, because they cannot clearly distinguish the concepts of flame-retardant cables and fire-resistant cables, do not know much about their structure and characteristics, so they cannot correctly design and select these two cables according to the power supply requirements. Some electrical designers, because they cannot clearly distinguish the concept of flame-retardant cables and fire-resistant cables, do not know much about their structure and characteristics, so they cannot correctly design and select these two cables according to the power supply requirements. When designing agents or on-site supervision The laying and construction of these two kinds of cables cannot be properly guided. Today, the cable fault tester manufacturer will introduce the difference between flame-retardant cables and fire-resistant cables. Flame retardant cable refers to: under the specified test conditions, the sample is burned, after the test fire source is removed, the spread of the flame is only within a limited range, and the residual flame or residual burning can be extinguished within a limited time.
Its fundamental characteristic is: in the event of fire, it may be burnt out and cannot operate, but it can prevent the spread of fire. In layman's terms, in the event of a fire in the cable, the combustion can be limited to a local area without spreading, and other equipment can be protected to avoid greater losses. The structure of the flame-retardant cable is basically the same as that of the ordinary cable, the difference is that its insulation layer, sheath, outer sheath and auxiliary materials (taping and filling) are all or partially made of flame-retardant materials.
Fire-resistant cable refers to: under the specified test conditions, the sample is burned in the flame, and it can still maintain the performance of normal operation 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 burning conditions. In layman's terms, in case of fire, the cable will not burn at once, and the circuit is relatively safe.
The structure of the fire-resistant cable is basically the same as that of the ordinary cable. The difference is that the conductor of the fire-resistant cable adopts a copper conductor with good fire resistance (the melting point of copper is 1083°C), and a fire-resistant layer is added between the conductor and the insulating layer. The refractory layer is wrapped by multiple layers of mica tapes. Because the allowable working temperature of different mica tapes varies greatly, the key to the fire resistance of the cable is the mica tape.
Therefore, the main difference between fire-resistant cables and flame-retardant cables is that fire-resistant cables can maintain normal power supply for a period of time when a fire occurs, while flame-retardant cables do not have this feature. This characteristic determines that fire-resistant cables play an important role in modern urban and industrial buildings. The manufacturer of the cable fault tester pointed out that once a fire occurs, the power supply circuit of the control, monitoring, guidance and alarm systems must maintain normal operation.
Therefore, the cable is mainly used in the power supply circuit from the emergency power supply to the user's fire fighting equipment, fire alarm equipment, ventilation and smoke exhaust equipment, guide lights, emergency power sockets, and emergency elevators. The above is the analysis and introduction of the difference between the flame-retardant cable and the fire-resistant cable by the cable fault tester manufacturer. I hope it can help everyone.
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