1. What is the meaning of the flame retardant wire?
The meaning of flame retardant: under the specified test conditions, the sample is burned. After the fire source is removed, the spread of the flame on the sample is only within a limited range and self-extinguishing, that is, it has the function of preventing or delaying the occurrence or spread of flame. ability.
The burning of the cable is caused by external heating to produce a flammable gas. To achieve the purpose of flame retardation, it is necessary to suppress the three factors that cause combustion, namely: combustible gas, heat and oxygen. Therefore, the flame-retardant wire and cable cable generally adopts a method of adding a halogen-containing halide and a metal oxide to the sheath material, which is an excellent method from the viewpoint of flame retardancy, but since these materials contain halogenation The substance releases a large amount of smoke and hydrogen halide gas when it is burned. Therefore, the visibility in the fire is low, which causes great obstacles to the safe evacuation of personnel and fire, and people are more likely to suffocate to toxic gases.
In addition, once the hydrogen halide gas reacts with the water in the air, it generates "hydrogen halide acid", which seriously corrodes the equipment and buildings and causes "secondary disasters."
At present, with the continuous improvement of the level of technology, the flame retardant problem has been flame retarded by the past halogen, and further developed to low-halogen, halogen-free flame retardant.
The wire and cable representation method is mainly composed of three parts: model, specification and standard number. 1. Meaning of the model The type of the cable and power cable for electrical equipment is mainly composed of the following seven parts: Some special wire and cable models have a derivative code at the end. The following describes the meanings of the letters in the most common wire and cable models: 1) Category, use code A-installation line B-insulated wire C-ship cable K-control cable N-agricultural cable R- cord U-mine cable Y -Mobile cable JK-insulated overhead cable M-ZR-flame-retardant NH-refractory type ZA-A flame retardant ZB-B grade flame retardant ZC-C grade flame retardant WD-low smoke zero halogen type.
Second, what is the difference between cable models ZA, ZB and ZR?
ZR is the meaning of flame retardant. Flame retardant is divided into three grades of A, B and C. ZB represents B grade flame retardant. ZR defaults to grade C flame retardant.
Flame retardant properties ZA > ZB > ZC.
沪公网安备31012002003149号
