Regarding fire-resistant cables and flame-retardant cables, it is basically the same in everyone's perception. In fact, there are still many differences between the two. Here are some of the differences between Henan Wanjia Cable Finishing. To understand the difference between the two, first understand what is a fire resistant cable and what is a flame retardant cable.
What is a fire resistant cable?
Fire-resistant cables are classified into Class A and Class B. Class A fire-resistant cables have better fire resistance than Class B.
Class B cables are capable of withstanding combustion for at least 90 minutes in a flame at 750 ° C to 800 ° C and rated voltage without the cable being broken down (ie, the 3 A fuse is not blown).
Based on the improvement of the refractory layer manufacturing process and the increase of the refractory layer, a Class A fire-resistant cable was developed, which can withstand combustion for at least 90 min in the flame at 950 ° C to 1000 ° C and the rated voltage without the cable being broken down ( That is, the 3A fuse does not blow).
What is a flame retardant cable?
Flame-retardant cable is a kind of excellent performance in fire-resistant cable. It is made of copper core, copper sheath and magnesium oxide insulating material, referred to as MI (minerlinsulatedcables) cable.
The cable is composed entirely of inorganic materials, and the refractory layer of the ordinary fire-resistant cable is made of inorganic materials and common organic materials. Therefore, the fire resistance of the MI cable is superior to that of the ordinary fire-resistant cable and does not decompose and burn due to combustion. gas.
MI cable has good fire resistance and can work under high temperature of 250 °C for a long time. It also has explosion-proof, strong corrosion resistance, large current capacity, radiation resistance, high mechanical strength, small volume, light weight, long life and smokeless. specialty.
However, the price is expensive, the process is complicated, and the construction is difficult. In the oil irrigated area, the important wooden structure public building, the high temperature place and the like, the fire resistance is high and the economy is acceptable, and the cable with good fire resistance can be used.
The differences between fire resistant cables and flame retardant cables are as follows:
Fire-resistant cables can maintain normal power supply for a period of time in the event of a fire, and flame-retardant cables do not have this feature.
The following issues should be noted when designing an application:
When fire-resistant cables are used in cable-dense cable tunnels, cable interlayers, or in flammable locations such as oil pipes or oil depots, Class A fire-resistant cables should be used first. In addition to the above, and the number of cable configurations is small, Class B fire-resistant cables can be used.
Fire-resistant cables are mostly used as power supply circuits for emergency power supplies and require normal operation in case of fire. Due to the sharp rise of the ambient temperature during the fire, in order to ensure the transmission capacity of the line and reduce the pressure drop, the cross section of the fire resistant cable should be at least one step for the circuit with a long supply line and strict limits on the allowable voltage drop. Recommended products: control cable
Fire resistant cables cannot be used as high temperature resistant cables.
In order to reduce the probability of failure of the cable joint in a fire accident, the number of joints should be minimized during installation to ensure that the line can work normally in a fire. If branch wiring is required, the joint should be fireproofed.