The difference between fire-resistant cable and flame-retardant cable

1. Fire-resistant cable

Based on improving the manufacturing process of the fire-resistant layer and adding fire-resistant layers, Class A fire-resistant cable was developed. It can withstand burning for at least 90 minutes in a flame of 950℃~1000℃ and rated voltage without the cable being broken down (that is, the 3A fuse does not blow).

2. Flame retardant cable

Flame retardant cable is one of the fire-resistant cables with better performance. It is made of copper core, copper sheath and magnesium oxide insulation material, referred to as MI (minerlinsulated cables) cable.

The fire-resistant layer of this cable is completely composed of inorganic substances, while the fire-resistant layer of ordinary fire-resistant cables is composed of a composite of inorganic substances and general organic substances. Therefore, the fire-resistant performance of MI cable is better than that of ordinary fire-resistant cables and it will not decompose and produce corrosive gases due to combustion.

MI cable has good fire resistance and can work at high temperature of 250℃ for a long time. It is also explosion-proof, corrosion-resistant, has large current carrying capacity, radiation resistance, high mechanical strength, small size, light weight, long life and smokeless.

However, it is expensive, the process is complicated and the construction is difficult. This type of cable with good fire resistant performance can be used in oil filling areas, important wooden public buildings, high temperature places and other places where the fire resistance requirements are high and the economy is acceptable.

Note: Fire-resistant cables can maintain normal power supply for a period of time when a fire occurs, but flame-retardant cables do not have this feature.

3. Issues that should be paid attention to when designing and applying

1. When fire-resistant cables are used in cable tunnels and cable interlayers with dense cables, or in flammable places such as near oil pipelines and oil depots, Class A fire-resistant cables should be used first. Except for the above situations 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 are required to work normally during fires. Since the ambient temperature rises sharply during fires, in order to ensure the transmission capacity of the line and reduce the voltage drop, the cross-section of the fire-resistant cable should be enlarged by at least one level for circuits with long power supply lines and strictly limited allowable voltage drops.
3. Fire-resistant cables cannot be used as high-temperature resistant cables.
4. In order to reduce the failure rate of cable joints in fire accidents, the number of joints should be minimized during installation to ensure that the line can work normally during fires. If branch wiring is required, the joints should be properly fireproofed.