What Are the Differences Between Mineral Insulated Cable and Flame Resistant Cable?

Ⅰ. The different meanings of mineral insulated cables and flame resistant cables

1. Mineral insulated cable

It is composed of inorganic materials, non-flammable, and does not produce harmful gases. When a fire occurs, smoke and poisonous gas are the most deadly. This is also one of the biggest advantages of mineral insulated cables. It can be used for a long time at 250°C, and can work continuously for 3 hours at 950-1000°C. The working temperature of mineral insulated cables can reach 105°C.

2. Fire resistive cable

It is composed of insulating material, low halogen, low smoke, and whether it extends flame or not is not included in the assessment. In the event of a fire, keep the operation for a certain period of time, that is, maintain the integrity of the circuit and have the power supply capacity for a certain period of time. The working temperature of fire-resistant cable can reach 90℃ under special conditions, and it can work continuously for half an hour at 950-1000℃.

Ⅱ. The difference in power supply capacity between mineral insulated cables and flame resistant cables

1. Mineral insulated cables

The interception capacity is larger than that of fire-resistant cables, which is equivalent to 1-3 intercepting surfaces less than that of fire-resistant cables. That is, the same current passes through, but the volume is reduced.

2. Flame resistant cables

The power supply capacity is still superior to traditional cables. Fire-resistant cables are mostly used as power supply circuits for emergency power supplies and require normal operation in the event of a fire. Because the ambient temperature rises sharply during a fire, in order to ensure the transmission capacity of the line and reduce the voltage drop, for circuits with long power supply lines and strictly limited allowable voltage drops, the cross-section of the fire-resistant cable should be enlarged by at least one level.

Ⅲ. Laying methods of mineral insulated cables and flame resistant cables

1. Mineral insulated cables

no maintenance or replacement is required for more than 50 years (BTTZ cable life is more than 100 years), and can be exposed or buried directly, saving the cost of cable trays. Mineral insulated cable is a cable in which copper conductor cores are wrapped with a copper sheath, and magnesium oxide powder is used as an inorganic insulating material to isolate the conductor and the sheath. The outermost layer can be appropriately selected as required. Commonly known as MICC or MI cable. There is a similar cable that uses metal instead of copper sheath to wrap the core wire and insulating material, which is called mineral insulated metal sheathed cable.

2. Flame resistant cables

It is easy to be aging and needs frequent maintenance and replacement after a period of use. Flame resistant cables refer to cables that can maintain safe operation for a certain period of time under flame burning. Fire-resistant cables are widely used in high-rise buildings, underground railways, underground streets, large power stations and important industrial and mining enterprises and other places related to fire safety and fire rescue, such as power supply lines and control lines of emergency facilities such as fire equipment and emergency guide lights.