What is a Mineral insulated cable? Why use Mineral insulated cable?
Source:VGCABLE Time:2020-03-04 20:19:59Click:122
Mineral insulation Cable: referred to as MI Cable, and used as wiring, also called Mineral Cable or Mineral fire-proof Cable.
1. Meaning of mineral insulated cable
Mineral insulated cable, also known as fireproof cable, is mainly used in high-rise buildings and special places or equipment to use the cable. The normal working temperature of mineral insulated cable is 250°C, and it will maintain a normal power supply of 950°C for three hours under the condition of combustion, providing more time for life and property safety and reducing the loss and injury caused by fire.
2. Composition of mineral insulated cable
Composition: mineral insulated cable is made of copper, minerals of insulation materials, such as copper metal sheath, in addition to with good electrical conductivity, mechanical and physical properties of refractory performance, also have good incombustible, this kind of cable in the case of a fire can not only ensure fire fire power supply in time, also won't delay, do not produce toxic fumes.
3. Classification of mineral insulated cables
At present, according to the structure can be divided into rigid and flexible two.
Represents the models BTTZ and YTTW.
a. BTTZ mineral insulated cable structure
BTTZ mineral cable structure
b. YTTW mineral insulated cable structure
YTTW mineral insulated cable structure
4. Advantages of mineral insulated cable
a. Fire resistance: copper and mineral insulation are inorganic materials used in mineral insulated cables. This kind of cable will not burn, also will not aid the combustion, in the condition that is close to the flame still can continue to operate. The copper sheath is melted at 1083℃.
b. High operating temperature: the continuous operating temperature of mineral insulated cable is up to 250℃. Moreover, in case of emergency, the cable can be operated for a short time at a temperature close to the melting point of the copper sheath.
c. Long service life: the inorganic material used in mineral insulated cable can ensure the stability, long service life and fire resistance of the cable.
d. Explosion-proof: highly compacting insulating material in mineral insulated cable, which can prevent steam, gas and flame from passing between the equipment parts connected with the cable.
e. Small outer diameter: the diameter of mineral insulated cable is smaller than that of other cables with the same rated current.
f. waterproof: if the mineral insulated cable is completely immersed in water, with the help of its seamless metal sheath, the mineral insulated cable can continue to operate.
5.Must fire cables be made of mineral insulation?
a. Fire protection code for building design gb50016-2014 1. Article 3: fire distribution lines should be laid separately from other distribution lines in different cable Wells and ditches; If it is really difficult to lay in the same cable well or trench, it should be arranged on both sides of the cable well or trench, and the fire distribution line should use mineral insulated non-combustible cable.
b. Limited by the area of the low-voltage distribution room, at present, the cable trench in the low-voltage distribution room is almost the cable trench Shared by the fire fighting and non-fire fighting cables. Because of this, the fire fighting lines in the cable trench in the distribution room cannot be completely isolated from the non-fire fighting lines, so the fire fighting cables need to use mineral insulated cables.
c. if the fire control cable to use fire-resistant cable to save costs, so must ensure that the transformer in low pressure for tank fire power cabinet and the fire power is completely separated from the ark, and for the fire line separate Settings in cable trench, the ground fire control cable and the fire control cable should be set up in two different electric Wells, or fire cable, all steel tube wear dark ensure fire line from low voltage transformer room to terminal equipment, fire dedicated line installation.