We cannot live without electricity. Cables are essential energy transmission tools. If they make our lives easier, they can also represent a major safety risk. Electrical fires top the list of fire accidents, according to the latest statistics on the causes of fire accidents. This is why, in addition to common fire prevention measures for wires and cables, fire-resistant cables are increasingly being put forward.
Classification of Non-combustible Cables
The fire resistant cable is a cable with unique performance and special structure. It is flame retardant and fire resistant, resistant to high and low temperatures, low inductance and low noise, resistant to ants and rodents, waterproof and moisture resistant. Furthermore, it is environmentally friendly, does not emit smoke and does not contain halogen. There is no standardized international definition of a fire-resistant cable.
The cable industry is accustomed to flame-retardant cables, to refractory cables, non-combustible cables with mineral insulation and other cables with certain fire resistance performance, which are collectively called fire resistant cables.
Flame retardant cables are cables with specified flame retardant properties (For example, flame retardant characteristics, smoke density, smoke toxicity, corrosion resistance).The flame retardant performance means that the cable can be under the specified test conditions, combustion samples, in removing the ignition source, the flame spreads in the sample only within limits and goes out by itself.
Fire-resistant cables are cables with specified fire-resistant properties (For example, line integrity, smoke density, smoke toxicity, corrosion resistance). When the cable is burned under a specified fire source and duration (supply temperature of 750°C, feeding duration of 90 minutes), it can be operated continuously in the specified state and the line remains intact.
THE mineral insulated cables are cables made with a soft copper core, single or multiple, insulated by inorganic mineral tapes. Non-combustible mineral insulated cables are composed of a copper core, mineral insulation materials, copper and other metal sheaths. In cable testing, the selection of 950 ° C – 1000 °C flame burning mineral insulation class cable, it is still able to continue working in the specified state after burning 180min. It can also maintain line integrity. This type of cable has good incombustibility.
In case of fire, it is not necessary that the flame retardant cables can continue to function ; fire-resistant cables and mineral-insulated cables must be able to continue to operate ; mineral insulated cables have the highest fire resistance rating.
Advantages of Fire Resistant Cables
Flame retardant wires and cables have more advantages than ordinary cables.First of all, flame-retardant cables do not burn themselves and do not cause an ignition source. Even in the event of flame-burning, as long as the flame temperature is below the melting point of copper, the cable can continue to be used after the flame has gone out. It does not produce toxic fumes or gases if burned.
Secondly, flame retardant cables have a high operating temperature. The melting point of magnesium oxide crystal insulation is much higher than that of copper, so flame retardant cables can operate at temperatures up to 250°C and continue to operate at temperatures close to melting.
Thirdly, The flame retardant cable has strong overload protection. When the line is overloaded, the cable is not damaged until the heat reaches the melting point of the copper. Thirdly, even if decomposition occurs instantly, magnesium oxide crystals at the decomposition site will not form carbide. Once the overload is lifted, the performance of fire-resistant wires and cables does not change and they can continue to be used normally.
Fourth, The flame-retardant cable has good performance in anti-corrosion and explosion protection. Thanks to the use of seamless copper tubes as sheath, fire-resistant wires and cables resist water, humidity, oil and certain chemicals. Copper tubes have considerable mechanical strength and therefore good explosion-proof properties. Fifth, the lifespan of flame-retardant cables is longer than that of ordinary cables. Flame-retardant wires and cables are made of inorganic materials, there is therefore no phenomenon of aging of the insulation, the lifespan of ordinary cables can be increased by more than three times.
Finally, the installation of the fireproof cable is more flexible. Flame-retardant wires and cables can be laid on the deck with ordinary cables or special brackets, which is more flexible than ordinary cables. This also saves the investment in cable bridges and reduces the overall project cost. Flame-retardant cables significantly save labor and material resources.
the use of non-combustible cables
Fireproof cable is widely used in high-rise buildings, underground railways, the underground streets, large power plants and large industrial and mining companies, as well as in other places related to fire safety and rescue, such as hotels, banks, Hospitals, factories, commercial and residential integrated cabling, as well as power supply lines and control lines for fire-fighting equipment and emergency installations, such as emergency traffic lights.
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