The insulation layer of the power cable is composed of various combustible materials such as paper, oil, hemp, rubber, plastic, and asphalt. Therefore, the cable has the possibility of fire and explosion. The cause of the cable explosion is:
(1) Insulation damage causes a short-circuit fault. The protection of the power cable is damaged during laying or lead to mechanical damage to the cable insulation during operation, causing insulation breakdown between cables or between lead sheets. The resulting arc causes the insulating material and the outer protective layer of the cable to ignite and catch fire.
(2) The cable is overloaded for a long time. For a long period of overload operation, the operating temperature of the cable insulation material exceeds the maximum allowable temperature for normal heating, so that the insulation of the cable is aged and dried. This phenomenon of insulation aging and dryness usually occurs on the entire cable line. As the cable insulation is aged and dry, the insulating material loses or reduces the insulation performance and the mechanical performance, so that it is easy to strike fire and burn even at the same time along the entire length of the cable.
(3) The oil-immersed cable is damaged or leaks due to height difference. When the height difference of the oil-immersed cable laying is large, the phenomenon of oil slick in the cable may occur. As a result of the turbulent flow, the upper part of the cable is dried up due to the loss of oil. This part of the cable has increased thermal resistance, causing coking of the paper insulation and premature breakdown. In addition, since the upper portion of the oil squats downward, a space is created at the upper cable head and a negative pressure is generated, so that the cable can easily absorb moisture and make the end portion wet. The lower part of the cable generates a large static pressure due to the accumulation of oil, causing the cable head to leak oil. Cable moisture and oil leaks increase the chance of a fire.
(4) Insulation breakdown of the middle connector box. The middle joint of the cable splice box is not tightly pressed, the welding is not firm or the joint material is not properly selected. During operation, the joint is oxidized, generates heat, and flows. When the cable middle joint is made, the quality of the insulating agent poured in the middle joint box does not meet the requirements. Requirements, when the insulating agent is poured, there are pores in the box and the cable box is poorly sealed, damaged and leaks moisture. All of the above factors can cause insulation breakdown and short circuit, causing the cable to explode and catch fire. Electrical automation technology (5) Cable end combustion. As the surface of the cable head is damped and accumulated, the porcelain casing of the cable head is broken and the distance between the lead wires is too small, causing the flashover to ignite and causing insulation on the surface of the cable head and insulation burning of the lead wire.
(6) External fire and heat sources cause cable fires. Such as the spread of fire in the oil system, the spread of oil circuit breaker explosion fires, the spontaneous combustion of coal powder in coal-fired boiler systems or coal-fired systems, the baking of high-temperature steam pipes, the chemical corrosion of acids and alkalis, the welding sparks, and other types of fire, all of which can make cables Fire.
The company solemnly declares:
1, signed a product quality assurance book, promise - never failed to leave the factory.
2. Two years of product quality tracking service, and record customer service records for 20 years.
3, indeed due to product quality problems, our company will warranty, return, replacement, to meet customer requirements.
Specifications: Customized according to customer's requirements Number of products: MOQ is 100 meters, 100 meters to 200 meters Price Float Packing Description: Shorter discs with a few meters, long cable lengths
We are mainly produce magnetic components in Permanent Magnet Motor field, especially NdFeB permanent magnet motor accessories which can match all kinds of medium and small permanent magnet motor. The rare-earth permanent magnet motor can not only achieve high performance (such as high efficiency, special high speed, special high response speed) which the traditional electric excitation motor can't compare, but also can be made into special motor which can meet the requirements of specific operation, such as elevator traction motor, automobile special motor and so on.
Features: 0.01 concentricity can meet up to 200k RPM
Magnet Rotor Assembly,Permanent Magnet Generator,Permanent Magnet Motor,Permanent Magnet Rotor
Chongqing Great Well Magnet Co.,ltd. , https://www.gwmagnet.com