There are three factors:
1. Long-term allowable working temperature of cables.
2. Heat dissipation performance of the cable itself.
3. Cable installation and heat dissipation conditions of the surrounding environment.
Extended information:
Flame-retardant rubber-sheathed cable
I. Uses
This product is a series of rubber-sheathed flexible cables for mining. Suitable for power connection of shearer and similar equipment with rated voltage Uo/U of 1.9/3.3KV and below. Mostly used in coal mines.
II. Conditions of use
The long-term allowable working temperature of the core is 65℃, and the minimum bending radius of the wire is 6 times of the cable diameter. Yellow sheathed cable shall not be exposed to sunlight for a long time.
nuclear-grade cable
scope of application
1. This product is suitable for control and signal connection cables used in the control system network of nuclear power plant with the rated voltage Uo/U of .6/1kV.
2. The allowable long-term working temperature of the cable conductor is 9℃, and the maximum temperature of the cable conductor during short circuit shall not exceed 25℃ and the duration shall not exceed 5 seconds.
3. When laying cables, the ambient temperature should not be lower than ℃.
4. When laying cables, the allowable bending radius is:
For unarmored cables, it should not be less than 6 times the cable diameter.
cables with armored or copper tape shielding results should be no less than 12 times the cable diameter.
the flexible cable with shielding structure should be no less than 6 times the diameter of the cable.
5. When the long-term allowable working temperature of the conductor is not more than 9℃, the qualification life of the cable is not less than 4 years.
6. The finished cable shall meet the requirements of Class A bundled combustion test specified in GB/T1838.3 standard.
7. smoke density of finished cable: light transmittance is not less than 7%.
8. Radiation resistance: 25×14Gy
9. Halogen-free: When nonmetallic materials are burned, the acidity (expressed as PH value) of the escaping gas should be greater than 4.3, and the conductivity should not be greater than 1μ s/mm.
bare wires and bare conductor products
the main features of this kind of products are: pure conductor metal, without insulation and sheath, such as steel-core aluminum stranded wire, copper-aluminum bus bar, electric locomotive wire, etc.
The processing technology is mainly pressure processing, such as melting, calendering, drawing, twisting/compression twisting, etc. Products are mainly used in suburbs, rural areas, main lines of users, switch cabinets and so on.
power cable
products are mainly used for the transmission of high-voltage electric energy in power generation, distribution, transmission, transformation and power supply lines, with large current (tens of amperes to thousands of amperes) and high voltage (22V to 5kV and above).
Communication cables and optical fibers
With the rapid development of the communication industry in recent twenty years, the products have also developed at an amazing speed. From simple telephone and telegraph cables in the past to thousands of pairs of telephone cables, coaxial cables, optical cables, data cables and even combined communication cables.
this kind of products are usually small and uniform in structural dimensions, and require high manufacturing accuracy.
electromagnetic wire (winding wire)
is mainly used in various motors, instruments and meters.
the flexible fireproof cable
1. The fireproof performance is excellent. The fireproof grade not only meets the requirements of international GB12666.6A class at 95℃ for 95℃ 9min, but also meets the requirements of A class at 65℃ 3h B class at 75℃ 33C class at 95℃ 3h specified in British BS6387-1994. At the same time, it can withstand water jet and mechanical impact during combustion.
2. The continuous length is long. Whether it is a single-core or multi-core cable, its length can meet the needs of power supply length, and the ultimate length can reach 2m m.
3. The cross-section of single-core cable with large cross-section can reach 1mm2, and the cross-section of multi-core cable can reach 24mm2.
4. It is flexible, and the cable can be coiled on the cable reel, with the bending radius ≥2D, and d is the cable outer diameter.
5. It is smokeless and non-toxic when burning, and the insulation is made of inorganic material "non-combustible", which will not produce any harmful gas during burning, and will not cause secondary pollution, so it can be called an environmental protection and green product.
6. The cross-sectional capacity is too large, and the cable not only has a large cross-sectional flow, but also has a large overload capacity. According to the wiring requirements, the cable surface temperature is usually ≤7℃. If the wiring is untouchable and not in contact with combustible building materials, the temperature of cable sheath can reach 15℃. The allowable working temperature of the fire cable can reach 25℃ when it is overloaded.
7, corrosion resistance, organic insulated fire-resistant cables sometimes need to wear plastic pipes or iron pipes, plastic is easy to age and become brittle, and iron pipes are easy to rust. Fire-proof cable is copper sheathed, which does not need to be penetrated, and the copper sheathed has good corrosion resistance.
8. There is no electromagnetic interference. When the fire cable is laid in the same shaft as the signal and control wires and cables, the fire cable will not interfere with the information transmitted by the signal and control wires and cables under the shielding of copper sheath.
9. The safety is good. Besides normal power supply in the flame, the fire-fighting cable starts the fire-fighting equipment to reduce the fire loss. At the same time, it is particularly reliable for personal safety. Its copper sheath is a good conductor and the best grounding wire, and it is continuous to the whole length of the cable, which greatly improves the sensitivity and reliability of grounding protection.
1, long service life, inorganic insulating material, high temperature resistance, and not easy to age, its life is many times longer than that of organic insulated cables, and its life can be equivalent to that of buildings under normal working conditions.
11. The transportation and installation of flexible fire-proof cable includes installation
This part of cable is AC load cable, which is laid indoors and can be selected according to the requirements of general power cable selection.
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