The introduction of special wire cable

Special wire cable is a series of products with unique properties and special structure, the equivalent of ordinary wire and cable quantity bedding face is wide, with high technical content, use more strict conditions, the characteristics of small batch and high added value. Often using new materials, new structure and new technology and new design calculation.This kind of wire cable can be roughly divided into the following four categories.

A. High temperature resistant wire cable
Aerospace, vehicles, energy, steel, non-ferrous metal smelting, oil resistant to high temperature wire and cable, motor, etc. Long-term continuous working temperature of 125 degrees, 135 degrees, 150 degrees, 180 degrees, 200 degrees, 250 degrees and 250 degrees or more resistant to high temperature wire and cable, at present commonly used are radiation crosslinked polyolefin, silicone rubber, fluorine resin, polyimide, mica, magnesium wire and cable, etc.Are introduced; Two kinds of new type high temperature wire and cable, 1. Polyether sulfone insulated wire, 2. Polyether ether ketone insulated wire.
B. The purpose and structure of special wire cable
1. Low inductance cables
With heavy current and weak current, here introduces a kind of high voltage with low sense of cables. The electric cable with a heat dissipation device, used for all kinds of resistance welder, arc welder and pneumatic electrode holder connected between the new type of low water cooled cable, has simple and reasonable structure, large cooling water circulation, will not become blocked block and the limit of flow phenomenon, good heat dissipation effect, long service life, etc.
2. Low noise cable
In bending, vibration, shock, temperature change under the influence of external factors, such as pulse signals generated by the cable itself is less than 5 mv cable called low noise cable, also known as shock instrument cables. Used in industrial, medical, defense and other fields of tiny signal measurement.
C. Functional wires
1. The fluoride resin self-control steady 135 - degree heating cable
Its thermal process is different, show the conductive properties and stability of different level, this is because the matrix crystallization degree and crystal morphology is influenced by different cooling speed because of the insulation.
2. Electroluminescent wire
Electroluminescent wire is a latest product, in the field of international light-emitting display similar shape with ordinary wire and cable.
D. New type of green environmental protection wire and cable insulation
1. The CMP cable
Can pass ul flame retardant highest grade standard cable, for CMP cable. In general, is the base material of low smoke zero halogen polyolefin, it has higher fuel quantity of heat, is highly combustible, so they are mixed with filler metal hydrate, to curb its flammability, but the water of hydration, after running out can cause burning fiercely.
2. The halogen-free cable, new type of green environmental protection wires cables

Influence of insulation eccentricity to cables

For rubber plastic insulated power cable, due to the reason of the manufacturing process, its surrounding the conductor insulation thickness may not be equal, namely, insulation eccentricity.
In the structure of radial electric field H cable shielding layer on the surface of the conductor insulation layer is the end point of the electric field, when the insulation thickness, the electric field for coaxial cylinder electric field. The electric field of rubber cable insulation layer distribution is uniform, that is in the same radius of insulation on the circumference of a circle of electric field intensity are equal.
When the uneven thickness of insulation and eccentric, electric field is no longer a coaxial cylinder electric field, the electric field distribution within the insulation layer is not uniform, deterioration of the electric field will be concentrated in insulating thin place, where the insulation of the thinner of the electric field intensity. Visible, insulation eccentricity for the radial electric field of the structure of the H cable, it is very harmful, when serious can cause insulation breakdown.
The current cable in the national standard GB/T 12706, demand for cable insulation layer is:
(1) the insulation thickness shall be not less than 6 average nominal thickness.
(2) the minimum insulation thickness shall be not less than 90% of the nominal value -- 0.1mm.
(3) for more than 35kv voltage grade of cable, the eccentricity (maximum thickness) divided by the difference between the maximum and minimum thickness thickness should be not greater than 15%.
In low voltage cable, is using the radial electric field structure, namely each phase no shielding layer insulation surface, such as PVC cable, etc. This cable will not because of excessive deteriorating insulation eccentricity and electric field, the insulation thickness as long as the foot against the requirements of the former two.