Insulating Materials for Cables
- The insulating materials (dielectrics) used for cables must have low discharge current, low dissipation factor (low loss tangent), and should be chemically stable.
- The materials generally used are impregnated paper, bituminous compounds, rubber, compressed air, mineral oil etc.
- In the present days, cross-linked polyethylene cables (XLPE) are manufactured for 11 kV, 33 kV and 66 kV rating in comparison to paper insulated cable.
- They have the advantages of inherent moisture resistant, high flexibility, simple accessories, smaller size (with respect to paper or PVC cables).
- Liquids are used as impregnants for the insulation of solid type cables and as a filling for hollow core, liquid-cooled, and gas pressurized cables.
- The liquid acts as a dielectric and also as a coolant. The gas filled cables use sulfur hexafluoride as the gas.
Insulating materials for Electronic Equipment
For most of the electronic equipments, synthetic resins are used as insulants. For different
For different equipment the insulating materials used are:
|High power transmitters, industrial electronics, military, radar, ship.||Synthetic resins, glass, ceramics, paper, and oil.|
|TV and radio receivers||Synthetic resins, paper and press board|
|Medical electronics||Synthetic resin, paper, press board and oil.|
|Space electronics||Glass fabric, synthetic resins, and paper|
|Computers (the insulants must possess dimensional stability)||Synthetic resins and paper.|