What is Cable Insulation and Type of Insulation?

My last post was about what are electrical cable and its type? Today I will discuss about cable insulation type. So let’s go.

First of all Cable Insulation:

The three most common available materials are used as insulation for any kind of power cable

  1. Tape insulation such as impregnated paper or varnish paper,
  2. Rubber or rubber like Synthetic compound such as Silicone rubber, butyl rubber and oil based rubber.
  3. Thermo-plastics such as Polyvinyl chloride (PVC) and Cross linked poly ethylene’s (XLPE).
XLPE Cable
XLPE Cable

Now come to the insulating materials and it should have the following properties

  1. High Resistivity
  2. High Dielectric strength
  3. High Tensile Strength and Plasticity
  4. Always low water Absorption Tendency.
  5. Non-inflammable
  6. Excellent Heat Exchange Capacity
  7. Chemically Stable (Free from any kind of hazardous gas)

Related: What is the Difference in AC Current and DC Current?

Cable Insulation Shielding:

Insulation shielding confines the dielectric field within the cable lo obtain symmetrical radial distribution of voltage stress. If the shielding are grounded. It reduces the hazards as ground protection. Due to code shielding, we can distinguish the phase easily

Cable Bending Types:

Normally bending tapes are used in a cable to add mechanical strength. They are located at various places by different manufacturer under the sheath, under the insulation or between the conductor and insulation material.

Cable Filler Type:

Suitable materials are used interstices of the cable as filler where necessary. The filler materials are hemp, rope, and synthetic rubber compound or thermo-plastic materials

Cable Jacket Covering:

It is the final or finishing stage of a power cable. The jackets or sheaths are used for insulation & mechanical protection. Sheaths are made from rubber, PVC, thermo-plastic etc.

If you found this post is helpful then please share with your friends and let them know about the electrical cable insulation specification. In my next post I will discuss about cable classification. See you soon.

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