18 Different types of Electrical Insulating Materials | Insulation Class

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For electrical and electronic system protection, electrical insulation plays the most important role as a protector.

Especially, for an electrical conductor, grounded system, electrical machines like a transformer, motor, and generator, and other electric appliances; insulation is provided for safety purposes.

There are different types of electrical insulation which are made of different types of insulating materials.

Let’s study, what are the different types of electrical insulating materials used for insulation.

Types of Electrical Insulating Materials

Insulating materials can be found in different states like solid, liquid and gaseous.

  1. Paper
  2. Cotton or Silk
  3. Plastic (Sheet or Tube)
  4. Glass
  5. Ceramic
  6. Mica (or Micanite)
  7. Wood (like Permali type)
  8. Air (Use as an Insulator)
  9. Oil (Mineral type)
  10. Polyvinyl Chloride (PVC)
  11. Rubbers (Natural and Synthetic type)
  12. Varnish (Insulating Liquid Coating)
  13. Gel or Wax (Collinite Insulator Wax)
  14. Fiberglass (Sheet or Sleeves or Cloth)
  15. Presspahn Paper or Leatheroid Paper
  16. Kapton (Tape or Wire)
  17. Resins or Polymers (Polyester and Polyurethane Resins)
  18. Moulded Bakelite (Use for Terminal Plates)

Insulating materials are used or required for safety purposes against electrical hazard conditions. They are easily available in the market.

In an overhead power system, insulators work as a protector which is made by insulating materials like ceramic, glass, and porcelain.

Read more: 6 different Insulator types with specification, properties and uses.

Which Insulation is used in an Electrical Machine?

Let’s talk about Electrical Machine and insulators.

  • Paper and Varnish are widely used for electrical machine winding and slot.
  • Oil and Air insulating materials are used in electrical transformers, regulators, and circuit breakers where it helps to dissipate the generated heat.

7 Different Types of Insulation Classes

What are Different Types of Insulation Classes?

Insulation depends on thermal (temperature) or heat energy. Based on temperature or heat, insulating materials are mainly classified into seven classes.

#ClassTemperatureInsulating Materials
01Class A105°CImpregnated paper, silk, cotton, coated or immersed in a dielectric liquid such as oil.
02Class B130°CMica, Fibre, Glass, Asbestos (Inorganic material) with suitable bonding, impregnating, or coating substances.
03Class CAbove 180°CMica, Porcelain, Ceramics, Glass, Quartz, etc. with or without bonding, impregnating, or coating substances.
04Class E120°CSynthetic Resins, Enamel wires, Cellulose, etc.
05Class F155°CMica, Glass, Fibre, Asbestos, etc., with a suitable coating, bonding, impregnating as well as combinations of materials.
06Class H180°CCombinations of materials of mica, fiber, glass, asbestos, etc
with suitable bonding or impregnating or coating and Silicone Elastomer.
07Class Y90°CCotton, silk, wood, paper, cellulose, and similar organic materials without impregnated.

Above these seven insulation classes have the ability to handle a range of heat energy.

If you have any query regarding insulation or different types of electrical insulating materials, you can ask me below by commenting.

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10 thoughts on “18 Different types of Electrical Insulating Materials | Insulation Class”

  1. Thanks, Dipali for sharing such a useful post, I´ve found it on the Internet, and I really appreciated your article.


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