SOLUTION

Class A:

• Organic materials like cotton, silk, and paper when impregnated or immersed in oil.
• Enameled wire with enamel coating.
• Maximum operating temperature: 105°C (221°F).

Class B:

• Inorganic materials like mica, glass fiber, and asbestos (nowadays rarely used due to health concerns).
• May include organic binding substances in built-up form.
• Maximum operating temperature: 130°C (266°F).

Class E:

• Class E serves as an intermediate category between classes A and B.
• May include materials with slightly higher temperature ratings than Class A but not exceeding Class B.

Class F:

• Insulation based on mica, asbestos (rarely used), or glass fiber.
• Binding materials are high-temperature resistant, such as silicone.
• Maximum operating temperature: 155°C (311°F).

Class H:

• Similar to Class F but with even higher temperature resistance.
• Maximum operating temperature: 180°C (356°F).