Question

Insulation breakdown may occur at which temperature?

• A. High temperature
• B. Low temperature
• C. Depends on pressure
• D. At any temperature

Answer 1

Answer: (A)

High temperature

Answer 2

Insulation breakdown refers to the loss of insulating properties of a material, leading to it becoming conductive. This phenomenon is strongly influenced by temperature.

• High Temperature: As temperature increases, the kinetic energy of electrons and ions within the insulating material increases. This can lead to:

  1. Increased charge carrier generation: More electrons can gain enough energy to break free from their atoms, becoming conduction electrons.
  2. Increased charge carrier mobility: Free charge carriers move more easily through the material.
  3. Thermal degradation: Many insulating materials (especially polymers) degrade chemically and physically at high temperatures, losing their structural integrity and dielectric strength. This can lead to carbonization, melting, or softening, creating conductive paths.
  4. Reduced dielectric strength: The ability of an insulator to withstand an electric field without breaking down decreases significantly with increasing temperature.

• Low Temperature: Generally, low temperatures tend to improve the insulating properties of most materials by reducing the kinetic energy of charge carriers and increasing their resistance to movement. While extremely low temperatures can cause embrittlement, electrical breakdown due to temperature itself is primarily associated with high temperatures.

Therefore, insulation breakdown is more likely to occur or be initiated at high temperatures.