___ surrounds the windings in typical 'pole-mounted' transformers.

___ surrounds the windings in typical 'pole-mounted' transformers.

• A. Air
• B. Oil
• C. Water
• D. Fiberglass

Answer: (B)

The windings in typical pole-mounted transformers are surrounded by transformer oil. This oil serves both as a dielectric insulator and a coolant. The oil fills the tank around the windings, preventing arcing between conductors and from windings to the tank, while also carrying heat away from the windings to the outer radiator and conservator so temperatures stay within safe limits. Air wouldn’t provide enough insulation or cooling, water would conduct electricity and cause faults, and fiberglass wouldn’t offer the necessary immersion insulation or heat transfer.

The windings in typical pole-mounted transformers are surrounded by transformer oil. This oil serves both as a dielectric insulator and a coolant. The oil fills the tank around the windings, preventing arcing between conductors and from windings to the tank, while also carrying heat away from the windings to the outer radiator and conservator so temperatures stay within safe limits. Air wouldn’t provide enough insulation or cooling, water would conduct electricity and cause faults, and fiberglass wouldn’t offer the necessary immersion insulation or heat transfer.