What are the two standard tests to assess insulator dielectric strength?

• A. Dry-withstand voltage test
• B. Wet-withstand voltage test
• C. Insulation resistance test
• D. Partial discharge test

Answer: (A)

Dielectric strength is about how well an insulator can resist breakdown under high voltage. To measure this, standards use withstand voltage tests under two conditions: dry and wet. The dry-withstand voltage test checks the insulator’s ability to withstand high voltage when it is dry, establishing the baseline dielectric strength. The wet-withstand voltage test then simulates moisture or contamination to see if dielectric strength holds up in harsher, more realistic conditions. The option chosen reflects one of these standard tests, recognizing that the wet version is the complementary test. Other tests like insulation resistance or partial discharge assess different electrical properties, not the basic dielectric-strength withstand tests.