Which test checks whether a cable can withstand a specified voltage for a specified duration?

• A. Dielectric Breakdown Test
• B. Insulation Resistance Test
• C. Continuity Test
• D. Dielectric Withstanding Test

Answer: (D)

The idea is to verify insulation endurance by applying a voltage higher than normal operating levels for a defined time and checking that leakage current stays within limits with no breakdown path. This dielectric withstanding test, also known as a hi-pot test, is designed to ensure the cable’s insulation can handle the voltage it might encounter in faults or transients without failing. It can use AC or DC voltage depending on standards.

This is different from an insulation resistance test, which simply measures how much leakage resistance exists at normal operating voltage to gauge insulation condition, not its ability to withstand a high voltage for a duration. It’s also distinct from a continuity test, which just checks that the conductor pathway is complete, and from a dielectric breakdown test, which seeks the voltage level at which insulation actually fails, often in a destructive characterization rather than a routine endurance check.