Which set of voltages is commonly used for insulation measurements with a hipot tester?

• A. 125, 250 or 500 volts
• B. 250, 500 or 1000 volts
• C. 100, 250 or 500 volts
• D. 300, 600 or 1200 volts

Answer: (B)

High-pot or hipot insulation testing uses a high voltage to stress the insulation between conductors and ground so any breakdown paths or excessive leakage show up.

The voltages chosen for this testing are standard because they cover a wide range of equipment ratings while leaving a safe margin above normal operating voltage. The commonly used set—250, 500, and 1000 volts—lets you test everything from lower-voltage devices to higher-voltage gear without needing unusual levels. This progression fits typical insulation classes and aligns with what many test standards and instruments provide as preset levels, making testing practical and the results comparable.

Other sets may either be too low for higher-rated insulation or include voltages that aren’t as commonly used in standard testing, which is why they aren’t as widely adopted.