Hi-Pot Test Voltage

Formula

Description

Hipot (high-potential) testing verifies the dielectric withstand capability of electrical insulation by applying a test voltage significantly higher than the normal working voltage. The standard formula of twice the working voltage plus 1000V comes from IEC 60950 / IEC 62368 safety standards for IT equipment. This test voltage is applied between primary and secondary circuits, or between live parts and accessible conductive parts, for 60 seconds during type testing. It detects insulation weaknesses, contamination, and insufficient creepage/clearance distances.

Variables

• V_test — Required hipot test voltage (V)
• V_working — Maximum normal operating voltage (V)

Practical Notes

Production line testing typically uses 80% of the type test voltage or applies the full voltage for shorter duration (1-2 seconds). For 240V mains equipment, the hipot test voltage is 2×240+1000 = 1480V, often rounded up to 1500V. Some standards use different formulas; always check the specific applicable standard (UL, IEC, EN) for your product category.