hipottesters

Hipotesters, short for high-potential testers, are instruments used to assess the dielectric strength of electrical insulation by applying a high voltage to a device under test (DUT) and measuring the resulting leakage current. They are commonly used in electronics manufacturing and quality assurance to verify insulation integrity in cables, power supplies, motors, transformers, medical devices, and consumer electronics.

Most hipotesters deliver either direct current (DC) or alternating current (AC) voltage. DC hipot testers apply a high voltage, typically ranging from hundreds of volts to several kilovolts, with the voltage often ramped or stepped. AC hipot testers apply 50/60 Hz voltage. The tester senses leakage current and compares it to predefined limits to determine pass or fail. Advanced models may also perform insulation-resistance measurements, polarization index testing, or partial-discharge detection.

During testing, the DUT is connected between the high-voltage terminal and a measurement return. A current limiter protects the DUT and the tester. Tests last from a fraction of a second to several seconds, after which the high voltage is discharged safely. Many testers include safety interlocks, shields, and remote sensing to reduce risk.

Typical specifications include voltage range, leakage-current limit (often microamps to milliamps), test duration, and automation features such as data logging and reporting. Hypot testing is designed to be non-destructive within specified limits; exceeding those limits can cause insulation breakdown and damage the DUT.

Regulatory standards and product requirements govern dielectric-withstand testing, with voltages and acceptance criteria varying by industry and region. Hipot testing is one element of a broader quality-control program for electrical insulation.