With the increasingly stringent requirements for insulation safety in power equipment and industrial motors, AC Hipot testing has become an indispensable part of motor production, maintenance, and preventive maintenance. However, facing the dazzling array of voltage tester models on the market, how to scientifically and accurately select a suitable equipment for motors is a practical problem faced by many electrical engineers and procurement personnel. This article summarizes the key points of selection four dimensions: testing voltage, output capacity, safety characteristics, and application scenarios.

1、 Determine the test voltage: starting the rated voltage and following the standard

The first step in selecting an AC Hipot tester is to determine the required test voltage. This parameter is not set out of thin air, but based on the rated operating voltage, insulation level, and applicable safety standards of the motor.

The basic principle is to start the rated voltage of the equipment and then add the margin required by relevant safety standards or technical specifications. For low-voltage motors, many safety standards use calculation formulas that are linked to the operating voltage; The standards for power equipment are often set at a fixed testing level based on voltage levels.

2、 Calculating output capacity: an indispensable 'invisible' parameter

Many testers only focus on voltage, but overlook the capacity of the tester (kVA or VA) - this is the most easily underestimated key parameter in AC Hipot tester selection. When the AC hipot test is applied to the motor winding, the winding exhibits a capacitive load, and the resulting charging current may be considerable.

3、 AC vs DC: Why AC testing is preferred for motors

AC hipot testing and DC hipot testing each have their own applicable scenarios. AC testing applies a 50/60Hz power frequency voltage to the insulation, which can simultaneously apply stress to the insulation in both positive and negative polarities, exposing potential defects that may be hidden under DC testing. For inductive load equipment such as motors and transformers, AC testing can better simulate the electric field stress under actual operating conditions.

DC hipot testing is commonly used for capacitive equipment such as cables, or when product design makes AC testing unsuitable. For most motor application scenarios, AC hipot is the preferred choice.

4、 Security features, portability, and compliance

In addition to voltage and capacity, the following factors should also be considered when selecting:

Safety protection function: Priority should be given to testers with arc detection, emergency stop, remote control operation, overcurrent automatic power-off, and other functions.

Portability: For on-site testing and operation scenarios, lightweight, battery powered portable devices have more advantages.

Standard compliance: Ensure that the equipment complies with applicable standards such as IEC, IEEE, UL, etc. Motor testing should pay special attention to the IEC 60034 series and corresponding GB standards (such as GB/T 755).

Leakage current detection accuracy: Choosing equipment with real-time leakage current monitoring and threshold alarm functions can help accurately determine the insulation status.

Choosing an AC Hipot tester for a motor is not just about looking at the "highest voltage". The scientific selection path should be: first, clarify the test object and applicable standards, and determine the required test voltage; Estimate the winding capacitance based on the motor power and voltage level, and calculate the required output capacity; Finally, choose the appropriate safety configuration and portability based on the usage scenario (laboratory, production line, or on-site).