How to judge the quality of insulation of low-voltage motors?

    The insulation condition of low-voltage motors below (500) volts is generally checked with a 500-volt insulation megger. If there is no insulation tester and the insulation condition of the motor needs to be determined quickly, a signal light can be used for a rough judgment.

    Judgment method:

    Connect a 220V signal lamp according to the diagram, then power it on and make the following judgments:

    1. If the light bulb is off, it means the insulation of the motor is good and can be put into operation;

    2. If the filament of the bulb turns red, it means there is leakage and the insulation of the motor is slightly damaged. If the production cannot be interrupted and the protection device is sensitive and reliable, the motor can be used temporarily;

    3. If the light bulb glows normally or very brightly, it means that the insulation of the motor is seriously damaged and cannot be used. Otherwise, a short circuit and burnout accident may occur.

    Similarly, the dotted line indicates that the insulation of the cable can be checked.