How to use a multimeter to test the quality of a three-phase water pump
1. Measure the resistance of the motor winding: first measure the resistance of the motor coil with the resistance gear of the multimeter. If it is a three-phase motor, measure the resistance of the three-phase coils separately. The resistance value is normal between tens of ohms and thousands of ohms, and the three sets of data of the three-phase motor are close to normal. The purpose of the measurement is to measure the quality of the motor winding coil, and to determine whether the coil is burnt, the short circuit between the motor slots, etc.
2. Measure the insulation of the motor winding to the ground: use the multimeter to measure the resistance of the motor coil and the casing at 10k gear. If it is a three-phase motor, the resistance of the three groups of coils and the casing should be measured separately. One end of the multimeter is connected to the coil outlet, the other end is connected to the motor shell, and the resistance value is above 1M ohms (minimum power is above 0.5M ohms), which is normal. The purpose of the measurement is to detect whether the insulation performance of the motor to the casing is good.
