1. Conventional capacitor detection is divided into several steps.

(1) Visual measurement

Through intuitive observation, if the capacitor is found to be bulging and bursting, the capacitor needs to stop working and arrange for replacement as soon as possible.

(2) Record checking

The service life of capacitors is about 5 years. According to the replacement record, judge whether the capacitor needs to be replaced.

(3) Using tools for testing

If there is no obvious abnormality in visual inspection and the records are cluttered, it is necessary to use tools to detect capacitors.

Whether capacitor replacement or power-off detection, capacitors need to be discharged. After discharge, the capacitance of compensating capacitor is larger by using multimeter detection, so it needs to use the low-grade resistance to detect.

If the pointer of the multimeter does not move, it proves that there is a circuit break inside the capacitor; if the pointer of the multimeter all points to zero, it indicates that the capacitor is short-circuited; if the pointer swings left and right, the capacitor may leak electricity. If the pointer returns quickly, the faster the return speed, the better the capacitor.

If the capacitor needs to be tested under the condition of continuous electricity, the clamp ammeter can be used to detect the current in the wiring when the capacitor is working. Normally, the current gap of the conductor is very small, so the large current gap can also be used as a basis for judging the capacitance.