Method of testing capacitor withstand voltage

Any capacitor must be subjected to a withstand voltage test and other electrical performance tests before use, so as to ensure that the accuracy of the capacitor meets the specification requirements, thereby ensuring the safety and reliability of the product. These tests are so important, so follow in the footsteps of the editor to take a look at the method of testing the capacitor withstand voltage!


If you need to test the withstand voltage of newly purchased capacitors or household electric fans, blowers and other capacitors used for starting single-phase motors, you can use an insulation resistance meter and a DC voltmeter to measure. Its principle is that when the handle of the insulation resistance meter is shaken, the DC generator starts to work. For an insulation resistance meter with a rated voltage of 500V, when the hand crank speed reaches 120 revolutions per minute, it should output a DC voltage of 500V, because its output current is very small, so there is no damage to the capacitor.
The operation method is as follows: First, connect the DC voltmeter (or the DC voltage file of a multimeter) and the capacitor under test in parallel to the two terminals of the insulation resistance meter. After connection, slowly accelerate the handle of the insulation resistance meter to check the indication value of the voltmeter. If the pointer no longer rises or rises and then falls, what is measured at this time is the withstand voltage value of the capacitor, and it is also its critical null value. In work, a 1000V insulation resistance meter or a 2500V insulation resistance meter and a corresponding DC voltmeter can also be used to test capacitors with higher withstand voltage.


It should be noted that the capacitor must be discharged after wiring and testing, and the positive and negative polarity of the insulation resistance meter must be judged when connecting the DC voltmeter. The above is the withstand voltage test method of the capacitor, I hope it can help you. We must not neglect the test before use, it is very important to do every step well.