Method for Measuring Voltage Value of Capacitors

If it is necessary to test the voltage resistance of newly purchased capacitors or domestic fans, blower and other capacitors for starting single-phase motor, the insulation resistance meter and DC voltmeter can be used to measure the voltage. The principle is that the DC generator starts to work when the handle of the insulation resistive meter is shaken. For an insulating resistance meter with a rated voltage of 500V, when the hand rotation speed reaches 120 revolutions per minute, it should output a 500V DC voltage, which is not harmful to the capacitor because the output current is very small.

The operation method is as follows: first, the DC voltmeter (or the DC voltage file of the multimeter) and the capacitor to be tested are connected to the two end buttons of the insulation resistance meter, after which the handle of the insulation resistance meter is shaken slowly and quickly, and the indicator value of the voltmeter is inspected. If the pointer is no longer rising or rising and decreasing, then the maximum voltage of the capacitor is measured, and it is also the critical value of hollowing. In the work, we can also use 1000V insulation resistance meter or 2500V insulation resistance meter and the corresponding DC voltmeter to test the capacitor with high voltage value.

It should be noted that the capacitor should be treated with discharge after connection and test, and the positive and negative polarity of the insulation resistance meter should be judged well when the DC voltmeter is connected.