How to Judge the Quality of Capacitor for Refrigeration Compressor?

2024-10-07

The capacitor of the refrigeration compressor enables the motor to start and run by phase-shifting the single-phase current. The motor of the single-phase power supply fixed-frequency air conditioning compressor uses a single-phase asynchronous motor. According to the working principle of this kind of motor, it is necessary to achieve a phase difference in the currents of the two sets of motor windings, otherwise it cannot start.

When directly connected with 220V alternating current, you can connect one pole first, and use another power cord to touch the other capacitor pin. If there is a clearly small spark when touching, it can be confirmed that this capacitor is charged, that is to say, this capacitor is not broken. Measure with a multimeter capacitance range. Adjust the function switch to the 20uF or 200uF range. Insert the test leads into the middle two holes and use the test leads to measure the two poles of the capacitor respectively. At this time, its capacity will be displayed. If it is a used capacitor, it must be discharged first before measurement.
For an analog multimeter, you can also use the capacitance measurement range of a digital meter. If an analog multimeter is used, generally the R×1K range is used. Connect the test leads to the two poles of the capacitor respectively.
At this time, the pointer of the multimeter will swing and then slowly return to zero or near zero. Such a capacitor is good. The larger the capacitance of the capacitor, the longer the charging time, and the slower the pointer swings towards 00. If the pointer does not move and the displayed resistance value is very small and does not move after connection, it can be confirmed that it is broken.
Detection with a digital multimeter. Check with a digital multimeter. Set the digital multimeter to an appropriate resistance range.
The red and black test leads contact the two poles of the measured capacitor respectively. At this time, the displayed value will gradually increase from 0 until the overflow symbol "1" is displayed. If it always shows 0, it means there is a short circuit inside the capacitor. If it always shows an overflow, it may be that there is an open circuit between the poles inside the capacitor, or the selected resistance range may be inappropriate.