How to measure the starting capacitor is good or bad

The capacitor of the outdoor unit of the air conditioner plays the role of starting. Don't underestimate the capacitor. If the capacitor is broken,the entire air conditioner will not cool,and it is also a common failure that causes the air conditioner to fail to cool or heat.After seeing the effect of the capacitor, do you feel that the effect is great? How to judge the quality of the capacitor during maintenance? If the air conditioner capacitor is broken, it can usually be seen from the outside.Some capacitors are bulging and leaking, which can be seen from the outside. Some of them need a capacitance meter to measure, because it looks good in appearance, and it must be measured with tools from a specialized store.

Method 1: Very direct and simple method: Connect directly with 220V ac, you can connect one pole first, and touch the other capacitor pin with another power cord. If there is a small spark when touched, it can be sure that the capacitor is charged, that is to say, the capacitor is not broken.

Method 2: Pointer-type multimeter, you can also use the digital meter to measure capacitance.

If you use a pointer multimeter, generally use the R×1K file, and connect the test leads to the two poles of the capacitor. At this time, the pointer of the multimeter will swing, and then slowly return to zero or near zero. Such capacitors are good.The larger the capacity of the capacitor, the longer the charging time, and the slower the pointer swings in the direction of 00. If after connecting it, the pointer does not move and the resistance value displayed is very small and does not move, it must be bad.

Method 3: Check and measure with a digital multimeter.

Check with a digital multimeter, set the digital multimeter to the appropriate resistance level, and the red test lead and black test lead respectively touch the two poles of the capacitor under test. At this time, the display value will gradually increase from 000 until the overflow symbol "1" is displayed.If 000 is always displayed, it means that the capacitor is shorted internally. If overflow is always displayed, it may be an open circuit between the electrodes inside the capacitor, or the selected resistance file may be inappropriate.

In order to be able to see the charging process of the capacitor from the display screen, different resistance gears should be selected for capacitors with different capacities. The principle of selecting the resistance file is: when the capacitor is large, the low resistance file should be selected; when the capacitor capacity is small, the high resistance file should be selected.If you use a low-resistance file to check a small-capacity capacitor, because the charging time is very short, it will always display overflow, and the change process cannot be seen, so it is easy to misjudge that the capacitor is open.

If a high-resistance file is used to check a large-capacity capacitor, since the charging process is very slow, the measurement time needs to be relatively long. For capacitors above 0.1~1000uF, the resistance range can be selected according to the table (the charging time in the table refers to the time required for the display range to change from 000 to overflow).

The selection of resistance gear when measuring capacitors, resistance gear (Ω) measured capacitor range (uF) charging time S20M0.1~12~122M1~102~18200K10~1003~2020K100~10003~132K＞1000＞3 capacitor breakdown or after the circuit is open, it cannot be repaired, only a new capacitor of the same type can be replaced.In order to facilitate the selection during repair, the following table lists the capacity of the capacitor and the selection of the output power of the compressor motor for reference. Selection of capacitor capacity and compressor motor output power compressor motor output power (W) 0.2, 0.4, 0.75, 1.0, 1.5, 2.0, 2.2, 3.0, 3.7, 4.0, 5.0; Capacitor capacity (uF) 15, 20, 30, 30, 40, 50, 50, 50, 75, 75, 100.