The quality of the contactor can be tested from the following aspects: first, the coil of the contactor, second, the contact of the contactor, and third, whether the suction of the electromagnetic mechanism is sufficient.

1、接触器的线圈

1. Coil of contactor

查看接触器线圈的额定电压，连接到相匹配的电源上，打开开关，查看接触器是否吸合。如果不吸合，说明接触器线圈存在故障问题。

Check the rated voltage of the contactor coil, connect it to the matching power supply, turn on the switch and check whether the contactor is closed. If not, the contactor coil is faulty.

或使用万用表测量接触器线圈的电压，对于没有相关经验的来说，可以用一个新的同样功率接触器的参数来作为参考。

Or use a multimeter to measure the voltage of the contactor coil. For those without relevant experience, the parameters of a new contactor with the same power can be used as a reference.

从哪几个方面来判断接触器的好坏

From which aspects can we judge the quality of the contactor

2、接触器的触头

2. Contact of contactor

如果接触器可以吸合，三相电源也正常，输出端却出现缺相的情况，可以通过测量三相任意两相的电压来判断。

If the contactor can be pulled in and the three-phase power supply is normal, but there is a lack of phase at the output end, it can be judged by measuring the voltage of any two phases of three phases.

这时需要检查接触器的主触头，查看有没有磨损烧毁的现象，如有则及时更换。

At this time, it is necessary to check the main contact of the contactor to see if it is worn or burned. If so, replace it in time.

3、电磁机构吸力不足

3. Insufficient suction of electromagnetic mechanism

一般表现为可以吸合，但主触头下端有缺相，施加外力外力后，缺相消失，这种也要及时更换。

Generally, it can be pulled in, but there is a lack of phase at the lower end of the main contact. After external force is applied, the lack of phase disappears, which should also be replaced in time.

电动机缺相的表现：振动加大、有异常声响、温度升高、转速下降、电流加大、启动时有强烈的嗡嗡声无法启动。

Performance of motor phase loss: increased vibration, abnormal sound, increased temperature, decreased speed, increased current, strong buzzing during startup, unable to start.

当出现上述现象时，应重 点检查电源和接触器有没有缺相现象，需要及时更换，以避免产生更大的损失。

When the above phenomena occur, focus on checking whether the power supply and contactor are out of phase and need to be replaced in time to avoid greater loss.