In the process of using leakage circuit breaker, tripping often occurs when using its frequency converter, so why?

這是因為我們在使用變頻器時，它的輸出波形中含有高次諧波，而電機及變頻器與電機之間的電纜就會產生泄漏電流，該泄漏電流跟工頻驅動電機時的電流相比之下會大許多，故而也就產生了跳閘現象。隔離斷路器一般用于高壓電器的控制。而塑殼斷路器能夠在電流超過跳脫設定后自動切斷電流。

This is because when we use the frequency converter, its output waveform contains high-order harmonics, and the motor and the cable between the frequency converter and the motor will produce leakage current, which will be much larger than the current when the motor is driven by power frequency, so the tripping phenomenon occurs. Isolation circuit breakers are generally used for the control of high-voltage electrical appliances. The molded case circuit breaker can automatically cut off the current when the current exceeds the trip setting.

這種情況下我們還應當使用的就是漏電保護器。當漏電斷路器的變頻器操作輸出側的漏電流大約為工頻操作時的3倍多時，外加電動機等處的漏電流，這時候我們所選擇的漏電保護器的動作電流就應該大于工頻時漏電流的10倍。

In this case, we should also use leakage protector. When the leakage current at the frequency converter operation output side of the leakage circuit breaker is more than 3 times that of the power frequency operation, plus the leakage current at the motor, the action current of the leakage protector we selected should be greater than 10 times that of the power frequency operation.