If the drive output switches at high speeds, it causes high frequency leakage current. To prevent electrical shock and fires caused by ground fault protection that is not sufficient, install an ELCB.
Use a high frequency ELCB at the power input side of the drive and make sure that each drive has a minimum cumulative sensitivity amperage of 30 mA. The specialized breaker only detects the leakage current from frequency bands that are dangerous to humans.
If a device does not have protection against high frequencies, high frequency leakage currents can cause the device to malfunction. If you have a malfunction on a device that does not have protection, decrease the carrier frequency of the drive, install a better breaker, or use an ELCB with a minimum cumulative sensitivity amperage of 200 mA for each drive.
These conditions can have an effect on leakage current:
To prevent damage and injury to personnel and drives, use a high-frequency ELCB that is rated for AC and DC power supplies.
Note:
Yaskawa recommends these ELCBs, which are designed to operate with high frequencies:
-
Mitsubishi Electric Corporation, NV series
-
Schneider Electric, NS series
You can use a molded-case circuit breaker (MCCB) as a replacement for an ELCB that is upstream in the power supply system.