3.10 Drive Wiring Protection96 YASKAWA SIEPC71061753A GA500 Technical Manual3.10 Drive Wiring Protection◆ Installing a Earth Leakage Circuit Breaker (RCM/RCD)When the drive output does switches at high speeds, it causes high frequency leakage current. To preventelectrical shock and fires caused by ground fault protection that is not sufficient, install an RCM/RCD.Use a high frequency RCM/RCD at the power input side of the drive and make sure that each drive has aminimum cumulative sensitivity amperage of 30 mA. The specialized breaker detects only the leakage currentfrom frequency bands that are dangerous to humans.If a device does not have protection against high frequencies, high frequency leakage currents can cause thedevice to malfunction. If you have a malfunction on a device that is not protected, decrease the carrier frequencyof the drive, switch to a better breaker, or use an RCM/RCD with a minimum cumulative sensitivity amperage of200 mA for each drive.These conditions can have an effect on leakage current:• Drive capacity• Carrier frequency• Wiring distance and types of motor cables• EMI/RFI filterTo prevent damage and injury to personnel and drives, use a high-frequency RCM/RCD that is rated for AC andDC power supplies.Note:Yaskawa recommends the following RCMs/RCDs, which are designed to operate with high frequencies.• Mitsubishi Electric Corporation; NV series• Schneider Electric; NS seriesYou can use a molded-case circuit breaker (MCCB) as a replacement for an RCM/RCD that is upstream in thepower supply system.◆ Install a Molded-Case Circuit Breaker (MCCB) or Residual Current Monitor/Device (RCM/RCD)Install a molded-case circuit breaker (MCCB) or a ground fault circuit interrupter (RCM/RCD) for line protectionbetween the power supply and main circuit power supply input terminals R/L1, S/L2, and T/L3. The MCCB/RCM/RCD give overload protection and also prevent damage to the main circuit and the devices that are wired tothe main circuit.Use the information in this section to select the correct MCCB or RCM/RCD and to safely connect the device.• The capacity of the MCCB or GFCI must be 1.5 to 2 times the rated output current of the drive. Use an MCCBor RCM/RCD as an alternative to overheat protection (150% for one minute at the rated output current) toprevent drive faults.• When you connect more than one drive to one MCCB or RCM/RCD that is shared between multiple drives orwith other equipment, refer to Figure 3.53 and use a magnetic contactor (MC) and set a sequence that de-energizes the drive when it outputs errors.A - Power supply B - DriveFigure 3.53 Connect an MCCBWARNING! Electrical Shock Hazard. Use an MCCB, RCM/RCD, or Magnetic Contactor (MC) to de-energize the drive beforeyou wire the main circuit terminal. If the main circuit terminal is energized during wiring, it will cause serious injury or death.
