Current Monitoring/Detection (Rcm/Rcd) - YASKAWA A1000 Technical Manual

8.5 Installing Peripheral Devices
 Installing a Molded Case Circuit Breaker (MCCB) and Equipment for Residual

Current Monitoring/Detection (RCM/RCD)

Install a MCCB or an RCM/RCD for line protection between the power supply and the main circuit power supply input
terminals R/L1, S/L2, and T/L3. This protects the main circuit and devices wired to the main circuit while also providing
overload protection.
NOTICE: Prevent Equipment Damage. For models CIMR-A4A0930 and 4A1200, make sure to install a fuse and equipment for
residual current monitoring/detection (RCM/RCD). Failure to comply may result in serious damage to the facilities in case the drive is
defected.
Consider the following when selecting and installing a MCCB or an RCM/RCD:
• The capacity of the MCCB or RCM/RCD should be 1.5 to 2 times the rated output current of the drive. Use a MCCB or
an RCM/RCD with an operation characteristics so that the MCCB or RCM/RCD does not trip faster than the drive
overload protection works (shuts off the drive after 1 min. operation at 150% of the drive rated current).
• If several drives are connected to one MCCB or RCM/RCD, use a sequence that shuts the power OFF when an error
occurs in one drive by using magnetic contactor (MC) as shown in the following figure.
Figure 8.21
WARNING! Electrical Shock Hazard. Switch off and lock the MCCB (or RCM/RCD) and MC before wiring terminals. Failure to comply
may result in serious injury or death.

Installing a Leakage Breaker
Residual currents occurring in drive installations can contain AC, DC and high frequency components that may prevent a
normal RCM/RCD from tripping. If an RCM/RCD is required in the installation, always use all current sensitive RCM/
RCD (Type B according to IEC/EN 60755) to ensure proper ground fault interruption.
Leakage currents generated by the drive during normal operation may trip an RCM/RCD even if a ground fault is not
present.
Factors that influence the leakage current are:
• Size of the AC drive
• AC drive carrier frequency
• Motor cable type and length
• EMI/RFI filter
If the RCM/RCD trips spuriously consider changing these items or use an RCM/RCD with a higher trip level.
430
A MCCB or RCM/RCD
C
A – Power supply
B – Drive
Figure 8.23 Power Supply Interrupt Wiring (Example)
YASKAWA ELECTRIC SIEP C710616 27G YASKAWA AC Drive A1000 Technical Manual
B
MC
R/L1
S/L2
T/L3
MC
MB
MC
MC
C – Control Power Supply