YASKAWA GA800 Series, Technical Reference

Page: 117 / 1016

Electrical
Installation
3
3.10 Drive Wiring Protection
YASKAWA SIEPC71061737B GA800 Drive Technical Reference 117
3.10 Drive Wiring Protection
◆
Installing a Ground Fault Circuit Interrupter (GFCI)
When 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 a GFCI.
Use a high frequency GFCI 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 detects only 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 is not protected, decrease the carrier frequency of the drive,
switch to a better breaker, or use a GFCI with a minimum cumulative sensitivity amperage of 200 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 filter
To prevent damage and injury to personnel and drives, use a high-frequency GFCI that is rated for AC and DC power
supplies.
Note:
Yaskawa recommends these GFCIs, 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 a GFCI that is upstream in the power supply
system.
◆
Installing a Molded-Case Circuit Breaker (MCCB) or Ground Fault Circuit
Interrupter (GFCI)
Install a molded-case circuit breaker (MCCB) or a ground fault circuit interrupter (GFCI) for line protection between
the power supply and main circuit power supply input terminals R/L1, S/L2, and T/L3. The MCCB or GFCI gives
overload protection and also prevent damage to the main circuit and the devices that are wired to the main circuit.
Use the information in this section to select the correct MCCB or GFCI 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 MCCB or
GFCI as an alternative to overheat protection (150% for one minute at the rated output current) to prevent drive
faults.
•
When you connect more than one drive or the drive and other device to an MCCB or ELCB, refer to Figure 3.74 ,
use a magnetic contactor (MC), and set a sequence that de-energizes the drive when it outputs errors.
A - Power supply B - Drive
Figure 3.74 Connect an MCCB
WARNING! Electrical Shock Hazard. Use an MCCB, GFCI, or Magnetic Contactor (MC) to de-energize the drive before you wire the
main circuit terminal. If the main circuit terminal is energized during wiring, it will cause serious injury or death.