Installing A Magnetic Contactor At The Power Supply Side - YASKAWA L1000A Technical Manual

8.5 Installing Peripheral Devices
Installing a Ground Fault Circuit Interrupter (GFCI)
■
Note: Use appropriate equipment for Ground Fault Circuit Interrupter (GFCI). This drive can cause a residual current with a DC
component in the protective earthing conductor. Where a residual current operated protective or monitoring device is used for
protection in case of direct or indirect contact, always use a GFCI of type B according to IEC/EN 60755.
Residual currents occurring in drive installations can contain AC, DC, and high frequency components that may prevent a
normal GFCI from operating as desired. If a GFCI is required in the installation, always use an all-current-sensitive
device (Type B according to IEC/EN 60755) to ensure proper ground fault interruption.
Leakage currents generated by the drive during normal operation may trip a GFCI 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 GFCI trips spuriously consider changing these items or use a GFCI with a higher trip level.
Note: Choose a GFCI designed specifically for an AC drive. The operation time should be at least 0.1 s with sensitivity amperage of at
least 200 mA per drive. The output waveform of the drive may cause an increase in leakage current. This may in turn cause the
leakage breaker to malfunction. Increase the sensitivity amperage or lower the carrier frequency to correct the problem.

◆ Installing a Magnetic Contactor at the Power Supply Side

Install a magnetic contactor (MC) to the drive input for the purposes explained below.
Disconnecting from the Power Supply
■
Shut off the drive with an MC when a fault occurs in any external equipment such as braking resistors.
NOTICE: Do not connect electromagnetic switches or MCs to the output motor circuits without proper sequencing. Improper
sequencing of output motor circuits could result in damage to the drive.
NOTICE: Install an MC on the input side of the drive when the drive should not automatically restart after power loss. To get the full
performance life out of the electrolytic capacitors and circuit relays, refrain from switching the drive power supply off and on more than
once every 30 minutes. Frequent use can damage the drive. Use the drive to stop and start the motor.
NOTICE: Use a magnetic contactor (MC) to ensure that power to the drive can be completely shut off when necessary. The MC should
be wired so that it opens when a fault output terminal is triggered.
Note: 1. Install an MC to the drive input side to prevent the drive from restarting automatically when power is restored after momentary power
loss.
2. Set up a delay that prevents the MC from opening prematurely to continue operating the drive through a momentary power loss.
Protecting the Braking Resistor or Braking Resistor Unit
■
Use an MC on the input side of the drive to protect a braking resistor or braking resistor unit from overheat or fire.
WARNING! Fire Hazard. Applications using a braking option should wire a thermal relay so that the output contactor opens when the
thermal relay trips. Inadequate braking circuit protection could result in death or serious injury by fire from overheating resistors.
WARNING! Fire Hazard. Confirm an actual motor overload condition is not present prior to increasing the thermal oL trip detection
setting. Check local electrical codes before making adjustments to motor thermal overload settings. Failure to comply can result in
death or serious injury by fire.
370 YASKAWA ELECTRIC SIEP C710616 38F YASKAWA AC Drive - L1000A Technical Manual