Installing A Magnetic Contactor - YASKAWA A1000 Series Technical Manual

8.5 Installing Peripheral Devices
Figure 8.10
WARNING! Electrical Shock Hazard. Switch off and lock the MCCB (or ELCB) 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 ELCB from tripping. If a ELCB is required in the installation, always use an all current sensitive ELCB (Type B
according to IEC 60755) to ensure proper ground fault interruption.
Leakage currents generated by the drive during normal operation may trip a ELCB 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 ELCB trips spuriously consider changing these items or use a ELCB with a higher trip level.

◆ Installing a Magnetic Contactor

Install a magnetic contactor to the drive input for the purposes explained below.
■ Disconnecting the Power Supply
The drive should be shut off with a magnetic contactor (MC) when a fault occurs in any external equipment such as
braking resistors.
NOTICE: Do not connect electromagnetic switches or magnetic contactors to the output motor circuits without proper sequencing.
Improper sequencing of output motor circuits could result in damage to the drive.
NOTICE: Install a 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. To keep the drive from restarting automatically when power is restored after momentary power loss, install a magnetic contactor to
the drive input.
2. To have the drive continue operating through momentary power loss, set up a delay for the magnetic contactor so that it does not open
prematurely.
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. When using a braking unit, use a thermal relay on the braking resistors and configure a fault contact output
for the braking resistor unit to disconnect drive main power via an input contactor. Inadequate braking circuit protection could result in
death or serious injury by fire from overheating resistors.
382
A MCCB
C
A – Power supply
B – Drive
Figure 8.10 Power Supply Interrupt Wiring (Example)
YASKAWA ELECTRIC SIEP C710616 27C YASKAWA AC Drive A1000 Technical Manual
B
MC
R/L1
S/L2
T/L3
MC
MB
MC
MC
C – Control Power Supply
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