Table of Contents
Advertisement
3.3
Power-OFF and magnetic contactor (MC)
(1)
Inverter input side magnetic contactor (MC)
On the inverter input side, it is recommended to provide an MC for the following purposes.
(Refer to page 5 for selection.)
1) To release the inverter from the power supply when the fault occurs or when the drive is not functioning (e.g. emergency
stop operation). For example, MC avoids overheat or burnout of the brake resistor when heat capacity of the resistor is
insufficient or brake regenerative transistor is damaged with short while connecting an optional brake resistor.
2) To prevent any accident due to an automatic restart at restoration of power after an inverter stop made by a power failure
3) To separate the inverter from the power supply to ensure safe maintenance and inspection work.
If using an MC for emergency stop during operation, select an MC regarding the inverter input side current as JEM1038-AC-3
class rated current.
REMARKS
Since repeated inrush currents at power ON will shorten the life of the converter circuit (switching life is about 1,000,000 times.),
frequent starts and stops of the MC must be avoided. Turn ON/OFF the inverter start controlling terminals (STF, STR) to run/stop
the inverter.
MCCB
Three-phase AC
power supply
Operation preparation
OFF
ON
MC
MC
Start/Stop
RA
MC
Start
Stop
RA
(2)
Handling of inverter output side magnetic contactor
Switch the magnetic contactor between the inverter and motor only when both the inverter and motor are at a stop. When the
magnetic contactor is turned ON while the inverter is operating, overcurrent protection of the inverter and such will activate. If
an MC is provided to switch to the commercial power supply or for similar purposes under general-purpose motor control,
switch the MC after the inverter and motor have stopped.
NOTE
IPM motor is a synchronous motor with high-performance magnets embedded in the rotor. Motor terminals hold high-
voltage while the motor is running even after the inverter power is turned OFF. Before wiring or inspection, the motor
must be confirmed to be stopped. When the motor is driven by the load in applications such as fan and blower, a low-
voltage manual contactor must be connected at the inverter's output side, and wiring and inspection must be
performed while the contactor is open. Otherwise you may get an electric shock.
Power-OFF and magnetic contactor (MC)
Inverter
Filterpack
MC
R
R/L1
R0
S
S/L2
S0
T
T/L3
T0
P1
P1
T
*1
P
P/+
RA
STF(STR)
SD
Inverter start/stop circuit example
(When using Filterpack)
U
Motor
V
As shown on the left, always use the start
W
signal (ON or OFF of STF(STR) signal) to
make a start or stop.
C
When the power supply is 400V class, install a
B
stepdown transformer.
A
3
51
Advertisement
Table of Contents
