Check First When You Have A Trouble; Motor Does Not Start - Mitsubishi Electric FR-E720-008 Instruction Manual

5.5

Check first when you have a trouble

POINT
If the cause is still unknown after every check, it is recommended to initialize the parameters (initial value) then
set the required parameter values and check again.
5.5.1

Motor does not start

Check
points
Appropriate power supply voltage is not applied.
(Operation panel display is not provided.)
Main
Circuit
Motor is not connected properly.
The jumper across P/+ and P1 is disconnected.
Start signal is not input.
Both the forward and reverse rotation start signals (STF,
STR) are input simultaneously.
Frequency command is zero.
(RUN LED on the operation panel is flickering.)
AU signal is not ON when terminal 4 is used for
frequency setting.
(RUN LED on the operation panel is flickering.)
Output stop signal (MRS) or reset signal (RES) is ON.
Input
(RUN LED on the operation panel flickers while MRS
Signal
signal is ON.)
Jumper connector of sink - source is wrongly selected.
(RUN LED on the operation panel is flickering.)
Shorting wires between S1 and PC, S2 and PC are
disconnected.
Voltage/current input switch is not correctly set for analog
input signal (0 to 5V/0 to 10V, 4 to 20mA).
(RUN LED on the operation panel is flickering.)
was pressed.
(Operation panel indication is
Two-wire or three-wire type connection is wrong.
Possible Cause
(PS).)

Check first when you have a trouble

Countermeasures
Power ON a moulded case circuit breaker (MCCB), an
earth leakage circuit breaker (ELB), or a magnetic
contactor (MC).
Check for the decreased input voltage, input phase loss,
and wiring.
Check the wiring between the inverter and the motor.
Securely fit a jumper across P/+ and P1.
When using a DC reactor (FR-HEL), remove the jumper
across P/+ and P1, and then connect the DC reactor.
Check the start command source, and input a start
signal.
PU operation mode:
External operation mode: STF/STR signal
Turn ON only one of the forward and reverse rotation
start signals (STF or STR).
If STF and STR signals are turned ON simultaneously in
the initial setting, a stop command is given.
Check the frequency command source and enter a
frequency command.
Turn ON the AU signal.
Turning ON the AU signal activates terminal 4 input.
Turn MRS or RES signal OFF.
Inverter starts the operation with a given start command
and a frequency command after turning OFF MRS or
RES signal.
Before turning OFF, ensure the safety.
Check that the control logic switchover jumper connector
is correctly installed.
If it is not installed correctly, input signal is not
recognized.
Short between S1 and PC, S2 and PC with shorting
wires.
Set Pr. 73, Pr. 267, and a voltage/current input switch
correctly, then input an analog signal in accordance with
the setting.
During the External operation mode, check the method
of restarting from a input stop from PU.
Check the connection.
Connect STOP signal when three-wire type is used.
Refer
to
page
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