When The Motor Does Not Start - Mitsubishi Electric FATEC FR-A800 Manual

5
BREAKDOWN MAINTENANCE
5.1.3

When the motor does not start

The motor does not start.
3-B
It does not start.
Has the motor
started so far?
NO
Is the operation
panel on?
YES
Is the wiring
correct?
YES
Is the control
signal correct?
YES
Is the start
signal input?
YES
Is the speed
command set?
YES
Is a value
other than "0" set in
D020 (Pr.78) Reverse
rotation prevention
YES
selection?
Check the forward and
NO
reverse direction.
Does electric
current flow?
NO
Are
the power supply
and wiring
NO
correct?
YES
Check the power
supply voltage
and wiring.
The inverter is faulty.
Replace it with a substitute
or return it to the factory to repair.
5.1 Troubleshooting
54
YES
It is not on.
NO
1-A
NO
Check the output and the wiring
between P and P1.
Misconnection or contact faults
NO
Turn OFF the MRS and RES signals.
When the automatic restart after
instantaneous power failure is selected,
turn ON the CS terminal.
NO
Turn ON the start signal.
RUN key of PU.
STF or STR signal
Command from the
communication
NO
Set the speed.
Setting via PU
External VR
(across terminals 2 and 5)
4 to 20 mA
(across terminals 4 and 5)
AU terminal is ON.
Multi-speed signal (RH, RM, RL)
Command from the communication
YES
Does OC or OL
alarm occur?
NO
What is set for the
control method C101
(Pr.80)?
Are
the torque boost
and starting frequency
YES
appropriate?
Check the following parameters.
G000 (Pr.0): Torque boost
F102 (Pr.13): Starting frequency
G001 (Pr.3): Base frequency
Has Pr. been
changed?
any abnormality such as
a break, contact faults, incorrect
wiring, or incorrect power
supply voltage
Has load become
temperature or humidity
affect the load?
The inverter is faulty.
Replace it with a substitute or
return it to the factory to repair.
Check the combined
mode of D000 (Pr.79).
Does the mechanical
YES
brake operate?
Is the load
too large?
Other than V/F control
9999 (V/F control)
NO
Check if the motor has any abnormality.
Check the type and capacity.
3-C
Accelerated.
YES
NO
Return the changed Pr.
to its original value and
check the status.
Does
YES
occur?
Check the wiring and
NO
power supply voltage.
YES
heavy?
NO
Does the
YES
NO
The load is large due to
fans, pumps, or agitators.
Review H500 (Pr.22) and
the capacity of the
inverter and motor.
3-A
OL, OC alarm
YES
Release the mechanical
NO
brake.
Check the release timing.
YES
NO Increase the capacity
of the motor or the inverter.
Has auto tuning NO
been performed?
Perform auto tuning.
YES
YES
Is a dedicated
motor used?
NO
Check the motor
specifications and type.