Mitsubishi Electric FR-D720-0.4K Instruction Manual page 269

Check
points
Pr. 0 Torque boost setting is improper when V/F control is
used.
Pr. 78 Reverse rotation prevention selection is set.
Pr. 79 Operation mode selection setting is wrong.
Pr. 146 Built-in potentiometer switching setting is improper.
Bias and gain (calibration parameter C2 to C7) settings
are improper.
Pr. 13 Starting frequency setting is greater than the
running frequency.
Frequency settings of various running frequency (such
as multi-speed operation) are zero.
Especially, Pr. 1 Maximum frequency is zero.
Pr. 15 Jog frequency setting is lower than Pr. 13 Starting
frequency.
Parameter
Operation mode and a writing device do not match.
Setting
Start signal operation selection is set by the Pr. 250 Stop
selection
The motor is decelerated to a stop when power failure
deceleration stop function is selected.
Performing auto tuning.
Automatic restart after instantaneous power failure
function or power failure stop function is activated.
(Performing overload operation with single-phase
power input specification model may cause voltage
insufficiency, and results in a detection of power failure.)
Load is too heavy.
Load
Shaft is locked.
Others
Operation panel display shows an error (e.g. E.OC1).
Possible Cause
Check first when you have a trouble
Countermeasures
Increase Pr. 0 setting by 0.5% increments while
observing the rotation of a motor.
If that makes no difference, decrease the setting.
Check the Pr. 78 setting.
Set Pr. 78 when you want to limit the motor rotation to
only one direction.
Select the operation mode which corresponds with input
methods of start command and frequency command.
Set Pr. 146 ="1" (initial value) when not using FR-E500
operation panel (PA02).
Check the bias and gain (calibration parameter C2 to C7)
settings.
Set running frequency higher than Pr. 13.
The inverter does not start if the frequency setting signal
is less than the value set in Pr. 13.
Set the frequency command according to the
application.
Set Pr. 1 higher than the actual frequency used.
Set Pr. 15 Jog frequency higher than Pr. 13 Starting
frequency.
Check Pr. 79, Pr. 338, Pr. 339, Pr. 551, and select an
operation mode suitable for the purpose.
Check Pr. 250 setting and connection of STF and STR
signals.
When power is restored, ensure the safety, and turn
OFF the start signal once, then turn ON again to restart.
The motor restarts when Pr. 261 = "2".
When offline auto tuning ends, press
operation panel for the PU operation. For the External
operation, turn OFF the start signal (STF or STR).
This operation resets the offline auto tuning, and the
PU's monitor display returns to the normal indication.
(Without this operation, next operation cannot be
started.)
Disable the automatic restart after instantaneous
power failure function and power failure stop function.
Reduce the load.
Increase the acceleration time if the automatic restart
after instantaneous power failure function or power
failure stop function occurred during acceleration.
Reduce the load.
Inspect the machine (motor).
When any fault occurs, take an appropriate corrective
action, then reset the inverter, and resume the
operation.
Refer
to
page
75
163
168
241
154
99
84
92
166,
175
118
143
of the
106
137,
143
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