Mitsubishi Electric 800 Series Instruction Manual page 588

Check Possible cause
points
Parameter Under V/F control, Pr.0 Torque boost setting
setting is improper.
Pr.78 Reverse rotation prevention
selection is set.
Pr.79 Operation mode selection setting is
incorrect.
Bias and gain (Pr.902 to Pr.905) settings are
improper.
Pr.13 Starting frequency setting is greater
than the set 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 is lower than Pr.13
Starting frequency for JOG operation.
Operation mode and a writing device do not
correspond.
Start signal operation selection is set by
Pr.250 Stop selection.
The motor has decelerated to a stop when
power failure deceleration stop function is
selected.
Performing auto tuning.
The automatic restart after instantaneous
power failure function or power failure stop
function has been activated.
(Performing overload operation during input
phase loss may cause voltage insufficiency,
and that may result in detection of power
failure.)
The motor test operation is selected under PM
motor control.
When the FR-CC2-C is used, the input logic
setting of the X10 signal is incorrect.
Load Load is too heavy.
Shaft is locked.
Countermeasure
Increase the 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.
Check the bias and gain (Pr.902 to Pr.905) settings.
Set 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 higher than Pr.13.
Check Pr.79 Operation mode selection, Pr.338
Communication operation command source, Pr.339
Communication speed command source, Pr.550 NET
mode operation command source selection and Pr.551 PU
mode operation command source selection, and select an
operation mode suitable for the purpose.
Check the Pr.250 setting and the 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.
When Pr.261 Power failure stop selection = "2 or 12", the
motor automatically restarts after the power is restored.
When offline auto tuning ends, press
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.)
Set Pr.872 Input phase loss protection selection ="1" (input
phase failure protection active).
Disable the automatic restart after instantaneous power failure
function and power failure stop function.
Reduce the load.
Increase the acceleration time if the function was activated
during acceleration.
Check the Pr.800 Control method selection setting.
Set Pr.599="0" to use the X10 signal with the NO contact input
specification, and Pr.599="1" (initial value for separated
converter types) to use the X10 signal with the NC contact
input specification.
Reduce the load.
Inspect the machine (motor).
Refer to
538
221
204
328
201,
226,
201, 202,
224
204,
550
458
353,
of the operation
241, 448,
458
145
553
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6. PROTECTIVE FUNCTIONS
6.5 Check first when you have a trouble
page
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