Mitsubishi Electric 800 Series, Instruction Manual, Page: 654 / 727

Check first when you have a trouble
PROTECTIVE FUNCTIONS
653
6
6.5.9
Operation mode is not changed properly
6.5.10
Operation panel display is not operating
6.5.11
Motor current is too large
Check
points
Possible cause Countermeasure
Refer to
page
Input
signal
Start signal (STF or STR) is ON.
Check that the STF and STR signals are off.
When either is ON, the operation mode cannot be changed.
43 , 421
Parameter
setting
Pr.79 Operation mode selection setting is
improper.
When the Pr.79 is set to "0 (initial value)", the operation mode is
the External operation mode at power ON. To switch to the PU
operation mode, press on the operation panel (press
on the parameter unit (FR-PU07)). At other settings (1 to
4, 6, 7), the operation mode is limited accordingly.
291
Operation mode and a writing device do not
correspond.
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.
291 , 301
Check
points
Possible cause Countermeasure
Refer to
page
Main
circuit
Control
circuit
Power is not input. Input the power. 32
Front
cover
Operation panel is not properly connected to
the inverter.
Check if the inverter front cover is installed securely. 21
Check
points
Possible cause Countermeasure
Refer to
page
Parameter
setting
Torque boost (Pr.0, Pr.46, Pr.112) setting is
improper under V/F control, so the stall
prevention function is activated.
Increase/decrease the Pr.0 Torque boost setting value by
0.5% increments so that stall prevention does not occur.
589
V/F pattern is improper when V/F control is
performed.
(
Pr.3, Pr.14, Pr.19 )
Set rated frequency of the motor to Pr.3 Base frequency .
Use Pr.19 Base frequency voltage to set the base voltage (for
example, rated motor voltage).
591
Change Pr.14 Load pattern selection according to the load
characteristic.
593
Stall prevention (torque limit) function is
activated due to a heavy load.
Reduce the load weight. ―
Set Pr.22 Stall prevention operation level (Torque limit
level) higher according to the load. (If Pr.22 is set too high, an
overcurrent trip (E.OC[]) is likely to occur.)
154 , 332
Check the capacities of the inverter and the motor. ―
Offline auto tuning is not performed under
Advanced magnetic flux vector control, Real
sensorless vector control, or vector control.
Perform offline auto tuning. 426
When PM sensorless vector control is
selected for a PM motor, and offline auto
tuning is not performed.
Perform offline auto tuning for a PM motor. 436