Mitsubishi Electric 800 Series Instruction Manual page 592

6.5.9 Operation mode is not changed properly
Check Possible cause
points
Input signal Start signal (STF or STR) is ON.
Parameter Pr.79 Operation mode selection setting is
setting improper.
Operation mode and a writing device do not
correspond.
6.5.10 Operation panel display is not operating
Check Possible cause
points
Main circuit Power is not input.
Control
circuit
Front cover Operation panel is not properly connected to
the inverter.
6.5.11 Motor current is too large
Check Possible cause
points
Parameter Torque boost (Pr.0, Pr.46) setting is improper
setting under V/F control, so the stall prevention
function is activated.
V/F pattern is improper when V/F control is
performed.
(Pr.3, Pr.14, Pr.19)
Stall prevention function is activated due to a
heavy load.
Offline auto tuning is not performed under
Advanced magnetic flux vector control.
When PM motor control is selected for a PM
motor, and offline auto tuning is not performed.
Countermeasure
Check that the STF and STR signals are off.
When either is ON, the operation mode cannot be changed.
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 parameter unit (FR-PU07)). At other settings (1 to
4, 6, 7), the operation mode is limited accordingly.
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.
Countermeasure
Input the power.
Check if the inverter front cover is installed securely.
Countermeasure
Increase/decrease the Pr.0 Torque boost setting value by
0.5% increments so that stall prevention does not occur.
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).
Change Pr.14 Load pattern selection according to the load
characteristic.
Reduce the load weight.
Set Pr.22 Stall prevention operation level higher according to
the load. (If Pr.22 is set too high, an overcurrent trip (E.OC[]) is
likely to occur.)
Check the capacities of the inverter and the motor.
Perform offline auto tuning.
Perform offline auto tuning for a PM motor.
50,
204
on the operation panel (press
204,
39
28
538
539
541
―
257
―
353
363
6. PROTECTIVE FUNCTIONS
6.5 Check first when you have a trouble
3
Refer to
page
4
550
5
5
214
5
6
Refer to
page
7
8
9
Refer to
page
10
591