Inverter Generates Abnormal Noise; Motor Generates Heat Abnormally; Motor Rotates In The Opposite Direction; Speed Greatly Differs From The Setting - Mitsubishi Electric FR-D720-008 Instruction Manual

5.5.3

Inverter generates abnormal noise

Check
points
Fan cover was not correctly installed when a cooling fan
Fan
was replaced.
5.5.4

Motor generates heat abnormally

Check
points
Motor fan is not working
Motor
(Dust is accumulated.)
Phase to phase insulation of the motor is insufficient.
Main
The inverter output voltage (U, V, W) are unbalanced.
Circuit
Parameter
The Pr. 71 Applied motor setting is wrong.
Setting
—
Motor current is large.
5.5.5

Motor rotates in the opposite direction

Check
points
Main
Phase sequence of output terminals U, V and W is
Circuit incorrect.
The start signals (forward rotation, reverse rotation) are
connected improperly.
Input
Adjustment by the output frequency is improper during
signal
the reversible operation with Pr. 73 Analog input selection
setting.
Parameter
Pr. 40 RUN key rotation direction selection setting is
Setting incorrect.
5.5.6

Speed greatly differs from the setting

Check
points
Frequency setting signal is incorrectly input.
Input
signal The input signal lines are affected by external noise.
Pr. 1, Pr. 2, Pr. 18, calibration parameter C2 to C7 settings
Parameter
are improper.
Setting
Pr. 31 to Pr. 36 (frequency jump) settings are improper.
Load
Parameter
Stall prevention is activated due to a heavy load.
Setting
Motor
Possible Cause
Possible Cause
Possible Cause
Possible Cause
Check first when you have some troubles
Countermeasures
Install a fan cover correctly.
Countermeasures
Clean the motor fan.
Improve the environment.
Check the insulation of the motor.
Check the output voltage of the inverter.
Check the insulation of the motor.
Check the Pr. 71 Applied motor setting.
Refer to "5.5.11 Motor current is too large"
Countermeasures
Connect phase sequence of the output cables (terminal
U, V, W) to the motor correctly
Check the wiring. (STF: forward rotation , STR: reverse
rotation)
Check the setting of Pr. 125, Pr. 126, C2 to C7.
Check the Pr. 40 setting.
Countermeasures
Measure the input signal level.
Take countermeasures against EMI such as using
shielded wires for input signal lines.
Check the settings of Pr. 1 Maximum frequency, Pr. 2
Minimum frequency, Pr. 18 High speed maximum frequency.
Check the calibration parameter C2 to C7 settings.
Narrow down the range of frequency jump.
Reduce the load weight.
Set Pr. 22 Stall prevention operation level higher according
to the load. (Setting Pr. 22 too large may result in
frequent overcurrent trip (E.OC ).)
Check the capacities of the inverter and the motor.
Refer
to
page
272
Refer
to
page
—
—
267
101
263
Refer
to
page
15
20
150
235
Refer
to
page
—
38
81
151
5
82
—
77
—
261