Mitsubishi Electric FR-A800, Instruction Manual

Page: 928 / 1042

Check first when you have a trouble Protective functions
6 - 40
6.6.3 Inverter generates abnormal noise
6.6.4 Motor generates heat abnormally
6.6.5 Motor rotates in the opposite direction
Check
points
Possible cause Countermeasure
Refer to
page
Fan
Fan cover was not correctly installed when a
cooling fan was replaced.
Install a fan cover correctly. 7-7
Check
points
Possible cause Countermeasure
Refer to
page
Motor
Motor fan is not working
(Dust is accumulated.) Clean the motor fan.
Improve the environment.
⎯
Phase to phase insulation of the motor is
insufficient.
Check the insulation of the motor.
⎯
Main
Circuit The inverter output voltage (U, V, W) are
unbalanced.
Check the output voltage of the inverter.
Check the insulation of the motor.
7-7
Parameter
Setting
Pr. 71 "Applied motor" setting is incorrect. Check the Pr. 71 "Applied motor" setting. 5-434
⎯
Motor current is large. Refer to "6.6.11 Motor current is too large". 6-43
Check
points
Possible cause Countermeasure
Refer to
page
Main
Circuit Phase sequence of output terminals U, V
and W is incorrect. Connect phase sequence of the output cables
(terminal U, V, W) to the motor correctly.
2-26
Input
signal
The start signals (forward rotation, reverse
rotation) are connected improperly. Check the wiring.
(STF: forward rotation, STR: reverse rotation) 2-36,
5-430
The polarity of the frequency command is
negative during the polarity reversible
operation set by Pr. 73 "Analog input
selection".
Check the polarity of the frequency command. 5-389
Input
signal
Parameter
Setting
Torque command is negative during torque
control under vector control.
Check the torque command value. 5-132