Mitsubishi FR-A800

Check first when you have a trouble
666
PROTECTIVE FUNCTIONS
6.6.2 Motor or machine is making abnormal acoustic
noise
6.6.3 Inverter generates abnormal noise
Check
points
Possible cause Countermeasure
Refer to
page
Input
signal
Disturbance due to EMI when frequency or
torque command is given from analog input
(terminal 1, 2, 4).
Take countermeasures against EMI. 82
Parameter
Setting
Increase the Pr.74 Input filter time constant if steady
operation cannot be performed due to EMI.
413
Parameter
Setting
No carrier frequency noises (metallic noises)
are generated.
In the initial setting, Pr.240 Soft-PWM operation selection is
enabled to change motor noise to an unoffending complex
tone. Therefore, no carrier frequency noises (metallic noises)
are generated.
Set Pr.240 = "0" to disable this function.
277
The motor noise increases due to activation of
the carrier frequency automatic reduction
function when the motor is driven overloaded.
Reduce the load.
Disable the automatic reduction function by setting Pr.260
PWM frequency automatic switchover = "0".
277
Resonance occurs. (output frequency)
Set Pr.31 to Pr.36, Pr.552 (Frequency jump).
When it is desired to avoid resonance attributable to the natural
frequency of a mechanical system, these parameters allow
resonant frequencies to be jumped.
346
Resonance occurs. (carrier frequency)
Change Pr.72 PWM frequency selection setting.
Changing the PWM carrier frequency produces an effect on
avoiding the resonance frequency of a mechanical system or a
motor.
277
Set a notch filter. 208
Auto tuning is not performed under Advanced
magnetic flux vector control, Real sensorless
vector control, or vector control.
Perform offline auto tuning. 442
Gain adjustment during PID control is
insufficient.
To stabilize the measured value, change the proportional band
(Pr.129) to a larger value, the integral time (Pr.130) to a slightly
longer time, and the differential time (Pr.134) to a slightly
shorter time.
Check the calibration of set point and measured value.
501
The gain is too high under Real sensorless
vector control, vector control, or PM
sensorless vector control.
During speed control, check the setting of Pr.820 Speed
control P gain 2.
192
During torque control, check the setting of Pr.824 Torque
control P gain 2.
225
Others
Mechanical looseness
Adjust machine/equipment so that there is no mechanical
looseness.

Contact the motor manufacturer.
Motor
Operating with output phase loss Check the motor wiring. 
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. 679