Motor Or Machine Is Making Abnormal Acoustic Noise; Inverter Generates Abnormal Noise; Motor Generates Heat Abnormally - Mitsubishi Electric 800 Series Instruction Manual

2.6.2 Motor or machine is making abnormal acoustic
noise
Check
point
Input
Disturbance due to EMI when the
signal
frequency or torque command is given
Parameter
through analog input terminal 2 or 4.
setting
No carrier frequency noises (metallic
noises) are generated.
The motor noise increases due to
activation of the carrier frequency
automatic reduction function when the
motor is driven overloaded.
Resonance occurs. (Output frequency)
Parameter
Resonance occurs. (Carrier frequency)
setting
Auto tuning is not performed under
Advanced magnetic flux vector control or
Real sensorless vector control.
Gain adjustment during PID control is
insufficient.
The gain is too high under Real
sensorless vector control, Vector control.
Mechanical looseness
Others
Contact the motor manufacturer.
Motor Operating with output phase loss
2.6.3

Inverter generates abnormal noise

Check
point
The fan cover was not correctly installed
Fan
when a cooling fan was replaced.
2.6.4

Motor generates heat abnormally

Check
point
The motor fan is not working.
(Dust is accumulated.)
Motor
Phase to phase insulation of the motor is
insufficient.
Main The inverter output voltage (U, V, W) are
circuit unbalanced.
Parameter The Pr.71 Applied motor setting is
setting incorrect.
— Motor current is too large
36
2. Protective Functions
2.6 Check first when you have a trouble
Possible cause
Possible cause
Possible cause
Take countermeasures against EMI.
Increase the Pr.74 Input filter time constant setting if steady operation cannot be
performed due to EMI.
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.
Reduce the load. Disable the automatic reduction function by setting Pr.260 PWM
frequency automatic switchover = "0". (As the load remains excessive, overload
may cause a protective function E.THT.)
Set Pr.31 to Pr.36, and 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.
Change the 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.
Perform offline auto tuning.
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.
During speed control, check the setting of Pr.820 Speed control P gain 2.
During torque control, check the setting of Pr.824 Torque control P gain 2 (current
loop proportional gain).
Adjust machine/equipment so that there is no mechanical looseness.
Check the motor wiring.
Install the fan cover correctly.
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 "Motor current is too large"
Countermeasure
Countermeasure
Countermeasure
(page 39).