Motor Or Machine Is Making Abnormal Acoustic Noise - Mitsubishi Electric FR-F820-04750 Instruction Manual

Check first when you have a trouble
6.6.2

Motor or machine is making abnormal acoustic noise

Check
points
Input
signal
Parameter
setting
Parameter
setting
Others
Motor
6 - 34
Possible cause
Disturbance due to EMI when frequency or
torque command is given from analog input
(terminal 1, 2, 4).
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)
Resonance occurs. (carrier frequency)
Auto tuning is not performed under
Advanced magnetic flux vector control.
Gain adjustment during PID control is
insufficient.
The gain is too high under PM motor
control.
Mechanical looseness
Contact the motor manufacturer.
Operating with output phase loss
Countermeasure
Take countermeasures against EMI.
Increase the Pr. 74 "Input filter time constant" 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".
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.
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.
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.
Check the setting values of Pr. 820 "Speed
control P gain 1" and Pr. 824 "Torque control P
gain 1 (current loop proportional gain)".
Adjust machine/equipment so that there is no
mechanical looseness.
Check the motor wiring.
Protective functions
Refer to
page
3-1
5-258
5-85
5-85
5-173
5-85
5-297
5-347
5-52
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