Download  Print this page

Mitsubishi Electric FR-F740-00023 Instruction Manual: Motor Or Machine Is Making Abnormal Acoustic Noise; Inverter Generates Abnormal Noise; Motor Generates Heat Abnormally

F700 series.
Hide thumbs

Advertisement

Check first when you have a trouble
5.5.2

Motor or machine is making abnormal acoustic noise

When operating the inverter with the carrier frequency of 3kHz or more set in Pr. 72, the carrier frequency will automatically
decrease if the output current of the inverter exceeds the value in parenthesis of the rated output current on page 304. This
may cause the motor noise to increase. But it is not a fault.
Check
points
Input
signal
Disturbance due to EMI when frequency command is
Parameter
given from analog input (terminal 1, 2, 4).
Setting
No carrier frequency noises (metallic noises) are
generated.
Resonance occurs. (output frequency)
Parameter
Setting
Resonance occurs. (carrier frequency)
Gain adjustment during PID control is insufficient.
Mechanical looseness
Others
Contact the motor manufacturer.
Motor
Operating with output phase loss
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.
284
Possible Cause
Possible Cause
Possible Cause
Countermeasures
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.
Set Pr. 31 to Pr. 36 (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.
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.
Adjust machine/equipment so that there is no
mechanical looseness.
Check the motor wiring.
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"
Refer
to
page
40
161
153
77
153
219
——
——
Refer
to
page
294
Refer
to
page
——
——
291
99
287

Advertisement

Comments to this Manuals

Symbols: 0
Latest comments: