Справочник Пользователя для Mitsubishi Electronics FR-A700
421
Check first when you have a trouble
5
5.5.2
Motor or machine is making abnormal acoustic noise
Even if the carrier frequency (Pr. 72) is set to a value higher than 3kHz for a 55K or lower capacity inverter, the carrier
frequency is automatically lowered to as low as 2kHz in an overloaded operation at a low speed (output frequency lower than
3Hz). Acoustic noise from the motor increases, but it is not a fault. (Refer to page 284 for Pr. 72)
frequency is automatically lowered to as low as 2kHz in an overloaded operation at a low speed (output frequency lower than
3Hz). Acoustic noise from the motor increases, but it is not a fault. (Refer to page 284 for Pr. 72)
5.5.3
Inverter generates abnormal noise
5.5.4
Motor generates heat abnormally
Check
points
points
Possible Cause
Countermeasures
Refer
to
page
Input
signal
Disturbance due to EMI when frequency command is
given from analog input (terminal 1, 2, 4).
given from analog input (terminal 1, 2, 4).
Take countermeasures against EMI.
Parameter
Setting
Increase the Pr. 74 Input filter time constant if steady
operation cannot be performed due to EMI.
operation cannot be performed due to EMI.
Parameter
Setting
No carrier frequency noises (metallic noises) are
generated.
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.
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.
Resonance occurs. (output frequency)
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.
When it is desired to avoid resonance attributable to the
natural frequency of a mechanical system, these
parameters allow resonant frequencies to be jumped.
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.
Changing the PWM carrier frequency produces an effect
on avoiding the resonance frequency of a mechanical
system or a motor.
Set a notch filter.
Auto tuning is not performed under Advanced magnetic
flux vector control, Real sensorless vector control, or
vector control.
flux vector control, Real sensorless vector control, or
vector control.
Perform offline auto tuning.
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.
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.
The gain is too high under Real sensorless vector
control or vector control.
control or vector control.
During speed control, check the setting of Pr. 820 (Pr.
830) speed control P gain.
830) speed control P gain.
During torque control, check the setting of Pr. 824 (Pr.
834) torque control P gain.
834) torque control P gain.
Others
Mechanical looseness
Adjust machine/equipment so that there is no
mechanical looseness.
mechanical looseness.
—
Contact the motor manufacturer.
Motor
Operating with output phase loss
Check the motor wiring.
—
Check
points
points
Possible Cause
Countermeasures
Refer
to
page
Fan
Fan cover was not correctly installed when a cooling fan
was replaced.
was replaced.
Install the fan cover correctly.
Check
points
points
Possible Cause
Countermeasures
Refer
to
page
Motor
Motor fan is not working
(Dust is accumulated.)
(Dust is accumulated.)
Clean the motor fan.
Improve the environment.
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.
Check the insulation of the motor.
Parameter
Setting
The Pr. 71 Applied motor setting is wrong.
Check the Pr. 71 Applied motor setting.
—
Motor current is large.
Refer to "5.5.11 Motor current is too large"