Motor or machine is making abnormal acoustic
Disturbance due to EMI when the frequency
or torque command is given through analog
input terminal 1, 2, or 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
Resonance occurs. (output frequency)
Resonance occurs. (carrier frequency)
Auto tuning is not performed under
Advanced magnetic flux vector control,
Real sensorless vector control, or Vector
Gain adjustment during PID control is
The gain is too high under Real sensorless
vector control, Vector control, or PM
sensorless vector control.
Contact the motor manufacturer.
Operating with output phase loss
Inverter generates abnormal noise
The fan cover was not correctly installed
when a cooling fan was replaced.
6. PROTECTIVE FUNCTIONS
6.6 Check first when you have a trouble
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
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
Set a notch filter.
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
Check the calibration of set point and measured value.
During speed control, check the setting of Pr.820 Speed control P
During torque control, check the setting of Pr.824 Torque control
P gain 2.
Adjust machine/equipment so that there is no mechanical
Check the motor wiring.
Install the fan cover correctly.