Mitsubishi Electric FR-F800 Series Instruction Manual page 616

6.6.2
Check
point
Input
Disturbance due to EMI when the
signal
frequency or torque command is given
Parameter
through analog input terminal 1, 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
setting
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
Others
Contact the motor manufacturer.
Motor Operating with output phase loss
6.6.3
Check
point
The fan cover was not correctly installed
Fan
when a cooling fan was replaced.
6.6.4
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
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Motor or machine is making abnormal acoustic
noise
Possible cause
Inverter generates abnormal noise
Possible cause
Motor generates heat abnormally
Possible cause
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Countermeasure
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.
Check the settings 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.
Countermeasure
Install the fan cover correctly.
Countermeasure
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 "6.6.11 Motor current is too large".
Refer to
90
355
218
218
289
218
383
419
190
—
Refer to
627
Refer to
—
—
632
379
618
6. PROTECTIVE FUNCTIONS
6.6 Check first when you have a trouble
1
2
page
3
4
5
6
7
8
9
10
page
page
615