Mitsubishi Electric FR-D720S SC EC, Instruction Manual

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Troubleshooting Check first when you have troubles
FR-D700 SC EC 7 - 23
7.6.2 Motor or machine generates abnormal noise
7.6.3 Inverter generates abnormal noise
Check points Possible Cause Countermeasures
Refer to
Page
Input signal
Disturbance due to EMI when frequency
command is given from analog input (ter-
minal 2, 4).
Take countermeasures against EMI. 3-44
Parameter
Setting
Increase the Pr. 74 "Input filter time con-
stant" if steady operation cannot be per-
formed due to EMI.
6-152
Parameter
Setting
No carrier frequency noises (metallic
noises) are 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.
6-144
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.
6-42
Resonance occurs. (carrier frequency)
Change Pr. 72 "PWM frequency selection"
setting.
Changing the PWM carrier frequency pro-
duces an effect on avoiding the resonance
frequency of a mechanical system or a
motor.
6-144
Auto tuning is not performed under Gen-
eral-purpose magnetic flux vector control.
Perform offline auto tuning. 6-74
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.
6-242
Others Mechanical looseness
Adjust machine/equipment so that there is
no mechanical looseness.
—
Motor
Operating with output phase loss Check the motor wiring. —
Contact the motor manufacturer.
Check points Possible Cause Countermeasures
Refer to
Page
Fan
Fan cover was not correctly installed when
a cooling fan was replaced.
Install a fan cover correctly. 8-8