Mechanical Vibration; Stable Pid Control Is Not Possible Or Control Fails - Omron SYSDRIVE 3G3MV SERIES User Manual

Maintenance Operations
Use a ground fault interrupter with a high leakage-current detection value (sensitivity amperage of
200 mA or more, operating time of 0.1 s or more) or one with high-frequency countermeasures for
Inverter use.
Reducing the carrier frequency value in n080 is also effective.
In addition, remember that a leakage current increases in proportion to the cable length. Normally,
approximately 5 mA of leakage current is generated for each meter of cable.

8-2-11 Mechanical Vibration

H Mechanical system makes unusual noise.
• Resonance between the characteristic frequency of the mechanical system and the carrier frequency.
There may be resonance between the characteristic frequency of the mechanical system and the
carrier frequency. If the motor is running with no problems and the machinery system is vibrating
with a high-pitched whine, it may indicate that this is occurring. To prevent this type of resonance,
adjust the carrier frequency value in n080.
• Resonance between the characteristic frequency of a machine and the output frequency of the
Inverter.
There may be resonance between the characteristic frequency of a machine and the output fre-
quency of the Inverter. To prevent this from occurring, use the frequency jump function with the
constants set in n083 through n086 to change the output frequency or install vibration-proof rubber
on the motor base to prevent the resonance of the mechanical system.
H Vibration and hunting are occurring.
• Influence by the torque compensation function or the slip compensation function.
The torque compensation function or the slip compensation function of the Inverter may influence
the characteristic frequency of the mechanical system, causing vibration or hunting. In that case,
increase the time constants in n104 for torque compensation and in n112 for slip compensation. The
larger these time constants are, however, the slower the response speed of the torque compensa-
tion function and slip compensation function will be.
H Motor vibrates excessively and does not rotate normally.
• Motor Phase Interruption
If one or two of the three phases of the motor are open, the motor will vibrate excessively and will not
rotate. Check that the motor is wired correctly without any disconnection. The same phenomenon
will occur if the output transistor of the Inverter is open and damaged. Check the balance of the
Inverter's output voltage as well.

8-2-12 Stable PID Control is Not Possible or Control Fails

H PID control is not possible with vibration or hunting.
• PID control gain adjustment is insufficient.
Check the frequency of vibration and adjust the proportional (P) control, integral (I) control, and
derivative (D) control of the Inverter. Refer to 6-3-7 PID Adjustments.
Chapter 8
8-19