Motor Rotation Causes Unexpected Audible Noise From Connected Machinery; Motor Rotation Causes Oscillation Or Hunting; Pid Output Fault; The Starting Torque Is Not Sufficient - Omron Q2A Series Technical Manual

7.10 Troubleshooting Without Fault Display
◆

Motor Rotation Causes Unexpected Audible Noise from Connected Machinery

Causes
The carrier frequency and the resonant frequency of the connected
machinery are the same.
The drive output frequency and the resonant frequency of the connected
machinery are the same.
◆

Motor Rotation Causes Oscillation or Hunting

Causes
The frequency reference is assigned to an external source, and there is
electrical interference in the signal.
The cable between the drive and motor is too long.
The PID parameters are not sufficiently adjusted.
◆

PID Output Fault

Causes
There is no PID feedback input.
The detection level and the target value do not agree.
Reverse drive output frequency and speed detection. When output frequency
increases, the sensor detects a speed decrease.
◆

The Starting Torque Is Not Sufficient

Causes
Auto-Tuning has not been done in vector control method.
The control method was changed after doing Auto-Tuning.
Stationary Auto-Tuning for Line-to-Line Resistance was done.
◆

The Motor Rotates after the Drive Output Is Shut Off

Causes
DC Injection Braking is too low and the drive cannot decelerate correctly.
The stopping method makes the drive coast to stop.
300
Possible Solutions
• Adjust C6-02, C6-03, C6-04, and C6-05 [Carrier Frequency Selection, Carrier Upper
Frequency Limit, Carrier Lower Frequency Limit, and Carrier Freq Proportional Gain].
• Set C6-02 = 1 to 6 [Carrier Frequency Selection = Frequency other than Swing PWM].
Note:
If C6-02 = 7 to A [Carrier Frequency Selection = Swing PWM], the user will not know if the
noise comes from the drive or the machine.
• Adjust d3-01, d3-02, d3-03, and d3-04 [Jump Frequency 1, Jump Frequency 2, Jump
Frequency 3, and Jump Frequency Width].
• Put the motor on a rubber pad to decrease vibration.
Possible Solutions
Make sure that electrical interference does not have an effect on the signal lines.
• Isolate control circuit wiring from main circuit wiring.
• Use twisted-pair cables or shielded wiring for the control circuit.
• Increase the value of H3-13 [An.In FilterTime Constant].
• Do Auto-Tuning.
• Make the wiring as short as possible.
Adjust b5: PID CONTROL parameters.
Possible Solutions
• Examine the MFAI terminal settings.
• See if H3-02, H3-10, H3-06 = F [AI1 Function Selection, AI2 Function Selection, AI3
Function Selection = PID Fbk] is set.
• Make sure that the MFAI terminal settings agree with the signal inputs.
• Examine the connection of the feedback signal.
• Make sure that b5: PID CONTROL is set correctly.
Note:
If there is no PID feedback input to the terminal, the detected value is 0, which causes a PID
fault and also causes the drive to operate at maximum frequency.
Use H3-03, H3-11, and H3-07 [AI1 Gain Setting, AI2 Gain Setting, and AI3 Gain Setting] to
adjust PID target and feedback signal scaling.
Note:
PID control keeps the difference between the target value and detection value at 0. Set the
input level for the values relative to each other.
Set b5-09 = 1 [PID Output Level Selection = Reverse output].
Possible Solutions
Do Auto-Tuning.
Do Auto-Tuning again.
Do Rotational Auto-Tuning.
Possible Solutions
• Increase the value set in b2-02 [DCI Braking Current].
• Increase the value set in b2-04 [DCInj Time@Stop].
Set b1-03 = 0 or 2 [Stopping Method Selection = Ramp->Stop, DC Inj->Stop].
SIEPYEUOQ2A01A AC Drive Q2A Technical Manual