YASKAWA V1000 Series Technical Manual page 252

6.9 Troubleshooting Without Fault Display
Unexpected Noise from Connected Machinery
Cause
The carrier frequency is at the resonant frequency of the connected
machinery.
The drive output frequency is the same as the resonant frequency of the
connected machinery.
Note: The drive may have trouble assessing the status of the load due to white noise generated when using Swing PWM (C6-02 = 7 to A, or 7 if set for Normal Duty).
Oscillation or Hunting
n
Cause
Insufficient tuning in Open Loop Vector Control.
Auto-Tuning has not yet been performed (required for Open Loop
Vector Control).
Insufficient tuning in Open Loop Vector Control.
Gain is too low when using PID control.
The frequency reference is assigned to an external source.
The cable between the drive and motor is too long.
PID output fault
n
Cause
No PID feedback input.
The level of detection and the target value do not correspond with each
other.
Reverse drive output frequency and speed detection. When output
frequency rises, the sensor detects a speed decrease.
Insufficient Motor Torque
n
Cause
Auto-Tuning has not yet been performed (required for OLV Control). Perform Auto-Tuning.
The control mode was changed after performing Auto-Tuning.
Only Line-to-Line Resistance Auto-Tuning was performed.
Motor Rotates After the Drive Output is Shut Off
n
Cause
Low DC Injection Braking and the drive cannot decelerate properly.
OV or Speed Loss Occurs When Starting into a Rotating Load
n
Cause
The load is already rotating when the drive is trying to start it.
Output Frequency is not as High as Frequency Reference
n
Cause
Frequency reference is set within the range of the Jump Frequency.
252
Adjust the carrier frequency using parameters C6-02 through C6-05.
• Adjust the parameters used for the Jump Frequency function (d3-01 through d3-04) to skip the problem-causing bandwidth.
• Place the motor on a rubber pad to reduce vibration.
Adjust the following parameters in the order listed to get better gain.
An increase in gain should be followed with an increase in the primary delay time constant.
• C4-02 (Torque Compensation Primary Delay Time)
• n2-01 (Speed Feedback Detection Control [AFR] Time Constant 1)
• C3-02 (Slip Compensation Primary Delay Time)
The response for torque compensation and slip compensation will drop as the time constant is increased.
Perform Auto-Tuning.
Set motor parameters after calculating the proper values.
Change the motor control method to V/f Control (A1-02 = "0").
Adjust the following parameters in the order listed to get better gain.
An increase in gain should be followed with an increase in the primary delay time constant.
• C4-02 (Torque Compensation Primary Delay Time)
• n2-02 (AFR Time Constant 1)
• n1-02 (Hunting Prevention Gain Setting)
The response for torque compensation and slip compensation will drop as the time constant is increased.
Check the period of oscillation and adjust P, I, and D settings accordingly.
• Ensure that noise is not affecting the signal lines.
• Separate main circuit wiring and control circuit wiring.
• Use twisted-pair cables or shielded wiring for the control circuit.
• Increase the analog input time filter constant (H3-13).
• Perform Auto-Tuning.
• Reduce the length of the cable.
• Check the multi-function analog input terminal settings.
• Set multi-function analog input terminal A1 or A2 for PID feedback (H3-02 or H3-10 = "B").
• A signal input to the terminal selection for PID feedback is necessary.
• Check the connection of the feedback signal.
• Check the various PID-related parameter settings.
• No PID feedback input to the terminal causes the value detected to be 0, causing a PID fault and the drive to operate at
max frequency.
• PID control keeps the difference between target and detection values at 0. Set the input level for the values relative to one
another.
• Use analog input gains H3-03/11 to adjust PID target and feedback signal scaling.
Set PID output for reverse characteristics (b5-09 = "1").
Perform Auto-Tuning again.
Perform Rotational Auto-Tuning.
• Adjust the DC Injection braking settings.
• Increase the value of b2-02 (DC Injection Braking Current).
• Increase the b2-04 (DC Injection Braking Time at Stop).
• Stop the motor using DC Injection braking. Restart the motor.
• Increase the value of b2-03 (DC Injection Braking Time at start).
• Enable Speed Search at start (b3-01 = "1").
• Set a multi-function input terminal for external Speed Search command (H1-oo="61" or "62" during restart).
4.17 on 79.
• Adjust the parameters used for the Jump Frequency function (d3-01 through d3-03).
• Enabling the Jump Frequency prevents the drive from outputting the frequencies specified in the Jump Frequency range.
YASKAWA ELECTRIC SIEP C710606 18A YASKAWA AC Drive – V1000 Technical Manual (Preliminary)
Possible Solutions
Possible Solutions
Possible Solutions
Possible Solutions
Possible Solutions
Possible Solutions
Possible Solutions
Figure