Yaskawa AC Drive Z1000 Bypass Technical Manual - Manual (Page 257)

Cause Possible Solutions
PI control is enabled, and the drive is consequently
adjusting the output frequency to match the PI setpoint.
The drive will only accelerate to the maximum output
frequency set in E1-04 while PI control is active.
If PI control is not necessary for the application, disable it by setting b5-01 to 0.
u Excessive Motor Oscillation and Erratic Rotation
Cause Possible Solutions
Poor balance between motor phases. Check drive input power voltage to ensure that it provides stable power.
Hunting prevention function is disabled. Set n1-01 to 1 to enable Hunting Prevention.
u Deceleration Takes Longer Than Expected
Cause Possible Solutions
L3-04 is set incorrectly. Check the Stall Prevention level during deceleration (L3-04).
The deceleration time is set too long. Set deceleration to more appropriate time (C1-02).
Insufficient motor torque.
• Assuming parameter settings are normal and that no overvoltage occurs when there is
insufficient torque, it is likely that the demand on the motor has exceeded the motor capacity.
• Use a larger motor.
Load exceeded the internal torque limit determined by
the drive rated current.
Switch to a larger capacity drive.
u Noise From Drive or Motor Cables When the Drive is Powered On
Cause Possible Solutions
Relay switching in the drive generates excessive noise.
• Lower the carrier frequency (C6-02).
• Install a noise filter on the input side of drive input power.
• Install a noise filter on the output side of the drive.
• Place the wiring inside a metal conduit to shield it from switching noise.
• Ground the drive and motor properly.
• Separate the main circuit wiring and the control lines.
• Make sure wires and the motor have been properly grounded.
u Ground Fault Circuit Interrupter (GFCI) Trips During Run
Cause Possible Solutions
Excessive leakage current trips GFCI.
• Check the wiring and rating of peripheral devices.
• Increase the GFCI sensitivity or use GFCI with a higher threshold.
• Lower the carrier frequency (C6-02).
• Reduce the length of the cable used between the drive and the motor.
• Install a noise filter or reactor on the output side of the drive. Set the carrier frequency to 2 kHz
when connecting a reactor.
• Disable the internal EMC filter.
u Connected Machinery Vibrates When Motor Rotates
n Unexpected Noise from Connected Machinery
Cause Possible Solutions
The carrier frequency is at the resonant frequency of
the connected machinery.
Adjust the carrier frequency using parameters C6-02 through C6-05.
The drive output frequency is the same as the resonant
frequency of the connected machinery.
• 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.
Note: The drive may have trouble assessing the status of the load due to white noise generated from using Swing PWM (C6-02 = 7 to A).
6.9 Troubleshooting without Fault Display
YASKAWA ELECTRIC SIEP YAIZ1B 01D YASKAWA AC Drive – Z1000 Bypass Technical Manual 257
6
Diagnostics & Troubleshooting