n
Deceleration Takes Longer Than Expected when Using a Braking
Resistor
Cause
Possible Solutions
L3-04 is set incorrectly.
• Check the Stall Prevention Level during deceleration (L3-04).
• If a braking resistor option has been installed, disable Stall Prevention
during deceleration (L3-04 = “0”).
The deceleration time is set too long.
Set deceleration to more appropriate time (C1-02 and C1-04).
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.
n
Motor Hunting Occurs When Operating With a Light Load
Cause
Possible Solutions
Carrier frequency is too high.
Lower the carrier frequency setting C6-02.
Large V/f setting value at low speeds
triggers overexcitation.
• Use parameters E1-04 through E1-10 to set the V/f pattern in relation to
the load characteristics.
The maximum output frequency and the
base frequency reference are not set
properly in relationship to each other.
Set the proper values for the maximum output frequency and base frequency
(E1-04, E1-06).
Hunting Prevention is set up incorrectly. Adjust the hunting prevention gain (n1-02).
n
Noise From Drive or Output Lines 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.
n
Ground Fault Circuit Interrupter (GFCI) Trips During Run
Cause
Possible Solutions
Excessive leakage current trips MCCB.
• 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.
5.8 Troubleshooting without Fault Display
YASKAWA ELECTRIC TOEP C710606 25D YASKAWA AC Drive J1000 Installation & Start-Up Manual
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5
Troubleshooting
