YASKAWA V1000 Series Technical Manual page 251

Cause
Motor-rated voltage is set too high in Open Loop Vector Control.
Auto-Tuning did not complete properly for Open Loop Vector Control. • Perform Auto-Tuning again.
Deceleration Takes Too Long With Dynamic Braking Enabled
n
Cause
L3-04 is set incorrectly.
The deceleration time is set too long.
Insufficient motor torque.
Reaching the torque limit.
Load exceeded the internal torque limit determined by the drive rated
current.
Motor Hunting Occurs When Operating With a Light Load
n
Cause
Carrier frequency is too high.
Large V/f setting value at low speeds triggers overexcitation.
The maximum output frequency and the base frequency reference are
not set properly in relationship to each other.
Hunting Prevention is disabled (V/f control only).
Load Falls When Brake is Applied (Hoist-Type Applications)
n
Cause
The timing for the brake to close and release is not set properly.
Insufficient DC Injection Braking.
Noise From Drive or Output Lines When the Drive is Powered On
n
Cause
Relay switching in the drive generates
excessive noise.
Ground Fault Circuit Interrupter (GFCI) Trips During Run
n
Cause
Excessive leakage current trips MCCB.
Connected Machinery Vibrates When Motor Rotates
n
Excessive Motor Oscillation and Erratic Rotation
Cause
Poor balance between motor phases.
YASKAWA ELECTRIC SIEP C710606 18A YASKAWA AC Drive – V1000 Technical Manual (Preliminary)
• The input voltage for the drive determines the maximum output voltage. A drive with an input of 200 Vac can only output
a maximum of 200 Vac. Open Loop Vector Control sometimes calculates an output voltage reference value that exceeds
the maximum drive output voltage level, resulting in a loss of speed control accuracy.
• Use a motor with a lower voltage rating (a vector control motor).
• Increase the input power voltage.
• 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").
Set deceleration to more appropriate time (C1-02, C1-04, C1-06, C1-08).
• 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.
• Check the settings for the torque limit (L7-01 through L7-04).
• If the torque limit is enabled, deceleration might take longer than expected because the drive cannot output more torque
than the limit setting. Ensure the torque limit is set to a large enough value.
• Increase the torque limit setting.
• If multi-function analog input terminal A1 or A2 is set to torque limit (H3-02 or H3-10 equals 10, 11, 12, or 15), ensure
that the analog input levels are set to the correct levels.
• Ensure H3-02 and H3-10 are set to the right levels.
• Ensure the analog input is set to the correct value.
Switch to a larger capacity drive.
Lower the carrier frequency setting C6-02.
• Select the proper V/f pattern (E1-03).
• Use parameters E1-04 through E1-10 to set the V/f pattern in relation to the load characteristics.
Set the proper values for the maximum output frequency and base frequency (E1-04, E1-06).
• Enable Hunting Prevention by setting n1-01 = "1".
• (OLV only) Increase the speed feedback detection control gain and time constant (n2-01, n2-02).
Use frequency reference detection for closing and releasing the brake.
• At start: Release the brake after creating enough torque.
• At stop: Close the brake when the motor still produces torque.
Make the following setting changes to hold the brake:
• Set the frequency detection inactive during baseblock (L4-07 = 0).
• Multi-function contact output terminal will switch on when the output frequency is greater than the frequency detection
level set in L4-01. Set L4-01 between 1.0 and 3.0 Hz.
• Slipping may occur when stopping because hysteresis is used in Frequency Reference 2 (where the frequency agree setting
in L4-02 is 2.0 Hz). To prevent this, change the setting to 0.1 Hz.
• Do not use the multi-function contact output setting "During Run" (H2-01 = 0) for the brake signal.
Increase the amount of DC Injection Braking (b2-02).
• 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.
• Increase the GFCE 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.
Check drive input power voltage to ensure that it provides stable power.
6.9 Troubleshooting Without Fault Display
Possible Solutions
Possible Solutions
Possible Solutions
Possible Solutions
Possible Solutions
Possible Solutions
Possible Solutions
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