YASKAWA V1000 Quick Start Manual page 93

Excessive regeneration when
overshoot occurs after acceleration.
Drive input power voltage is too
high.
The dynamic braking transistor is
damaged.
The braking transistor is wired
incorrectly.
Drive fails to operate properly due to
noise interference.
Load inertia has been set incorrectly.
Braking function is being used in
PM Open Loop Vector Control.
Motor hunting occurs.
Cause
There is phase loss in the drive input
power.
There is loose wiring in the drive
input power terminals.
There is excessive fluctuation in the
drive input power voltage.
There is poor balance between
voltage phases.
YASKAWA ELECTRIC TOEP C710606 14A YASKAWA AC Drive - V1000 Quick Start Guide
Enable the Overvoltage Suppression function (L3-11 = "1").
Lengthen the S-curve at acceleration end.
• Check the voltage.
• Lower drive input power voltage within the limits listed in the specifications.
Replace the drive.
• Check braking transistor wiring for errors.
• Properly rewire the braking resistor device.
• Review the list of possible solutions provided for controlling noise.
• Review the section on handling noise interference and check the control
circuit lines, main circuit lines and ground wiring.
• Check the load inertia settings when using KEB, overvoltage suppression or
Stall Prevention during deceleration.
• Adjust L3-25 (Load Inertia Ratio) in accordance with the load.
Connect a braking resistor.
• Adjust the parameters that control hunting.
• Set the hunting prevention gain (n1-02).
• Adjust the AFR time constant (n2-02 and n2-03) when in OLV Control.
• Use parameters n8-45 (PM Speed Feedback Detection Suppression Gain) and
n8-47 (Pull-In Current Compensation Time Constant).
Input Phase Loss
PF
Drive input power has an open phase or has a large imbalance of voltage
between phases. Detected when L8-05 = 1 (enabled).
• Check for wiring errors in the main circuit drive input power.
• Correct the wiring.
• Ensure the terminals are tightened properly.
• Apply the tightening torque specified in this manual to fasten the terminals.
• Check the voltage from the drive input power.
• Review the possible solutions for stabilizing the drive input power.
• Disable Input Phase Loss Detection (L8-05 = "0"). PF is detected if DC bus
ripple is too high. If it is disabled, there is no fault but the ripple is still too
high, thereby the capacitors are stressed more and lose lifetime.
• Stabilize drive input power or disable phase loss detection.
5.2 Fault Detection
Possible Solution
5
93