YASKAWA V1000 Series

5.10 Detailed Troubleshooting
252 YASKAWA TM.V1000.01 V1000 Drive Installation & Start-Up Manual (Preliminary 01-19-07)
■ Drive Does Not Allow Selection of Rotational Auto-Tuning
■ Motor Hunting Occurs at Low Speeds
■ Overvoltage Occurs When Running at a Constant Speed
■ Motor Stalls During Acceleration or With Large Loads
Cause Possible Solutions
The drive is in the incorrect motor control
method for Rotational Auto-Tuning.
• Check if the drive is set to V/f Control by accident (A1-02 = 0).
• Change the motor control method to Open Loop Vector Control
(A1-02 = “2”).
Cause Possible Solutions
Excessive load inertia in Open Loop
Vector Control.
• Excess load inertia can cause motor hunting in Open Loop Vector
Control due to slow motor response.
• Increase the speed feedback detection control time constant (n2-02)
from its default value of 50 ms to an appropriate level between 100 and
200 ms. Adjust this setting in combination with n2-03 (Feedback
Detection Control Time Constant 2).
Cause Possible Solutions
Excessive load inertia in Open Loop
Vector Control.
• Loads with a lot of inertia (fans, etc.) can trigger an overvoltage fault
when operating in Open Loop Vector Control.
• Switch to the V/f motor control method.
• Adjust the values set for the speed feedback detection control time
constant (n2-02, n2-03).
Cause Possible Solutions
Load is too heavy.
• Take the following steps to resolve the problem:
• Reduce the load.
• Increase the acceleration time.
• Increase motor capacity.
• Although the drive has a Stall Prevention function and a Torque
Compensation Limit function, accelerating too quickly or trying to drive
an excessively large load can exceed the capabilities of the motor.