YASKAWA V1000 Series

5.5 Fault Detection
YASKAWA TM.V1000.01 V1000 Drive Installation & Start-Up Manual (Preliminary 01-19-07) 221
Troubleshooting
5
LED Operator Display Fault Name
SEr
Too Many Speed Search Restarts
The number of speed search restarts has exceeded the number set to parameter
b3-19.
Cause Possible Solution
Speed Search parameters are set to
the wrong values.
• Reduce the detection compensation gain during Speed Search (b3-10).
• Increase the current level when attempting Speed Search (b3-17).
• Increase the detection time during Speed Search (b3-18).
• Repeat Auto-Tuning.
The motor is coasting in the opposite
direction of the run command.
Enable Bi-directional Speed Search (b3-14 = “1”).
LED Operator Display Fault Name
STO
Pull-Out Detection
Motor pull-out has occurred.
Cause Possible Solution
The wrong motor code has been set
(Yaskawa motors only).
• Enter the correct motor code for the PM being used into E5-01.
• For special-purpose motors, enter the correct data to all E5 parameters
according to the Test Report provided for the motor.
Load is too heavy.
• Increase the value set to n8-51 (Pull-In Current during Accel/Decel for PM).
• Reduce the load.
• Increase the motor or drive capacity.
Load inertia is too heavy. Increase n8-55 (Load Inertia for PM).
Acceleration and deceleration times
are too short.
• Increase the acceleration and deceleration times (C1-01 through C1-08).
• Increase the S-curve acceleration and deceleration times (C2-01).
LED Operator Display Fault Name
UL3
Undervoltage Detection 1
The current has fallen below the minimum value set for torque detection
(L6-02) for longer than the allowable time (L6-03).
Cause Possible Solution
Parameter settings are not
appropriate for the type of load.
Check the settings of parameters L6-02 and L6-03.
There is a problem with the load. Remove the cause of the fault.
LED Operator Display Fault Name
UL4
Undertorque Detection 2
The current has fallen below the minimum value set for torque detection
(L6-05) for longer than the allowable time (L6-06).
Cause Possible Solution
Parameter settings are not
appropriate for the type of load.
Check the settings of parameters L6-05 and L6-06.
There is a problem with the load. Remove the cause of the fault.