YASKAWA A1000 Series

Digital Operator Display Fault Name
Cause Possible Solution
The braking transistor is damaged • Cycle power to the drive and check for reoccurrence of the fault.
•
Replace either the control board or the entire drive. For instructions on replacing the control board,
contact Yaskawa or a Yaskawa representative.
The control circuit is damaged
Digital Operator Display Fault Name
<1>
SC
Output Short Circuit or IGBT Fault
Short circuit or ground fault is detected.
Note: Fault
reset will not be received to prevent a short-circuit of the internal circuitry caused by
the IGBP fault.
<1> Available in drive software versions PRG: 1015 and later.
Digital Operator Display Fault Name
SEr
Too Many Speed Search Restarts
The number of Speed Search restarts exceeded the value set to b3-19.
Cause Possible Solution
Parameters related to Speed Search 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
Set b3-14 to 1 to enable Bi-Directional Speed Search.
STo
Pull-Out Detection
Motor pull out or step out has occurred. Motor has exceeded its pull-out torque.
SvE
Zero Servo Fault
Position deviation during zero servo.
<1>
THo
Thermistor Disconnect
The thermistor that detects motor temperature has become disconnected.
<1> Detected in models 4A0930 and 4A1200.
Digital Operator Display Fault Name
UL3
Undertorque Detection 1
The current has fallen below the minimum value set for Torque Detection Level 1 (L6-02) for longer than
the allowable time (L6-03).
Cause Possible Solution
Parameter settings are not appropriate for the
load
Check the settings of parameters L6-02 and L6-03.
There is a fault on the machine side Check the load for any problems.
Digital Operator Display Fault Name
UL4
Undertorque Detection 2
The current has fallen below the minimum value set for Torque Detection Level 2 (L6-05) for longer than
the allowable time (L6-06).
UL5
Mechanical Weakening Detection 2
The operation conditions matched the conditions set to L6-08.
<1>
UnbC
Current Unbalance
Current flow has become unbalanced.
<1> Detected in models 4A0930 and 4A1200.
5.2 Fault Detection
YASKAWA ELECTRIC TOEP C710616 41G YASKAWA AC Drive - A1000 Quick Start Guide
193
5
Troubleshooting