Revision April 2009    10-1 
Chapter 10  Troubleshooting 
If a fault is detected on the servo drive or motor a corresponding fault code will be shown on the drive's LED 
display. Fault codes can also be transmitted via communication, see P0-01 and P4-00 ~ P4-04 for display on 
controller or HMI. 
10.1  Fault Messages Table 
Servo Drive Fault Messages 
Fault Messages 
Display  Fault Name  Fault Description 
 
Overcurrent 
Main circuit current is higher than 1.5 multiple of motor’s 
instantaneous maximum current value. 
 
Overvoltage  Main circuit voltage has exceeded its maximum allowable value. 
 
Undervoltage  Main circuit voltage is below its minimum specified value. 
 
Reserved 
 
Regeneration error  Regeneration control operation is in error. 
 
Overload  Servo motor and drive is overload. 
 
Overspeed  Motor’s control speed exceeds the limit of normal speed. 
 
Abnormal pulse control 
command 
Input frequency of pulse command exceeds the limit of its 
allowable setting value. 
 
Excessive deviation 
Position control deviation value exceeds the limit of its allowable 
setting value. 
 
Watch dog execution 
time out  
Watch dog execution time out. 
 
Encoder error  Pulse signal is in error. 
 
Adjustment error 
Adjusted value exceeds the limit of its allowable setting value 
when perform electrical adjustment. 
 
Emergency stop 
activated 
Emergency stop switch is activated. 
 
Reverse limit switch 
error 
Reverse limit switch is activated. 
 
Forward limit switch 
error 
Forward limit switch is activated. 
 
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Call 1(800)985-6929 for Sales