English-20 
Fault 
Name 
Fault Descriptions  Corrective Actions 
 
Over-current 
during 
acceleration 
1.  Short-circuit at motor output: Check for possible poor 
insulation at the output lines. 
2.  Torque boost too high: Decrease the torque compensation 
setting in Pr.54. 
3.  Acceleration Time too short: Increase the Acceleration Time.
4.  AC motor drive output power is too small: Replace the AC 
motor drive with the next higher power model. 
 
Over-current 
during 
deceleration 
1.  Short-circuit at motor output: Check for possible poor 
insulation at the output line. 
2.  Deceleration Time too short: Increase the Deceleration Time.
3.  AC motor drive output power is too small: Replace the AC 
motor drive with the next higher power model. 
 
Over-current 
during steady state 
operation 
1.  Short-circuit at motor output: Check for possible poor 
insulation at the output line. 
2.  Sudden increase in motor loading: Check for possible motor 
stall. 
3.  AC motor drive output power is too small: Replace the AC 
motor drive with the next higher power model. 
 
Internal EEPROM 
can not be 
programmed. 
1.  Turn off the power. 
2.  Check whether the input voltage falls within the rated AC 
drive input voltage. 
3.  Turn on the power. 
 
Internal EEPROM 
can not be read. 
1.  Check the connections between the main control board and 
the power board 
2.  Reset the drive to the factory settings. 
 
External Fault 
1.  Input EF (N.O.) on external terminal is closed to GND. Output 
U, V, W will be turned off. 
2.  Give RESET command after fault has been cleared. 
 
Auto accel/decel 
failure 
1.  Check if the motor is suitable for operation by AC motor 
drive. 
2. Check if the regenerative energy is too large. 
3.  Load may have changed suddenly. 
 
Ground fault 
When (one of) the output terminal(s) is grounded, short circuit 
current is more than 50% of AC motor drive rated current, the AC 
motor drive power module may be damaged. 
NOTE: The short circuit protection is provided for AC motor 
drive protection, not for protection of the user. 
1.  Check whether the IGBT power module is damaged. 
2.  Check for possible poor insulation at the output line. 
 
Communication 
error (see Pr.92) 
1.  Check the connection between the AC drive and computer 
for loose wires. 
2.  Check if the communication protocol is properly set. 
 
External Base 
Block. 
1.  When the external input terminal (B.B) is active, the AC 
motor drive output will be turned off. 
2.  Deactivate the external input terminal (B.B) to operate the AC 
motor drive again. 
 
OC hardware error  Return to the factory.