Chapter 6 Fault Code Information and Maintenance 
 VFD-EL-W 
6-3 
 
Fault Name  Fault Descriptions  Corrective Actions 
 
External Base Block 
1. When the external input 
terminals (B.B) (MI1–MI4) are 
active, the AC motor drive stops 
output. 
2. When changing the 
communication address 2002H 
bit2 = 1, the drive stops output. 
The “bb” disappears once the signal source is cleared. 
 
Over-current during 
acceleration 
1.  Check if the screws between the drive and motor are 
loosen. 
2.  Check for possible poor insulation between the U-V-W 
terminals to the motor. 
3.  Increase the Acceleration Time. 
4.  Decrease the torque compensation setting (Pr.07.02). 
5.  Replace the drive with a larger capacity model. 
 
Over-current during 
deceleration 
1.  Check for possible poor insulation between the U-V-W 
terminals to the motor. 
2.  Increase the Deceleration Time. 
3.  Replace the drive with a larger capacity model. 
 
Over-current during constant 
speed operation 
1.  Check for possible poor insulation between the U-V-W 
terminals to the motor. 
2.  Check for possible motor stall. 
3.  Replace the drive with a larger capacity model. 
 
External Fault 
1. When multi-function input 
terminals (MI1–MI4) are set to 
external fault, the AC motor 
drive stops output. 
2. When changing the 
communication address 2002H 
bit0 = 1, the drive stops output. 
The “EF” disappears once the signal source is cleared 
and reset. 
 
Internal EEPROM cannot be 
programmed. 
Return the unit to the factory. 
 
Internal EEPROM cannot be 
programmed. 
Return the unit to the factory. 
 
Internal EEPROM cannot be 
read. 
1.  Press RESET key to reset all parameters to defaults. 
2.  If the fault still exists, return the unit to the factory. 
 
Internal EEPROM cannot be 
read. 
1.  Press RESET key to reset all parameters to defaults. 
2.  If the fault still exists, return the unit to the factory. 
 
Wiring detection fault  U-phase error, return the unit to the factory. 
 
Wiring detection fault    V-phase error, return the unit to the factory. 
 
Wiring detection fault    W-phase error, return the unit to the factory. 
 
Wiring detection fault   
DC bus wiring detection error, return the unit to the 
factory. 
 
Wiring detection fault    Temperature sensor error, return the unit to the factory. 
 
Auto-acceleration/deceleration 
failure 
1.  Check if the motor is suitable for operation by the 
C 
motor drive. 
2.  Check if the regenerative energy is too high. 
3.  Check for sudden load changes.