108 BBV28581 05/2010
Diagnostics and Troubleshooting
Fault detection codes that cannot be cleared automatically (continued)Code Name Possible causes Remedy
OCF Overcurrent • Parameters in the Motor control
menu drC- page 57 are not
correct
• Inertia or load too high
• Mechanical locking
• Check the parameters
• Check the size of the motor/drive/load
• Check the state of the mechanism
• Connect line chokes
• Reduce the Switching frequency SFr
page 59
• Check the ground connection of drive, motor
cable and motor insulation.
SCF1 Motor short circuit • Short-circuit or grounding at the
drive output
• Ground fault during running status
• Commutation of motors during
running status
• Significant current leakage to
ground if several motors are
connected in parallel
• Check the cables connecting the drive to the
motor, and the motor insulation
• Connect motor chokes
SCF3 Ground short circuit
SCF4 IGBT short circuit • Internal power component short
circuit detected at power on
• Contact your local Schneider Electric
representative
SOF Overspeed • Instability
• Overspeed associated with the
inertia of the application
• Check the motor
• Overspeed is 10% more than Maximum
frequency tFr page 57 so adjust this
parameter if necessary
• Add a braking resistor
• Check the size of the motor/drive/load
• Check parameters of the speed loop (gain
and stability)
tnF Auto-tuning • Motor not connected to the drive
• One motor phase loss
• Special motor
• Motor is rotating (being driven by
the load, for example)
• Check that the motor/drive are compatible
• Check that the motor is present during auto-
tuning
• If an output contactor is being used, close it
during auto-tuning
• Check that the motor is completely stopped