OBF fault meaning on the ATV58
OBF is over braking fault
Check the DEC time setting on the drive. If it is very low, try increasing to allow the drive a longer ramp down time.
Check the Line voltage on L1 L2 L3 to verify that it is within specifications. High line voltage will translate to high DC bus voltage.
Monitor the DC bus voltage.
If OBF appears on power up, verify that the display is not set to show the last fault on power up.
A dynamic brake resistor may be required if the load is overhauling.