Overbraking

What does ObF mean?

This fault indicates a DC bus overvoltage condition, most commonly caused by the motor regenerating energy back to the drive, such as during rapid deceleration or when driving an inertial load. If the regenerated energy cannot be dissipated, it can cause the DC bus voltage to rise above safe limits. Persistent overvoltage can stress and damage the drive's power stage components (e.g., IGBTs).

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Check the incoming line voltage for stability, as transient spikes or high nominal voltage can contribute to DC bus overvoltage during regeneration.