Braking Transistor Overload Fault

What does boL mean?

The braking transistor, an internal component responsible for dissipating regenerative energy, is experiencing an overload condition. This occurs when the drive's deceleration duty cycle or regenerative power is too high, or if the transistor itself is faulty. Persistent overload can lead to overheating and irreversible damage to the transistor, impairing the drive's ability to manage braking energy safely and effectively.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Evaluate the mechanical system for any excessive inertia or frequent braking demands that might require an external braking resistor or regenerative converter.

2. 4

   If the fault persists after adjusting parameters and external components, the internal braking transistor may be damaged, requiring drive replacement.