Braking Transistor Overload Fault

What does boL mean?

The internal or external braking transistor has experienced an overload condition, likely due to excessive regenerative energy being dissipated, exceeding its thermal or current limits. This can lead to damage to the transistor, braking resistor, or even the drive itself.

• Braking resistor resistance too high or too low (incorrectly sized for the application)
• Frequent or prolonged deceleration cycles leading to excessive regenerative energy generation
• Faulty braking transistor or associated control circuit within the drive.

Click steps to track your progress.

1. 1

   Verify the resistance value of the connected braking resistor using a multimeter and compare it to the drive's specifications.

2. 2

   Increase deceleration time parameters (e.g., C1-02, C1-04) to reduce regenerative energy peaks during braking.

3. 3

   Check the duty cycle and power rating of the braking resistor to ensure it is adequately sized for the application's braking requirements.