Controller Overload (Deceleration)

What does OC4 mean?

The controller has overloaded during deceleration, often because the deceleration time (C0013) is set too short or the external brake resistor is inadequately dimensioned. Excessive regenerative energy not properly dissipated can damage the drive's DC bus components and lead to overvoltage faults.

• Deceleration time (Parameter C0013) is set too short for the load's inertia, generating excessive regenerative energy.
• External brake resistor is undersized (insufficient power rating in Watts) for the application's regenerative energy.
• External brake resistor resistance value is too high (Ohms), limiting current flow and energy dissipation.
• External brake resistor is disconnected or has a faulty wiring connection to the drive's BR+/BR- terminals.
• Brake chopper (integrated or external) is faulty or not activating correctly.

Click steps to track your progress.

1. 1

   1. Increase the deceleration time by adjusting Parameter C0013 (e.g., from 3.0s to 5.0s) to reduce regenerative energy peaks.

2. 2

   2. Verify the specified resistance (Ohms) and power rating (Watts) of the external brake resistor are appropriate for the application.

3. 3

   3. Measure the resistance of the external brake resistor at the drive's BR+/BR- terminals to ensure it matches the specified value.

4. 4

   4. Check the wiring continuity and secure connection of the external brake resistor to the drive terminals BR+ and BR-.

5. 5

   5. Monitor the DC bus voltage (e.g., via display parameter C0006) during deceleration to observe regeneration levels.