Overcurrent during DC-injection braking

What does OC1 mean?

An overcurrent (OC1) TRIP occurs if, during DC-injection braking (GSB) at high motor speeds, the residual voltage from magnetism and high speed generates an excessive motor current. This happens because the pulse inhibit (DCTRL-IMP) set during braking is too short.

• DC injection braking activated at too high a motor speed (P0-03), generating excessive back EMF that combines with the injected DC current.
• Parameter C0201 (DC-Injection Braking Enable) or C0202 (DC-Injection Braking Current) configured inappropriately for the motor or application.
• Braking ramp time (P1-10) set too short, forcing rapid deceleration and high regenerative energy during the transition to DC braking.
• Motor's residual magnetism or inertia causing high generated voltage when DC braking is initiated, leading to overcurrent.
• Drive hardware fault in the output stage leading to uncontrolled current during DC injection braking.

Click steps to track your progress.

1. 1

   1. Adjust parameter C0201 (DC-Injection Braking Enable) to ensure DC braking is only initiated below a safe motor speed threshold (P0-03).

2. 2

   2. Reduce parameter C0202 (DC-Injection Braking Current) to a lower value, then gradually increase while monitoring motor current (P0-04).

3. 3

   3. Increase the deceleration ramp time (P1-10) to allow the motor speed (P0-03) to decay sufficiently before DC braking engages.

4. 4

   4. Verify the motor's rated current (P2-03) and ensure C0202 does not exceed this value or the drive's capabilities.

5. 5

   5. Check for external load conditions that might be driving the motor during deceleration, increasing its speed before DC braking.