How can resolve problem 7191 BC short circuit Fault in ABB ACS880 Drive ?
Cause : Short circuit in brake chopper IGBT.
1. Ensure brake resistor is connected and not damaged.
2. Check the electrical specifications of the brake resistor against the Hardware manual.
3. Replace brake chopper (if replaceable).
Other Useful Link For ACS880 Drive
7191 BC Short Circuit Fault in ABB ACS880 Drive indicates that the drive has detected a short circuit in the Brake Chopper (BC) IGBT circuit. The brake chopper is responsible for dissipating regenerative energy through the brake resistor during motor deceleration. When a short circuit is detected in the brake chopper circuit, the drive trips to protect the power components.
Possible Causes:
- Short circuit in the brake chopper IGBT.
- Damaged brake resistor.
- Incorrect brake resistor specifications.
- Short circuit in brake resistor wiring.
- Faulty brake chopper module.
- Internal failure of the brake chopper power circuit.
- Damaged brake resistor terminals or connections.
- Excessive regenerative energy causing stress on the brake chopper.
- Incorrect installation of the braking system.
- Internal drive hardware fault.
Solutions:
- Verify that the brake resistor is properly connected.
- Inspect the brake resistor for physical damage, overheating, or burn marks.
- Measure the brake resistor resistance and compare it with the specified value.
- Check the brake resistor wiring for short circuits, loose connections, or damaged insulation.
- Compare the brake resistor specifications with the requirements listed in the drive Hardware Manual.
- Ensure that the brake resistor power rating and resistance value are suitable for the application.
- Inspect all brake chopper connections and terminals.
- Check for signs of damage to the brake chopper circuitry.
- If the brake chopper is a replaceable unit, replace the brake chopper module.
- After repairs, reset the fault and monitor braking operation.
Additional Information
The 7191 BC Short Circuit Fault is associated with the drive's braking system and is usually caused by a fault in one of the following components:
- Brake chopper IGBT.
- Brake resistor.
- Brake resistor wiring.
- Brake chopper power circuit.
A faulty brake resistor can overload the brake chopper and eventually damage the IGBT. Therefore, both the brake resistor and brake chopper should always be checked together when troubleshooting this fault.
Recommended Troubleshooting Sequence
- Inspect the brake resistor.
- Verify brake resistor specifications.
- Check brake resistor wiring and connections.
- Measure resistor resistance.
- Inspect the brake chopper module.
- Replace the brake chopper if defective.
- Test the drive under controlled deceleration conditions.
Regular inspection of the braking system and using the correct brake resistor according to ABB specifications can help prevent recurring 7191 BC Short Circuit Faults in ABB ACS880 drives.
