5697 Charging Feedback Fault in ABB ACS880 Drive

5697 Charging Feedback in the ABB ACS880 Drive indicates that the drive has detected a missing charging feedback signal from the internal charging system. During power-up, the ACS880 uses a charging (precharge) circuit to safely charge the DC bus capacitors before connecting the main power circuit. The control unit monitors a dedicated charging feedback signal to confirm that the charging process has started and completed correctly.

If the expected feedback signal is missing or invalid, the drive generates Fault 5697 to prevent the power unit from operating without proper DC bus charging, protecting the drive from excessive inrush current and possible damage to the power electronics.

This fault generally indicates a problem with the charging circuit, charging feedback signal, associated wiring, or control hardware rather than a failure of the motor.

Possible Causes

• Missing charging feedback signal.
• Faulty charging (precharge) circuit.
• Defective charging contactor.
• Charging contactor coil failure.
• Faulty charging resistor.
• Loose or damaged charging feedback wiring.
• Poor connection between the charging system and the control unit.
• Defective charging feedback sensor or monitoring circuit.
• Faulty auxiliary power supply to the charging circuit.
• Defective control board input circuit.
• Charging contactor fails to close during startup.
• Internal power unit hardware failure.
• Damaged internal PCB or charging circuitry.
• Electrical surge affecting the charging circuit.
• Moisture or contamination causing poor electrical connections.
• Failure after replacement of the control board or power unit.

Solutions

• Cycle power to the drive and check whether the fault clears.
• Inspect the charging system for proper operation.
• Verify that the charging contactor operates correctly during startup.
• Check the charging contactor coil and its control voltage.
• Inspect the charging resistor for damage or open circuit.
• Verify the charging feedback signal reaches the control unit.
• Inspect the charging feedback wiring for loose or damaged connections.
• Ensure all internal connectors are securely seated.
• Verify the auxiliary power supply for the charging circuit.
• Inspect the control board input circuit for hardware faults.
• Check the power unit for charging circuit failures.
• Replace the faulty charging contactor if defective.
• Replace damaged charging resistors or wiring as required.
• Replace the control board if the feedback input circuit has failed.
• Replace the power unit if the charging hardware is defective.
• Contact ABB technical support if the fault persists after hardware inspection.

Additional Information

The ABB ACS880 incorporates a charging (precharge) system that gradually charges the DC bus capacitors whenever the drive is powered on. This controlled charging process limits inrush current and protects the rectifier, capacitors, contactors, and other power electronic components.

The control unit continuously monitors a charging feedback signal to verify that the charging circuit is functioning correctly. If this signal is not received within the expected time, the drive assumes that the charging process has failed and generates Fault 5697.

Unlike a DC bus undervoltage or power supply fault, Fault 5697 specifically indicates that the control unit cannot confirm proper operation of the charging system because the required feedback signal is missing.

This fault is typically associated with the charging contactor, charging resistor, feedback wiring, control board input circuitry, or the power unit hardware.

Common Symptoms

• Drive trips with Fault 5697.
• Drive will not start.
• Fault appears during power-up.
• Charging sequence fails to complete.
• Main contactor does not engage after charging.
• DC bus charging is interrupted.
• Fault remains after reset.
• Charging contactor does not operate correctly.
• No visible external damage despite the fault.
• Fault may occur after replacing internal hardware.

Recommended Troubleshooting Sequence

1. Cycle power to the drive.
2. Inspect the charging system for proper operation.
3. Verify the charging contactor closes during startup.
4. Check the charging contactor coil and control voltage.
5. Inspect the charging resistor.
6. Verify the charging feedback signal.
7. Inspect the charging feedback wiring.
8. Ensure all internal connectors are securely connected.
9. Verify the auxiliary power supply.
10. Inspect the control board input circuit.
11. Inspect the power unit charging hardware.
12. Replace defective charging components if necessary.
13. Replace the control board if the feedback circuit has failed.
14. Replace the power unit if required.
15. Contact ABB technical support if the fault persists.

Charging Feedback Check Table

Check Point	Action
Power cycle	Restart the drive
Charging system	Verify proper operation
Charging contactor	Check operation during startup
Contactor coil	Verify control voltage and coil condition
Charging resistor	Inspect for damage or open circuit
Charging feedback signal	Verify signal reaches the control unit
Feedback wiring	Inspect for loose or damaged connections
Internal connectors	Ensure secure connections
Auxiliary power supply	Verify proper voltage
Control board	Inspect feedback input circuit
Power unit	Inspect charging hardware
PCB condition	Check for contamination or burn marks
ABB technical support	Contact if the fault remains after inspection

Preventive Maintenance Tips

• Inspect the charging contactor during scheduled maintenance.
• Verify charging resistor condition periodically.
• Inspect charging feedback wiring for secure connections.
• Keep internal connectors clean and properly seated.
• Protect the drive from electrical surges using appropriate protection devices.
• Maintain a clean, dry enclosure to prevent contamination.
• Verify stable auxiliary power for the charging system.
• Inspect control boards periodically for signs of overheating or aging.
• Use only ABB-approved replacement components.
• Record recurring charging feedback faults to assist long-term diagnostics.

Proper inspection of the charging circuit, verification of the charging feedback signal, routine maintenance of the charging contactor, resistor, control board, and power unit, and timely replacement of defective charging components will help prevent recurring 5697 Charging Feedback faults in ABB ACS880 drives, ensuring safe DC bus charging, reliable drive startup, and long-term protection of the drive's power electronics.