1. The circuit breaker is in the closed position;

2. The handle is not fully inserted into the push‑in hole on the chassis vehicle.

3. The actuating mechanism has not fully reached the experimental position, preventing the chassis’s locking plate from disengaging from the cabinet body.

1. The circuit breaker is in the unenergized state.

2. The circuit breaker is already in the closed position.

3. A closing‑lockout coil has been selected; the auxiliary power supply is not connected.

4. Inaccurate secondary circuits, or damage to secondary components such as auxiliary switches and closing release devices.

5. The handcart-type circuit breaker has not been fully inserted into the working position or the test position.

6. After installation in conjunction with the cabinet, the circuit breaker frame becomes deformed.

1. The circuit breaker is in the open position.

2. The secondary circuit is inaccurate, or secondary components such as auxiliary switches and trip release mechanisms are damaged.

3. After installation in conjunction with the cabinet, deformation of the circuit breaker frame causes the closing mechanism to reach an over‑dead‑center position.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. Analyze the load and grid operating conditions;

3. If an overload is confirmed, immediately identify and rectify the fault.

4. If the actual operating current does not match the long-time delay trip current, adjust the long-time delay trip setting to reflect the actual operating current, ensuring proper protective coordination.

5. Press the reset button to reclose the circuit breaker.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. If a short circuit is confirmed, promptly locate and rectify the fault.

3. Check the setpoints of the smart controller;

4. Inspect the circuit breaker to ensure it is in good condition and confirm that it can be closed and operated.

5. Press the reset button to reclose the circuit breaker.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. If a short circuit is confirmed, promptly locate and rectify the fault.

3. If no ground fault is detected, verify that the ground-fault current setting is appropriate and matches the actual protection requirements; if the setting is incorrect, adjust the ground-fault current setting accordingly.

4. Press the reset button to reclose the circuit breaker.

1. Check whether the supply voltage is below 70% of Us;

2. Check whether the undervoltage release and the control unit are malfunctioning.

1. Has the undervoltage release been energized?

2. Check whether the supply voltage is below 70% of Us;

3. Check whether the undervoltage release and the control unit are malfunctioning; if a fault is confirmed, replace the undervoltage release.

1. Verify that the motor control power supply is energized and that the voltage is at least 85% of the rated voltage (Us).

2. Inspect the motor’s energy-storage mechanism for any malfunctions.

1. Verify that the closing solenoid’s supply voltage is ≥85% of Us.

2. If the closing solenoid is defective and fails to engage, it should be replaced.

Trip immediately

Time-delay tripping

1. If a short-circuit current is present in the circuit during closing, the fault should be located and eliminated.

2. Check whether there is an overcurrent in the circuit, and locate and eliminate any faults.

3. The circuit breaker mechanism shall be inspected to ensure it is in good working condition;

4. Verify that the setpoints of the smart controller are appropriate; if not, recalibrate them.

5. Press the reset button to reclose the circuit breaker.

l Cannot trip the circuit breaker remotely.

The circuit breaker cannot be opened by the trip button.

1. Verify that the shunt trip circuit connections are secure and inspect the shunt trip for any faults; if a fault is confirmed, replace the shunt trip.

2. Inspect the operating mechanism for any mechanical malfunctions.

1. Verify that the control power supply voltage of the electric energy storage device is ≥85% of Us, and check for any issues with the circuit connections.

2. Check the motor for any issues;

3. Energy storage system failure.

The smart controller is not powered on.

l The auxiliary power input voltage is abnormal.

The secondary output voltage of the base transformer is abnormal.

The connection between the secondary output of the base transformer and the controller is unreliable.

1. Verify that the smart controller’s power supply is properly connected.

2. Disconnect the power supply to the smart controller, then reconnect it. If the fault persists, the controller may be defective and should be replaced.

The communication cable is not reliably connected to the circuit breaker terminal.

l The A and B ends of the communication line are connected in reverse.

l The communication distance and connection method have issues and do not meet the requirements.

l There is a problem with the circuit breaker’s communication address configuration.

1. Verify that the communication cable is securely connected to the circuit breaker terminals and that there are no wiring errors.

2. Check whether the A and B ends of the communication cable are connected in reverse; if so, correct the wiring.

3. Verify that the communication distance and wiring configuration meet the specified requirements.

4. Verify that the circuit breaker’s communication address is configured correctly and does not conflict with other devices.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. Analyze the load and grid operating conditions;

3. If an overload is confirmed, immediately identify and rectify the fault.

4. If the actual operating current does not match the long-time delay setting current, adjust the long-time delay setting current to reflect the actual operating current, ensuring proper protective coordination.

5. Press the reset button to reclose the circuit breaker.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. If a short circuit is confirmed, immediately locate and eliminate the fault.

3. Check the setpoints of the smart controller;

4. Inspect the circuit breaker to ensure it is in good condition and confirm that it can be closed and operated.

5. Press the reset button to reclose the circuit breaker.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. If a short circuit is confirmed, immediately locate and eliminate the fault.

3. If no ground fault is detected, verify that the ground-fault current setting is appropriate and matches the actual protection requirements; if the setting is incorrect, adjust the ground-fault current setting accordingly.

4. Press the reset button to reclose the circuit breaker.

1. Check whether the supply voltage is below 70% of Us;

2. Check whether the undervoltage release and the control unit are malfunctioning.

1. Has the undervoltage release been energized?

2. Check whether the supply voltage is below 85% of Us;

3. Check whether the undervoltage release and the control unit are malfunctioning; if a fault is confirmed, replace the undervoltage release.

1. Verify that the motor control power supply is connected and that the voltage is at least 85% of the rated voltage (Us).

2. Inspect the motor’s energy-storage mechanism for any malfunctions.

1. Verify that the closing solenoid’s supply voltage is ≥85% of Us.

2. If the closing solenoid is malfunctioning and fails to engage, it should be replaced.

1. If a short-circuit current is present in the circuit during closing, locate and eliminate the fault.

2. Check whether there is an overload current in the circuit, and locate and eliminate any faults.

3. The circuit breaker mechanism shall be inspected to ensure it is in good condition;

4. Verify that the setpoints of the intelligent controller are appropriate; if not, reset them accordingly.

5. Press the reset button to reclose the circuit breaker.

1. Verify that the shunt trip circuit connections are secure and inspect the shunt trip for any faults; if a fault is confirmed, replace the shunt trip.

2. Inspect the operating mechanism for any mechanical malfunctions.

3. Is the voltage of the shunt trip device below 85%?

1. Verify that the control power supply voltage of the electric energy storage device is ≥85% of Us, and check for any issues with the circuit connections.

2. Check the motor for any issues;

3. Energy storage system failure.

l The latch was not held down l The lever was not pulled out

The circuit breaker has not fully reached the “open” position.

The smart controller is not powered on.

The auxiliary power input voltage is abnormal.

The secondary output voltage of the base transformer is abnormal.

The secondary output of the base transformer is not reliably connected to the controller.

1. Verify that the smart controller’s power supply is properly connected.

2. Disconnect the power supply to the smart controller, then reconnect it. If the fault persists, the controller may be defective and should be replaced.

The communication cable is not reliably connected to the circuit breaker terminal.

The polarity of communication lines A and B is reversed.

The communication distance and connection method have issues and do not meet the requirements.

l There is a problem with the circuit breaker’s communication address configuration. l The communication parameter settings are mismatched.

1. Verify that the communication cable is securely connected to the circuit breaker terminals and that there are no wiring errors.

2. Check whether the A and B ends of the communication line are connected in reverse; if so, correct the wiring.

3. Verify that the communication distance and wiring configuration meet the specified requirements.

4. Verify that the circuit breaker’s communication address is configured correctly and does not conflict with other devices.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. Analyze the load and grid operating conditions;

3. If an overload is confirmed, immediately identify and rectify the fault.

4. If the actual operating current does not match the long-time delay setting current, adjust the long-time delay setting current to reflect the actual operating current, ensuring proper protective coordination.

5. Press the reset button to reclose the circuit breaker.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. If a short circuit is confirmed, promptly locate and rectify the fault.

3. Check the setpoints of the smart controller;

4. Inspect the circuit breaker to ensure it is in good condition and verify that it can be closed and operated.

5. Press the reset button to reclose the circuit breaker.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. If a short circuit is confirmed, promptly locate and rectify the fault.

3. If no ground fault is detected, verify that the ground-fault current setting is appropriate and matches the actual protection requirements; if the setting is incorrect, adjust the ground-fault current setting accordingly.

4. Press the reset button to reclose the circuit breaker.

1. Check whether the supply voltage is below 70% of Us;

2. Check whether the undervoltage release and the control unit are malfunctioning.

1. Has the undervoltage release been energized?

2. Check whether the supply voltage is below 85% of Us;

3. Check whether the undervoltage release and the control unit are malfunctioning; if a fault is confirmed, replace the undervoltage release.

1. Verify that the motor control power supply is connected and that the voltage is at least 85% of the rated voltage (Us).

2. Inspect the motor’s energy-storage mechanism for any malfunctions.

1. Verify that the closing solenoid’s supply voltage is ≥85% of Us.

2. If the closing solenoid is defective and fails to engage, it should be replaced.

Trip immediately

Time-delay tripping

1. If a short-circuit current is present in the circuit during closing, locate and eliminate the fault.

2. Check whether there is an overload current in the circuit, and locate and eliminate any faults.

3. The circuit breaker mechanism shall be inspected to ensure it is in good condition;

4. Verify that the setpoints of the intelligent controller are appropriate; if not, reset them accordingly.

5. Press the reset button to reclose the circuit breaker.

l cannot trip the circuit breaker remotely.

The circuit breaker cannot be opened by the trip button.

1. Verify that the shunt trip circuit connections are secure and inspect the shunt trip for any faults; if a fault is confirmed, replace the shunt trip.

2. Inspect the operating mechanism for any mechanical malfunctions.

3. Is the voltage of the shunt trip device below 85%?

l cannot be manually energized.

l cannot store energy electrically

1. Verify that the control power supply voltage of the electric energy storage device is ≥85% of Us, and check for any issues with the circuit connections.

2. Check the motor for any issues;

3. Energy storage system failure.

l The latch was not held down l The joystick was not pulled out

The circuit breaker has not fully reached the “open” position.

The smart controller is not powered on.

The auxiliary power input voltage is abnormal.

The secondary output voltage of the base transformer is abnormal.

The connection between the secondary output of the base transformer and the controller is unreliable.

1. Verify that the smart controller’s power supply is properly connected.

2. Disconnect the power supply to the smart controller, then reconnect it. If the fault persists, the controller may be defective and should be replaced.

The communication cable is not reliably connected to the circuit breaker terminal.

The polarity of communication lines A and B is reversed.

The communication distance and connection method have issues and do not meet the requirements.

l There is a problem with the circuit breaker’s communication address configuration.

l Communication parameter settings do not match

1. Verify that the communication cable is securely connected to the circuit breaker terminals and that there are no wiring errors.

2. Verify that the A and B ends of the communication cable are not reversed; if they are, correct the wiring.

3. Verify that the communication distance and wiring configuration meet the specified requirements.

4. Verify that the circuit breaker’s communication address is configured correctly and does not conflict with other devices.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. Analyze the load and grid operating conditions;

3. If an overload is confirmed, immediately identify and rectify the fault.

4. If the actual operating current does not match the long-time delay setting current, adjust the long-time delay setting current to reflect the actual operating current, ensuring proper protective coordination.

5. Press the reset button to reclose the circuit breaker.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. If a short circuit is confirmed, promptly locate and rectify the fault.

3. Check the setpoints of the smart controller;

4. Inspect the circuit breaker to ensure it is in good condition and confirm that it can be closed and operated.

5. Press the reset button to reclose the circuit breaker.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. If a short circuit is confirmed, promptly locate and rectify the fault.

3. If no ground fault is detected, verify that the ground-fault current setting is appropriate and matches the actual protection requirements; if the setting is incorrect, adjust the ground-fault current setting accordingly.

4. Press the reset button to reclose the circuit breaker.

1. Check whether the supply voltage is below 70% of Us;

2. Check whether the undervoltage release and the control unit are malfunctioning.

1. Has the undervoltage release been energized?

2. Check whether the supply voltage is below 85% of Us;

3. Check whether the undervoltage release and the control unit are malfunctioning; if a fault is confirmed, replace the undervoltage release.

1. Verify that the motor control power supply is connected and that the voltage is at least 85% of the rated voltage (Us).

2. Inspect the motor’s energy-storage mechanism for any malfunctions.

1. Verify that the closing solenoid’s supply voltage is ≥85% of Us.

2. If the closing solenoid is defective and fails to engage, it should be replaced.

1. If a short-circuit current is present in the circuit during closing, locate and eliminate the fault.

2. Check whether there is an overcurrent in the circuit, and locate and eliminate any faults.

3. The circuit breaker mechanism shall be inspected to ensure it is in good condition;

4. Verify that the setpoints of the intelligent controller are appropriate; if not, reset them accordingly. 5. Press the reset button to reclose the circuit breaker.

l cannot trip the circuit breaker remotely.

The circuit breaker cannot be opened by the trip button.

1. Verify that the shunt trip circuit connections are secure and inspect the shunt trip for any faults; if a fault is confirmed, replace the shunt trip.

2. Inspect the operating mechanism for any mechanical malfunctions.

3. Is the voltage of the shunt trip device below 85%?

l cannot be manually energized.

L cannot store energy electrically.

1. Verify that the control power supply voltage of the electric energy storage device is ≥85% of Us, and inspect the circuit connections for any issues.

2. Check the motor for any issues;

3. Energy storage system failure.

lDid not hold the latch

The joystick has not been pulled out.

The circuit breaker has not fully reached the “open” position.

The smart controller is not powered on.

The auxiliary power input voltage is abnormal.

The secondary output voltage of the base transformer is abnormal.

The secondary output of the base transformer is not reliably connected to the controller.

1. Verify that the smart controller’s power supply is properly connected.

2. Disconnect the power supply to the smart controller, then reconnect it. If the fault persists, the controller may be defective and should be replaced.

The communication cable is not reliably connected to the circuit breaker terminal.

The polarity of communication lines A and B is reversed.

The communication distance and connection method have issues and do not meet the requirements.

l There is a problem with the circuit breaker’s communication address configuration.

l Communication parameter settings do not match

1. Verify that the communication cable is securely connected to the circuit breaker terminals and that there are no wiring errors.

2. Verify that the A and B ends of the communication cable are not reversed; if they are, correct the wiring.

3. Verify that the communication distance and wiring configuration meet the specified requirements.

4. Verify that the circuit breaker’s communication address is configured correctly and does not conflict with other devices.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. Analyze the load and grid operating conditions;

3. If an overload is confirmed, immediately identify and rectify the fault.

4. If the actual operating current does not match the long-time delay setting current, adjust the long-time delay setting current to reflect the actual operating current, ensuring proper protective coordination.

5. Press the reset button to reclose the circuit breaker.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. If a short circuit is confirmed, immediately locate and eliminate the fault.

3. Check the setpoints of the smart controller;

4. Inspect the circuit breaker to ensure it is in good condition and confirm that it can be closed and operated.

5. Press the reset button to reclose the circuit breaker.

1. On the intelligent controller, verify the breaking current value and the operating time.

2. If a short circuit is confirmed, immediately locate and eliminate the fault.

3. If no ground fault is detected, verify that the ground-fault current setting is appropriate and matches the actual protection requirements; if the setting is incorrect, adjust the ground-fault current setting accordingly.

4. Press the reset button to reclose the circuit breaker.

1. Check whether the supply voltage is below 70% of Us;

2. Check whether the undervoltage release and the control unit are malfunctioning.

1. Has the undervoltage release been energized?

2. Check whether the supply voltage is below 85% of Us;

3. Check whether the undervoltage release and the control unit are malfunctioning; if a fault is confirmed, replace the undervoltage release.

1. Verify that the motor control power supply is connected and that the voltage is at least 85% of the rated voltage (Us).

2. Inspect the motor’s energy‑storage mechanism for any malfunctions.

1. Verify that the closing solenoid’s supply voltage is ≥85% of Us.

2. If the closing solenoid is defective and fails to engage, it should be replaced.

1. If a short-circuit current is present in the circuit during closing, locate and eliminate the fault.

2. Check whether there is an overload current in the circuit, and locate and eliminate any faults.

3. The circuit breaker mechanism shall be inspected to ensure it is in good condition;

4. Verify that the setpoints of the intelligent controller are appropriate; if not, reset them accordingly.

5. Press the reset button to reclose the circuit breaker.

1. Verify that the shunt trip circuit connections are secure and inspect the shunt trip for any faults; if a fault is confirmed, replace the shunt trip.

2. Inspect the operating mechanism for any mechanical malfunctions.

3. Is the shunt trip coil voltage below 85%?

1. Verify that the control power supply voltage of the electric energy storage device is ≥85% of Us, and check for any issues with the circuit connections.

2. Check the motor for any issues; 3. Fault in the energy-storage mechanism.

The smart controller is not powered on.

The auxiliary power input voltage is abnormal.

The secondary output voltage of the base transformer is abnormal.

The secondary output of the base transformer is not reliably connected to the controller.

1. Verify that the smart controller’s power supply is properly connected.

2. Disconnect the power supply to the smart controller, then reconnect it. If the fault persists, the controller may be defective and should be replaced.

The communication cable is not reliably connected to the circuit breaker terminal.

l The A and B ends of the communication line are connected in reverse. l There are issues with the communication distance and connection method that do not meet the requirements.

l There is a problem with the circuit breaker’s communication address configuration.

l Communication parameter settings do not match

1. Verify that the communication cable is securely connected to the circuit breaker terminals and that there are no wiring errors.

2. Check whether the A and B ends of the communication cable are connected in reverse; if so, correct the wiring.

3. Verify that the communication distance and wiring configuration meet the specified requirements.

4. Verify that the circuit breaker’s communication address is configured correctly and does not conflict with other devices.

Technical issue

Possible causes

Inspection and Troubleshooting Methods

Circuit breaker tripped (reset button popped out, fault indicator light on)

● Overload long-time delay trip (indicated by the smart controller as an overload long-time delay fault)

1. Verify the breaking current value and operating time on the intelligent controller.

2. Analyze the load and grid operating conditions;

3. If an overload trip is confirmed, promptly identify the cause of the overload and rectify the fault.

4. If the actual operating current does not match the long-time delay trip current, adjust the long-time delay trip current setting Ir1 according to the actual operating current.

5. Press the reset button to reclose the circuit breaker.

Short-circuit fault tripping (the smart controller indicates a short-time delay or instantaneous fault)

1. Verify the breaking current value and operating time on the intelligent controller.

2. If a short-circuit trip is confirmed, the cause of the fault must be promptly identified and the short-circuit fault eliminated.

3. Check the setpoints of Ir2 and Ir3 on the smart controller;

4. Inspect the circuit breaker to ensure it is in good condition and confirm that it can be closed and operated.

5. Press the reset button to reclose the circuit breaker.

Ground fault tripping (indicated as a ground fault by the smart controller)

1. Verify the breaking current value and operating time on the intelligent controller.

2. If a ground fault is confirmed, the cause must be promptly identified and the fault eliminated.

3. If no ground fault is confirmed, verify that the ground-fault current setting is appropriate and matches the actual protection requirements. If the setting is incorrect, adjust the ground-fault current setting accordingly.

4. Press the reset button to reclose the circuit breaker.

● Undervoltage release tripping

1. Check whether the supply voltage is below 70% of Ue;

2. Check whether the undervoltage release is malfunctioning.

● Shunt trip operation

Check whether any erroneous commands have been issued in the control circuit.

The circuit breaker cannot be closed.

● The undervoltage release has not operated.

1. Has the undervoltage release been energized?

2. Check whether the supply voltage is below 85% of Ue;

3. Check whether the undervoltage release is malfunctioning; if confirmed, replace the undervoltage release.

The reset button does not reset when in the pop-up state.

Press the reset button to reclose the circuit breaker.

The drawer-type circuit breaker has not been fully pushed into place.

Slide the drawer-type circuit breaker into place (it will be locked in either the “ON” or “TEST” position).

● Poor contact in the secondary circuit of a drawer-type circuit breaker

Inspect the secondary circuit contacts and eliminate any issues.

● Circuit breaker not energized

1. Verify that the control power supply of the electric operating mechanism is energized and that the voltage is ≥85% of Us.

2. Check whether the electric operating mechanism has any faults.

Mechanical interlocking operation: the circuit breaker is “locked out.”

Check whether the circuit breaker’s mechanical interlock is functioning properly.

Closing release mechanism issue

1. Verify that the control supply voltage of the closing release is ≥85% of Us.

2. If the closing release is faulty, replace the closing release.

The circuit breaker trips after closing.

Instantaneous trip, time-delayed trip

1. If a short-circuit current is present in the circuit during closing, the cause of the fault should be identified and rectified.

2. Check whether there is an overcurrent in the circuit, identify the cause of the fault, and eliminate it.

3. The circuit breaker mechanism shall be inspected to ensure it is in good condition;

4. Verify that the setpoints of the intelligent controller are appropriate; if not, adjust the setpoints accordingly.

5. Press the reset button to reclose the circuit breaker.

4

The circuit breaker cannot trip.

● The circuit breaker cannot be opened by electric operation; ● The circuit breaker cannot be manually opened using the trip button.

1. Verify that the auxiliary trip unit circuit connections are secure.

2. Inspect the shunt trip unit for faults; if a fault is confirmed, replace the shunt trip unit.

3. Inspect the circuit breaker mechanism for any mechanical faults;

4. The control supply voltage of the shunt trip release shall be ≥70% of Us.

The circuit breaker cannot store energy.

● Cannot store energy manually; cannot store energy electrically.

1. Verify that the control power supply voltage of the electric operating mechanism is ≥85% of Us.

2. Check the control power supply connection of the electric operating mechanism for any faults.

3. Inspect the motor of the electric operating mechanism for any faults.

4. Inspect the mechanical transmission mechanism of the electric operating mechanism for any malfunctions.

5. Inspect the operating handle, ratchet, pawl, and stop components.

A drawer-type circuit breaker cannot be withdrawn when it is in the “open” position.

The latch‑type circuit breaker was not held in place and did not fully reach the “open” position.

Press and hold the lock button; then fully swing the circuit breaker to the “OFF” position.

The drawer-type circuit breaker cannot be rocked into the “connected” position.

● Foreign objects have fallen into the drawer housing, jamming the ratchet mechanism; the ratchet mechanism’s gears are damaged.

Inspect the drawer base for any foreign objects; if present, remove them promptly. Also, check that the gears or rack inside the drawer base are in good condition.

The smart controller’s screen is blank.

● The smart controller is not connected to the auxiliary power supply; ● The input voltage of the smart controller’s auxiliary power supply is abnormal; ● The connection circuit for the smart controller’s auxiliary power supply inside the circuit breaker is unreliable.

Check that the auxiliary power supply connection of the smart controller is secure; verify that the auxiliary power supply voltage is within the normal range.

Communication is abnormal.

● The connection between the communication cable and the circuit breaker terminal is unreliable; the A and B ends of the communication cable are reversed. ● There is an issue with the circuit breaker’s communication address configuration. ● The communication parameters are mismatched.

1. Verify that the communication cable is securely connected to the circuit breaker terminals and that there are no wiring errors.

2. Check whether the communication lines A and B are connected in reverse; if so, correct the wiring.

3. Verify that the communication distance and connection method meet the specified requirements.

4. Verify that the circuit breaker’s communication address and other parameter settings are correct and do not conflict.