Troubleshooting and Solutions

Circuit breaker cannot be closed locally or remotely.

Circuit breaker padlocked or keylocked in the "open" position.

• Disable the locking function.

Circuit breaker interlocked mechanically in a source changeover system.

• Check the position of the other circuit breaker in the changeover system.

• Modify the situation to release the interlock.

Circuit breaker not completely connected.

Terminate racking in (connection) of the circuit breaker.

The reset button signalling a fault trip has not been reset.

• Clear the fault.

• Push the reset button on the front of the circuit breaker.

Stored energy mechanism not charged.

• Charge the mechanism manually.

• If it is equipped with an MCH gear motor, check the supply of power to the motor. If the problem persists, replace the gear motor (MCH).

MX opening voltage release permanently supplied with power.

There is an opening order. Determine the origin of the order. The order must be cancelled before the circuit breaker can be closed

MN undervoltage release not supplied with power.

• There is an opening order. Determine the origin of the order.

• Check the voltage and the supply circuit (U > 0.85 Un).

If the problem persists, replace the MN undervoltage release.

XF closing voltage release continuously supplied with power, but circuit breaker not "ready to close" (XF not wired in series with PF contact).

Cut the supply of power to the XF closing voltage release, then send the closing order again via the XF, but only if the circuit breaker is "ready to close".

Permanent trip order in the presence of a MicroLogic P or H control unit with minimum voltage and minimum frequency protection in Trip mode and the control unit powered.

Disable these protection functions on the MicroLogic P or H control unit.

Circuit breaker cannot be closed remotely but can be opened locally using the closing pushbutton.

Closing order not executed by the XF closing voltage release.

Check the voltage and the supply circuit (0.85 - 1.1 Un).

If the problem persists, replace the XF closing voltage release.

Unexpected tripping without activation of the reset button signalling a fault trip.

MN undervoltage release supply voltage too low.

Check the voltage and the supply circuit (U > 0.85 Un).

Load-shedding order sent to the MX opening voltage release by another device.

Check the overall load on the distribution system.

If necessary, modify the settings of devices in the installation.

Unnecessary opening order from the MX opening voltage release.

Determine the origin of the order.

Unexpected tripping with activation of the reset button signalling a fault trip.

A fault is present:

• Overload

• Earth fault

• Short-circuit detected by the control unit.

• Determine and clear the causes of the fault.

• Check the condition of the circuit breaker before putting it back into service.

Instantaneous opening after each attempt to close the circuit breaker with activation of the reset button signalling a fault trip.

Thermal memory.

• See the user manual of the control unit.

• Press the reset button.

Transient overcurrent when closing.

• Modify the distribution system or the control unit settings.

• Check the condition of the circuit breaker before putting it back into service.

• Press the reset button.

Closing on a short-circuit.

• Clear the fault.

• Check the condition of the circuit breaker before putting it back into service.

• Press the reset button.

Circuit breaker cannot be opened remotely, but can be opened locally.

Opening order not executed by the MX opening voltage release.

Check the voltage and the supply circuit (0.7 - 1.1 Un).

If the problem persists, replace the MX opening voltage release.

Opening order not executed by the MN undervoltage release.

Drop in voltage insufficient or residual voltage (> 0.35 Un) across the terminals of the undervoltage release.

If the problem persists, replace the MN undervoltage release.

Circuit breaker cannot be opened locally.

Operating mechanism malfunction or welded contacts.

Contact a Schneider Electric service centre.

Circuit breaker cannot be reset locally but not remotely.

Insufficient supply voltage for the MCH gear motor.

Check the voltage and the supply circuit (0.7 - 1.1 Un).

If the problem persists, replace the MCH gear motor.

Nuisance tripping of the circuit breaker with activation of the reset button signalling a fault trip.

Reset button not pushed-in completely.

Push the button in completely.

Impossible to insert the crank in connected, test or disconnected position.

A padlock or keylock is present on the chassis or a door interlock is present.

Disable the locking function.

Impossible to turn the crank.

The reset button has not been pressed.

Press the reset button.

Circuit breaker cannot be removed from chassis.

Circuit breaker not in disconnected position.

Turn the crank until the circuit breaker is in disconnected position and the reset button out.

The rails are not completely out.

Pull the rails out all the way.

Circuit breaker cannot be connected (racked in).

Chassis/circuit breaker mismatch protection.

Check that the chassis corresponds with the circuit breaker.

The safety shutters are locked.

Remove the locks.

The disconnecting contact clusters are incorrectly positioned.

Reposition the clusters.

Chassis locked in disconnected position.

Disable the chassis locking function.

The reset button has not been pressed, preventing the rotation of the crank.

Press the reset button.

The circuit breaker has not been sufficiently inserted in the chassis.

Insert the circuit breaker completely so that it is engaged in the racking mechanism.

Circuit breaker cannot be locked in disconnected position.

The circuit breaker is not in the right position.

Check the circuit breaker position by making sure the reset button is out.

The crank is still in the chassis.

Remove the crank and store it.

Circuit breaker cannot be locked in connected, test or disconnected position.

Check that locking in any position is enabled.

Contact a Schneider Electric service centre.

The circuit breaker is not in the right position.

Check the circuit breaker position by making sure the reset button is out.

The crank is still in the chassis.

Remove the crank and store it.

The crank cannot be inserted to connect or disconnect the circuit breaker.

The rails are not completely in.

Push the rails all the way in.

The right-hand rail (chassis alone) or the circuit breaker cannot be drawn out.

The crank is still in the chassis.

Remove the crank and store it.