Troubleshooting: Mechanical Control Operations

The blue fault-trip reset button is popped out.

The blue fault-trip reset button has not been reset.

• Clear the fault.

• Push the blue fault-trip reset button.

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Circuit breaker is padlocked or keylocked in the open position.

Unlock the circuit breaker.

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Circuit breaker is interlocked mechanically in a mechanical interlocking system.

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

• Modify the situation to release the interlock.

The closing spring and ready-to-close indicator shows that the mechanism is discharged.

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Stored energy mechanism is not charged.

• Charge the mechanism manually.

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

The closing spring and ready-to-close indicator shows that the mechanism is charged but the circuit breaker is not ready to close.

MX opening voltage release is permanently powered.

As there is an opening order, determine the origin of the order. The order must be canceled before the circuit breaker can be closed.

MN undervoltage release is not powered due to an opening order.

As there is an opening order, determine the origin of the order. The order must be canceled before the circuit breaker can be closed.

MN undervoltage release is not powered due to insufficient voltage power supply.

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

If the problem persists, replace the MN undervoltage release.

Recurring undervoltage trip.

The measured voltage remains at 0 V.

Set the undervoltage behavior parameter, Vmin behavior, to Force to Off when CB is open. For more information, refer to DOCA0265•• MasterPacT MTZ - MicroLogic Active Control Unit - User Guide in Related Documents at the beginning of this guide.

The position release button on the chassis of the drawout circuit breaker is pushed in.

Circuit breaker is not correctly connected.

Terminate racking in (connection) of the circuit breaker, making sure that it is fully inserted in the chassis, to the connected position. Check that the position release button is popped out.

Operating mechanism incident or welded contacts.

Contact your Schneider Electric Services representative.