Micrologic X Control Unit Diagnostics and Maintenance

The Micrologic X control unit performs a high level of diagnostics in real time on Masterpact MTZ circuit breakers. They generate and store appropriate warnings, alarms, and messages to help the users with maintenance and power restoration.

These diagnostics:

  • Prevent interruption of the power supply to maintain continuity of operation, preserve assets from damage, and support the safety of personnel.

  • Reduce downtime resulting from an unexpected outage in the electrical distribution system by facilitating a restart as quickly as possible after a trip.

  • Keep devices in good operating condition and aid qualified personnel when repairs are required.

  • Build the history and traceability of all interventions to improve preventive maintenance and secure daily operation.

Prevention of Power Supply Interruptions

The Micrologic X control unit monitors the condition of the circuit breaker and generates information to help in scheduling periodic checks and, if needed, replacement of devices.

Most of the active mechanical and electrical components of the circuit breaker and the control unit are monitored. Warnings and alarms are issued when issues requiring the intervention of the maintenance staff are detected.

Maintenance recommendations are based on monitoring the operation and performance of the circuit breaker (such as number of operations, closing, and opening times). When threshold limits are reached or exceeded, alarms and warnings are issued to advise operators to plan maintenance.

The Micrologic X control unit monitors parameters to estimate circuit breaker aging (load profile, contact wear, and the end of life indicator for instance). Based on the these values, algorithms identify if maintenance or part replacement is needed.

NOTE: for further details please refer to Power Shutdown Prevention and Repair and Masterpact MTZ Services.

Restart After a Trip

The LEDs on the front of the Micrologic X control unit identify the tripping cause. Relevant information characterizing the fault can be retrieved using a smart phone or device via either Bluetooth technology or NFC or using Ecoreach software on a PC.

Warning and Alarm Displays

The Micrologic X control unit has a "Service" LED to indicate the circuit breaker condition. This LED, represented by a "wrench / spanner", has three states:

  • Unlit LED: the unit is in good working order.

  • Orange LED: non-urgent intervention is required (contact wear above 60% for example).

  • Red LED: alert message that requires immediate intervention (such as contact wear above 100% or an invalid control unit self test).

The messages processed by the Micrologic X control unit to monitor circuit breaker availability and maintenance operations are classified in three categories:

  • Maintenance assistance

  • Circuit breaker condition

  • Circuit breaker diagnostics

The associated warnings and alarms are displayed on the embedded HMI. The warnings are displayed with an orange backlight, the alarm with a red backlight.

When the Micrologic X control unit is not energized only the trip alarms with their associated messages remain accessible with a smart phone through NFC.

The various possibilities to display warnings, alarms and messages concerning the management of maintenance and the condition of the circuit breaker are summarized in the following table:


Trip Unit Energized

Trip Unit Not Energized


Display on embedded HMI Warning

Display on embedded HMI Alarm

Display on smart phone with Bluetooth technology

Ecoreach software USB connection

Display On FDM128

IFE/EIFE web pages

Display trip alarm on smartphone with NFC


Orange Backlight


Red Backlight

Prevent Power Shutdown with Conditional Checks

Monitored Functions and Logs for Circuit Breaker Operation

Elect. Closing Function

Elect. Opening Function

Tripping Function

  • XF coil circuit continuity

  • MCH charging time

  • “Time stamped” closing log

  • MCH counter

  • Alarm fail closing order

  • MX coil circuit continuity

  • MN coil circuit continuity

  • Opening counter

  • “Time stamped” opening log (Electrical/ mechanical)

  • Alarm fail opening order

  • Tripping chain continuity (Ready LED)

  • Trip counter (SDE)

  • Time stamped event log

Monitored Functions & Logs Fault Detection on Micrologic X

External Sensors Disconnection

Micrologic X Control Unit Problem

External Communication Problem

  • Internal Current Transformers [T]

  • External Neutral CT

  • Vigi Sensor

  • ASIC over temp [T]

  • ASIC problem [T]

  • Error reading perform / Sensor rating

  • Internal battery

  • Trip solenoid is not connected, default is to trip the circuit breaker

  • Bluetooth error

  • Ethernet Error communication (IFE)

  • IO module

Repairing a Device

The Micrologic X control unit includes dedicated functions for maintenance assistance.

The following information can be retrieved:

  • Serial number and features of the circuit breaker.

  • Optional accessories installed on the circuit breaker.

  • References for spare parts and replacement accessories.

  • Type of problem encountered with maintenance assistance information.

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