How to Maintain MicroLogic Control Unit

Functions

The control unit permanently monitors the electrical network and generates trip orders when electrical faults are detected.

Electronic component qualification data is usually quoted for a 10-year lifetime by the component suppliers according to the device mission profile. The control unit can operate more than 10 years, depending on the operating environmental conditions (for example, temperature, humidity, vibrations, mechanical shocks, corrosive atmosphere).

Schneider Electric recommends that the field service representative replaces the MicroLogic control unit and associated optional M2C modules every 15 years. Each time the MicroLogic control unit is replaced, the performer, the rating plug, and the sensor plug must be replaced by the Schneider Electric field service representative.

Degradation Factors

The factors which can cause degradation of the control unit and electronic components are the following:

Shocks
Vibration
Humidity
High ambient temperature
Corrosive atmosphere

Potential Hazards

Performing regular maintenance on the control unit can help to avoid the potential hazards and consequences listed in the following table.

Hazard	Consequence
Hazard	Personal injury	Equipment damage
High short-circuit current and no tripping order	–	Degradation of the breaking unit

Preventive Action

The following table lists the preventive maintenance procedures to be performed to maintain the control unit.

Maintenance program	Preventive action	Procedure
Basic end-user preventive maintenance	Check the general condition of the device.	Device NII_1_1
Standard end-user preventive maintenance	Check overcurrent protection.	Device NIII_2_1
Manufacturer preventive maintenance	Perform aging diagnostic to evaluate when to preventively replace the MicroLogic control unit.	Contact your Schneider Electric field service representative.

For more information, refer to Preventive Maintenance Programs.