Monitoring the Contact Wear

Presentation

The pole contacts undergo wear due to the number of operating cycles with current and interrupted current during short circuits. It is recommended to check them at periodic intervals to decide whether the contacts must be changed or not. In order to reduce systematic visual inspections of the contacts and the arc chute, the contact wear estimate helps with the planning of visual inspections based on the estimated wear (from 0% - new contact - to 100% - totally worn contact).

Operating Principle

The contact wear increases every time the circuit breaker interrupts the circuit with or without current.

When the MicroLogic Active control unit contact wear algorithm calculates a value which is above one of the predefined thresholds (60%, 95%, and 100%) an event is generated with an orange or red pop-up screen and corresponding event message.

Data Availability

Contact wear monitoring data is available:

On the MicroLogic Active display screen, from the tree navigation menu, at Maintenance > Health > Contact wear.
With the IEEE 802.15.4 wireless communication network for MicroLogic Active AP/EP control units.

Predefined Events

The function generates the following events:

Code	Event	History	Severity
0x1440 (5184)	Contact wear > 60%. Check contacts.	Diagnostic	Medium
0x1441 (5185)	Contact wear > 95%. Plan circuit breaker replacement.	Diagnostic	Medium
0x1442 (5186)	Contact wear > 100%. Replace circuit breaker.	Diagnostic	High

Recommended Actions

Code	Event	Recommended actions
0x1440 (5184)	Contact wear > 60%. Check contacts.	Inspect visually the arc chute and main contacts at the next scheduled maintenance.
0x1441 (5185)	Contact wear > 95%. Plan circuit breaker replacement.	Plan to replace the circuit breaker.
0x1442 (5186)	Contact wear > 100%. Replace circuit breaker.	Replace the circuit breaker.

Contact Schneider Electric Support or your Schneider Electric Services representative for more information about who can carry out the recommended actions.