Automatic trip curve testing on breakers with a non-communicating Micrologic trip unit

Thermal memory is a function that models temperature of the cables that are connected to the circuit breaker after a tripping event. This function causes the circuit breaker to trip faster than the published time-current curve, if the wiring had not cooled. Under normal conditions, 15 minutes delay is required following a device tripping to allow the system to cool before returning to normal functionality. The reset thermal memory function inhibits thermal memory, thus overriding the 15 minutes delay and allowing for multiple consecutive primary injection tests.

NOTE: The table below shows that non-communicating Micrologics cannot inhibit the thermal memory, and therefore you must wait 15 minutes between testing.

Inhibit ground fault protection: This function allows a single phase primary injected test current to be applied without causing the circuit breaker to trip on ground fault. It is used when testing the LSI protection functions of the circuit breaker.

NOTE: Ground fault protection option is available when connected to MicroLogic 6.0 A, 6.0 E, 6.0 P, or 6.0 H trip unit.

Released for: Schneider Electric Ireland