The Schneider Electric LE3600U53X is an electronic trip unit for the PowerPact L molded-case circuit breaker family, configured with Micrologic 5.3E LSI protection for 200A to 600A frames, 3-pole.
This part is officially obsolete per the manufacturer's lifecycle record.
The Micrologic 5.3E LSI trip unit provides Long-time, Short-time, and Instantaneous protection curves — the LSI designation means it omits ground-fault (LG) protection, so it is sized for feeders or main breakers where ground-fault coordination is handled downstream or by a separate relay. Rated for 200A to 600A frames, this unit fits the PowerPact L breaker line — the trip unit plugs into the breaker's cradle and is field-interchangeable without removing the breaker from the panel.