Overview
The LE3400U44X is a Schneider STR Series trip unit for PowerPacT L air circuit breakers, rated 6.3 A with LSIG protection and a built-in Micrologic ammeter. It covers breaker frames from 125 A to 400 A. Schneider lists this unit as active production, so it remains available for new builds and replacement without a last-time-buy deadline.
Sizing and selection
The 6.3 A rating sets the LE3400U44X apart from the LE3400U43X, which is rated 5.3 A. Choose the LE3400U44X when the load or coordination study calls for the higher 6.3 A setting; the LE3400U43X fits when the design specifies 5.3 A.