The Schneider Electric LA9FH4H4G is a mechanical interlock accessory from the TeSys F series, designed to physically prevent two or more contactors from closing simultaneously. This part specifically handles a three-contactor vertical stack, a common arrangement in reversing or star-delta motor starter panels where simultaneous closure would create a phase-to-phase short. It interlocks bottom-position contactors in the LC1F185 through LC1F225 range (3- or 4-pole) and CR1F185 through CR1F225, with top and middle positions accepting the larger LC1F265 through LC1F330 and CR1F265 through CR1F330 frames. That means one LA9FH4H4G covers a mixed-size stack — smaller contactors on the bottom, larger ones above — which is exactly what a typical two-speed or reversing motor starter needs.
Sourcing reality — obsolete part
The LA9FH4H4G is marked obsolete by Schneider Electric. There is no official direct-replacement order code listed; the mechanical interlock function for TeSys F contactors has been absorbed into newer platform accessories with different mounting footprints.
Integration notes
The mechanical interlock uses a sliding bar between the contactor armatures — no electrical connections, so no coil suppression or wiring to verify. Just confirm the contactor frame sizes match the stack positions listed in the compatibility table before committing the panel layout.