The LA9FL4K4G is a mechanical interlock from the TeSys F range, designed to prevent simultaneous closure of two contactors in a reversing or changeover configuration. It mounts in a 3-vertical stack, mechanically coupling the moving contacts so only one device can be in the ON position at any time. This interlock is compatible with bottom-position LC1F185 through LC1F225 3P or 4P contactors and CR1F185 3P or 4P reversing contactors, middle-position LC1F500 2P/3P/4P and CR1F500 3P/4P, and top-position LC1F630 3P/4P, LC1F800 3P, and CR1F630 3P/4P units. It is the mechanical safety backbone for any TeSys F reversing starter or transfer switch assembly.
Because it is a mechanical accessory with no electronics, there is no firmware revision or compliance documentation beyond the standard RoHS/REACH declarations that cover the TeSys range.
Installation note
Mounting position is 3 vertical — meaning the three contactors stack vertically on the DIN rail or panel plate. The interlock clips between them; no additional wiring is required. Verify the stack order matches the compatibility table: bottom for the 185–225 frame, middle for the 500 frame, top for the 630/800 frame.