The LA9FG4G4G is a mechanical interlock from the TeSys F range, designed to prevent simultaneous closure of two or three contactors in a reversing or star-delta configuration. It physically blocks the armatures of vertically stacked contactors when one is engaged. This accessory interlocks top, middle, and bottom positions for LC1F185 through LC1F225 contactors, both 3-pole and 4-pole variants, as well as CR1F185 through CR1F225 control relays. The mounting position is specified as three vertical units.
What to expect in the panel
This interlock mounts directly onto the contactor faces, occupying no additional DIN-rail space. The mechanical linkage is a positive-break type — if one contactor welds shut, the interlock prevents the other from closing, which is the failure mode that matters for motor reversing circuits. No wiring or auxiliary contacts are involved.