The Schneider LAD9V14 is an electrical interlocking accessory from the TeSys Deca range, designed for star-delta motor-starting assemblies that use three contactors in the LC1D09 through LC1D38 frame size. It provides electrical interlocking between the three contactors — line, star, and delta — so that the star and delta contactors cannot close simultaneously, which would short the motor windings. The accessory is rated for 3-pole contactors and mounts directly onto the contactor assembly without additional wiring for the interlock logic.
This interlock is specific to the TeSys Deca contactor family — it clips onto the front of the contactor assembly and uses the same DIN-rail mounting footprint, so no extra panel space is consumed. It is wired in series with the coil control circuits of the star and delta contactors; a normally-closed auxiliary contact on each contactor breaks the other's coil path, enforcing the interlock.