The Siemens 3RT1922-2D is a SIRIUS-branded mechanical connector designed to interlock two S0-frame contactors. It physically prevents both contactors from closing simultaneously, which is the standard approach for mechanical interlocking in reversing or dual-feed motor starter applications where a common-mode short must be avoided. The part snaps onto the contactor face and links the armatures — no wiring required.
The official lifecycle stage for 3RT1922-2D is current, but the manufacturer's own description flags it as a phased-out product with the successor being the SIRIUS 3RT2 series. For a BOM line that was originally specified with this order code, the immediate procurement question is whether the panel builder has already transitioned to the 3RT2 mechanical interlock, or whether a last-time buy of the 3RT1922-2D is needed to maintain a running install base.
Integration note
This connector is specific to the S0 contactor frame size (3RT1.2 series). It mounts on the front of the contactor and links the mechanical flags that follow the armature position. No electrical connections are involved — it is purely a mechanical barrier. The interlock works by physically blocking the opposing contactor's armature from closing when the first one is engaged. Panel builders should verify that the 3RT1.2 contactor pair is still in the cabinet; if the contactors have been upgraded to the 3RT2 series, this interlock will not fit.