What this mechanical interlock does in a reversing starter
The 3RA1924-2B is a SIRIUS mechanical locking device that prevents simultaneous closure of two contactors in a reversing starter — the classic interlock that keeps forward and reverse contactors from pulling in together and shorting the phases. It mounts laterally on reversing starters in frame sizes S0, S2, and S3, and each contactor carries one NC auxiliary contact as part of the interlock circuit.
Lifecycle reality — phased out, successor named
Siemens lists this as a phased-out product. For BOM lines that still specify 3RA1924-2B, availability runs through independent distribution channels. Quantities are confirmed at RFQ; no stock-holding claim is made here.
RoHS compliance date on record
The substance prohibitance date is 07/01/2006, which aligns with the original EU RoHS directive effective date — the part meets the 2006 RoHS threshold for the six restricted substances.