What this connector does in a reversing contactor assembly
The 3RA1942-2G is a mechanical interlock connector for SIRIUS S3 contactors, designed specifically for 4-pole reversing assemblies where two contactors share a common load and must never close simultaneously. The connector enforces a 10 mm clearance between the contactor faces — that gap is the physical barrier that prevents both contactors from pulling in at the same time, which would short the phases through the reversing bridge. It ships as a kit of two mechanical connectors per combination, so one order covers one reversing pair. The part is branded SIRIUS, Siemens' modular contactor and motor starter platform for panel builds up to 400 V / 690 V class.
Lifecycle reality — active but with a successor
For a procurement decision: if the BOM already carries the 3RA1942-2G and the line is running, the current lifecycle status means you can still source it. For a new panel build or a BOM revision, the successor 3RA2942-2G is the cleaner path — same S3 reversing function, same clearance, same mechanical interface.
Compliance and documentation
This indicates the 3RA1942-2G was designed to meet RoHS restrictions on lead, mercury, cadmium, and other substances from that date forward.