The Siemens 3RA2923-2MB2 is a reversing starter kit purpose-built for the SIRIUS 3RC7 intelligent link module (ILM) family. It provides the mechanical and electrical reversing interlock for two contactors in a single assembly, sized for mounting on a 60 mm busbar system or a 3RV29 infeed system.
What the 3RA2923-2MB2 does on the line
This kit handles the reversing logic for a motor starter built around 3RC7 ILMs. Instead of wiring separate mechanical interlocks and busbars, the 3RA2923-2MB2 snaps onto the busbar and accepts two 3RC7 modules, providing the reversing interlock and power distribution in one package. It is the standard way to build a reversing starter in the SIRIUS compact form factor. Mounting options are the 60 mm busbar system common in IEC panels, or the 3RV29 infeed system for feeder integration. The kit's packaging dimensions of 105.5 x 45.5 x 49.5 mm give a sense of the panel space it occupies — roughly the width of a single 3RC7 module plus the interlock mechanism.
RoHS compliance is confirmed effective October 1, 2023, so the kit meets the substance restrictions for European markets.