Star-delta coupling module for 3RT2 contactors
The Siemens 3RA2911-0 is a SIRIUS coupling module with a pre-wired connecting cable that implements the star-delta (wye-delta) transition between two 3RT2 contactors — it handles the interlocking and timing logic that holds the unit on the grid during the changeover, provided the control circuit is wired to the correct terminal sequence. The module is designed for mounting panel integration, meaning it bolts into the control panel backplate rather than snapping onto a DIN rail — the physical footprint matches the 3RT2 contactor pair it couples, so the panel layout stays compact.
Lifecycle and sourcing — current production, quoted to order
Stock is held in ready inventory with full manufacturer traceability; production quantities are quoted against the BOM from authorized distribution, and lead time plus volume pricing are confirmed at RFQ.
Panel integration and contactor pairing
This coupling module is specific to the Siemens 3RT2 contactor series — the connecting cable length and terminal assignments are factory-matched to the 3RT2 coil and auxiliary contact positions, so the star-delta transition sequence is deterministic without field wiring errors. Mounting the module on the panel backplate means the installer positions it adjacent to the two 3RT2 contactors, routes the pre-terminated cable between them, and connects the control voltage to the module's input terminals — the module itself contains no power contacts, only the interlocking logic.