The Siemens SIRIUS 3RV2927-7AA00 is a contactor base designed for use with 3RA2 load feeders, serving as the mounting and wiring platform for configuring direct-on-line and reversing starters. It accepts circuit breakers in sizes S00 and S0, making it a common interface part in motor control centers and distribution panels where the feeder and contactor need to be mechanically integrated on a DIN rail.
Dimensions and mounting
The base measures 63.1 mm deep, 44.8 mm wide, and 159.8 mm high. It snaps onto a 35 mm DIN rail per DIN EN 60715 and can be mounted in any orientation. The 0 mm backward clearance means the rear face sits flush against the mounting surface — no extra space needed behind the rail for wiring or airflow.
This part is a mechanical and wiring interface — it has no coil, no auxiliary contacts, and no electronic logic. Its job is to hold the circuit breaker and route the power and control wiring to the contactor that mounts on top. For a 3RA2 load feeder build, the base is the first component you snap onto the rail; the breaker and contactor then clip onto it.