The Siemens 3RA2712-1CA00 is a Sirius function module that snaps onto the front of a communication-capable contactor (3RT20…-…..-0CC0) to add AS-i bus communication and star-delta (wye-delta) starting logic. It takes its 24 V DC control supply from the AS-i network, so no separate control wiring is needed for the coil — the module handles the switching sequence internally. The screw terminals accept 0.5 to 4 mm² solid or 2x 0.5 to 2.5 mm² stranded, with core-end processing up to 2.5 mm² per clamp.
The module comes as a single unit with screw-type terminals for auxiliary and control circuits. The terminals are removable, which means you can pre-wire the harness on the bench and snap the terminal block onto the module after it's mounted on the contactor. No separate mounting bracket or accessory kit is required — it plugs directly onto the contactor front. The kit is complete: module, terminals, and the varistor surge suppressor are integrated.
This module is sized for the S00, S0, S2, and S3 contactor frames. It adds 45 mm width and 37 mm height to the contactor stack, with a depth of 75 mm. The front is IP20 finger-safe per IEC 60529, and touch protection is verified for vertical contact from the front.