What this SIRIUS starter delivers
The Siemens 3RA2125-1JA24-0AP6 is a SIRIUS non-fused motor starter, size S0, built as a direct starter — it combines a contactor and a thermal bimetallic overload relay in one package, saving panel space and wiring time. The supplied contactor is a 3RT2024-1AP60, and the link module is 3RA2921-1AA00 — the whole assembly arrives as a single orderable unit, no separate picking of contactor and overload.
Mounting and panel fit
Mounting position is vertical only, with 30 mm clearance above and 10 mm forward for airflow and wiring access — the 97.1 mm depth leaves room for the main power cables in a shallow enclosure. Stranded main contacts accept 1 to 10 mm², or two conductors of 2.5 to 6 mm² each — useful for daisy-chaining through the feeder without a separate terminal block.