SIRIUS direct starter with AS-Interface and IP65 enclosure
The Siemens SIRIUS 3RK1325-6LS71-0AA0 is a fully enclosed direct starter rated for 5.5 kW at 400 V, with selectable Trip Classes 5, 10, 15, and 20. It communicates over AS-Interface (the onboard protocol), so you skip the separate fieldbus coupler if your backbone is AS-i. Supply is 24 V DC nominal, with a working range of 20.4 to 28.8 V.
The 5.5 kW at 400 V rating (7.5 hp at 460/480 V) covers most small conveyors, pumps, and fan starters in a typical 480 V plant. Trip Class selection — 5, 10, 15, or 20 — lets you match the overload curve to the motor's thermal capacity; a high-efficiency motor with a short locked-rotor time needs Class 10 or 5, while a general-purpose T-frame can take Class 20. The 25 ms ON-delay and 35 ms OFF-delay are fixed, so sequencing logic stays simple — no programmable timers inside this box. Four digital inputs are available for local pushbuttons or sensor feedback, addressed through the M12 plug. The main circuit connects via a HAN Q4/2 connector (ISO 23570), which is a standard industrial interface — panel builders will recognize the form factor. Mounting is screw-fix to a backplate; the unit can sit vertical, horizontal, or flat, though horizontal is recommended for thermal performance.
Environmental and mechanical notes
Shock resistance is 12 g for 11 ms; vibration resistance is 7 mm at 2 g. Dimensions: 294 mm wide, 215 mm high, 159 mm deep.