The Siemens 3RK1322-0BS12-0AA4 is an AS-interface compact starter — a direct-on-line (DOL) motor starter with solid-state motor protection and solid-state switching contacts, all in an IP65-rated enclosure. It's designed for distributed motor control in automated lines where the starter lives out on the machine frame, not back in a central panel. The IP65 rating means the enclosure and the bus connection withstand washdown and dust ingress, so it's suited for food-and-bev, packaging, or material-handling zones where hosing down the line is routine. The unit communicates over AS-interface (AS-i) protocol — no PROFIBUS DP onboard — and includes two integrated inputs for local sensors or pushbuttons. The motor brake output (rated 500 V DC / 1 A) handles internally supplied brakes, so a separate brake contactor is not needed. Power connections are tab terminals, sized for the main circuit.
The setting range is 2 A to 5.95 A full-scale, covering motor FLCs from about 0.75 kW up to 2.2 kW at 400 V AC-3 duty. AC-3 is the standard motor-starting category (squirrel-cage induction motors: starting, switching off during running). The 2.2 kW rating at 400 V is the headline — it handles a 3 HP motor on a 400 V three-phase line. The minimum 0.75 kW means it can also be set down for smaller motors without losing protection resolution. The short-circuit protection design uses fuses, so the installer provides the fuse rating per the manufacturer's coordination table. That covers cold warehouses and warm machine cabinets without derating, but note the upper end — if the starter is mounted near a hot motor or in direct sun, verify the local ambient stays under 55 °C.
Dimensions are 270 mm high, 120 mm wide, 190 mm deep. The IP65 enclosure is designed for machine-mounting — bolt it to a subframe or bracket near the motor, not inside a panel. The AS-i bus cable connects via the integrated bus communication function (product function Bus communication: Yes), and the two integrated inputs can be wired to limit switches or emergency-stop contacts local to the motor. The equipment marking per DIN EN 61346-2 is Q, which designates it as a motor starter in the schematic. The 9-pole power connection carries the motor leads, brake wiring, and AS-i bus — a single multi-conductor cable from the starter to the machine, simplifying the wiring harness compared to running individual motor and brake cables back to a panel.