What it is and where it goes
The Siemens 3RK1322-0DS02-0AA3 is an AS-i compact direct starter — a self-contained DOL motor starter in an IP65 enclosure rated for washdown environments. It's designed for decentralized motor control on an AS-interface network, meaning you run the motor control out to the machine rather than back to a central panel. The electromechanical switching contact handles the motor start/stop, and the bimetal overload protection is set for a 0.22…0.32 A range (cites:,). At 400 V AC-3 duty it's rated for 0.09 kW motor loads, and the short-circuit breaking capacity sits at 50 kA at 400 V — meaning it can safely interrupt a fault up to that level without upstream devices needing to clear it (cites:,). The motor brake output is integrated, so you don't need a separate brake contactor for motors with holding brakes (cites:).
Integration and wiring reality
This unit is panel-mount, not DIN-rail — the 190 mm depth, 120 mm width, and 270 mm height mean you're bolting it to a backplate or machine frame, not snapping it onto a rail (cites:,). Main current circuit connects via tab terminals, so expect fast-on connectors rather than screw clamps (cites:). The 9-pole motor outgoing feeder and 9-pole power connection are fixed; you're wiring the motor cable and the AS-i bus cable directly to the unit. Ambient temperature range is -25 to +55 °C during operation, which covers most factory-floor conditions but derate if it's sitting next to a hot process (cites:). The IP65 rating means the housing is dust-tight and protected against water jets — fine for washdown zones, food processing, or anywhere you hose down the machine (cites:).
What the ratings mean for fit
The 0.22…0.32 A setting range is narrow — it's matched to a specific small motor (0.09 kW at 400 V). If your motor draws more than 0.32 A full-load, this starter won't cover it. The AC-3 rating of 0.09 kW at 400 V confirms it's for squirrel-cage induction motors starting under load. The 50 kA SCCR at 400 V is high for a starter this size — it means the unit can handle a substantial fault without needing an upstream current-limiting fuse or breaker to coordinate. AS-interface protocol is built in, so it communicates directly on the AS-i bus without an extra gateway module. The two integrated inputs let you connect limit switches or pushbuttons locally, reducing wiring back to the controller (cites:).