What it is and where it fits
The Siemens 3RK1322-1JS02-0AA4 is a SIRIUS AS-interface compact starter — an electromechanical direct-on-line motor starter in an IP65 enclosure, rated 4 kW at 400 V AC-3, with a bimetal overload relay adjustable from 7 to 10 A. It integrates two inputs and a motor brake output (500 V DC / 1 A), and communicates over the AS-Interface bus. This is a self-contained unit for distributed motor control in washdown or outdoor zones; the IP65 rating means the housing and all connections tolerate hose-directed water and dust ingress, so it mounts directly on the machine frame or conveyor line without a separate control cabinet.
Key ratings and what they mean for fit
The 4 kW rating at 400 V AC-3 is the motor-switching capacity under IEC 60947-4-1 — that's the standard for contactors and starters controlling squirrel-cage motors. AC-3 covers starting and disconnecting motors under load, so this rating governs the largest standard three-phase induction motor this starter can handle. The 50 kA short-circuit breaking capacity (Icu) at 400 V means the integrated short-circuit protection (circuit-breakers, per) can safely interrupt a fault current up to 50,000 A without the upstream device needing to clear it — critical for high-fault-capacity installations. The 7-10 A setting range is the bimetal overload relay's adjustment window; set it to match the motor nameplate FLA.
Integration and wiring
Dimensions are 270 mm high, 120 mm wide, 190 mm deep. The main current circuit uses tab terminals — expect blade-type quick-connects, not screw terminals. The AS-Interface protocol handles both power and communication over a two-wire flat cable; no PROFIBUS DP here. The brake output is rated 500 V DC / 1 A, sized for a small holding brake on the motor shaft. Ambient operating range is -25 to +55 °C. The equipment marking per IEC 81346-2 is 'Q', the standard identifier for switching devices in a plant schematic.