What it is and where it fits
The Siemens 3RK1322-0FS02-1AA0 is an AS-Interface compact reversing starter in an IP65-rated enclosure. It's an electromechanical reversing starter with bimetal motor protection and circuit-breaker-based short-circuit protection, designed for distributed motor control on a machine frame or conveyor line where you need forward/reverse without a separate panel. The IP65 rating means the housing and the tab terminals tolerate washdown environments — food processing, packaging, or any line where hoses are part of the cleaning cycle. The unit communicates over AS-Interface (AS-i), so it drops onto a two-wire bus cable for both power and data. No PROFIBUS DP on this variant — the onboard bus communication is strictly AS-i. That simplifies wiring: one flat cable carries the 24 VDC supply and the control signals to the starter, and the reversing contactor set handles the motor switching locally.
Key ratings and what they mean for fit
The motor rating is 0.12 kW at AC-3 duty on a 400 V supply. AC-3 is the standard category for squirrel-cage induction motors — starting, stopping, and reversing under load. That 0.12 kW figure governs the real-world motor size you can switch; it's not the contactor's thermal current but the motor power the bimetal overload can protect. The setting range of 0.35 A to 0.5 A matches small motors in that power band — think a fractional-horsepower conveyor drive or a small agitator. The short-circuit breaking capacity is 50,000 A at 400 V. That's a high interrupting rating for a compact starter — it means the unit can clear a fault on a high-capacity supply transformer without upstream fuses needing to coordinate. The circuit-breaker-style short-circuit protection is integrated, so you don't need a separate motor circuit protector ahead of it. Ambient temperature range is -25 °C to +55 °C during operation. That covers most indoor industrial environments and cold storage areas. The IP65 seal keeps moisture and dust out across that range.
Physical integration and wiring
Dimensions are 190 mm deep, 120 mm wide, 270 mm tall. The width is the key panel-space number — at 120 mm, it's wider than a typical contactor but the enclosure integrates the overload relay, reversing contactors, AS-i interface, and the circuit-breaker short-circuit protection into one package. Main circuit connections are tab terminals, which are common for quick-connect wiring in distributed installations. The unit includes a 9-pole motor outgoing feeder and a 9-pole power connection, plus two integrated inputs for local sensors or pushbuttons.