What this AS-i compact reversing starter does on the line
The Siemens 3RK1322-1FS02-1AA0 is an AS-interface compact reversing starter rated for 1.9 kW at 400 V AC-3 duty — that's the motor-switching current for a standard 3-phase induction motor, not the resistive-heater curve. The setting range of 3.5 A to 5 A (full-scale value 5 A) means you dial in the motor full-load current via the bimetal overload relay built into the housing; there is no separate thermal block to order. The 50 kA short-circuit breaking capacity at 400 V (Icu) gives you the fault-clearing headroom to mount this downstream of a 50 kA-rated feeder without adding a current-limiting fuse upstream — useful when the panel SCCR requirement is tight. This is an electromechanical reversing starter with a bimetal motor-protection element. It communicates over AS-interface (AS-i), not PROFIBUS DP, so it belongs on an AS-i network segment — typically a daisy-chain of sensors and actuators running a single two-wire cable that carries both power and data. The 9-pole motor outgoing feeder and 9-pole power connection with two integrated inputs simplify wiring: one cable carries the motor leads, feedback, and AS-i bus connection.
The housing measures 270 mm high, 120 mm wide, and 190 mm deep. That depth (190 mm) is the dimension from the mounting surface to the furthest protrusion — important when the enclosure depth is marginal. The width (120 mm) determines the DIN-rail or mounting-plate pitch; leave clearance for the AS-i cable bend radius and the 9-pole connector plug.