What this part is and what it does
The Siemens 3RK1322-0KS02-1AA1 is an AS-Interface compact reversing starter in the SIRIUS 3RK1 family, designed as a fully integrated motor starting and protection unit for distributed automation. It combines a reversing contactor, bimetal overload protection, short-circuit protection via circuit-breakers, and bus communication into a single IP65 enclosure — meaning it mounts directly on the machine frame or conveyor section, not inside a central control panel. Rated for 0.37 kW at 400 V AC-3 duty, the starter's adjustable overload range covers 0.9 to 1.25 A, making it a fit for small reversing motor loads such as shuttle gates, diverters, or indexing tables. The electromechanical switching contact handles the reversing logic internally, so the AS-i network only sends direction and start/stop commands. A built-in motor brake output (24 V DC / 3 A) is included for holding-brake applications, and the unit provides two integrated inputs for local sensors or pushbuttons — typical for a stand-alone reversing station where you want local control plus network visibility.
Key ratings and what they mean for fit
The 0.37 kW AC-3 rating at 400 V is the motor switching capacity under the most common induction-motor starting condition (AC-3: starting and switching off running motors). This is not a resistive-heating rating — it governs the inrush and breaking of motor current. The 50 kA short-circuit breaking capacity (Icu at 400 V) means the integrated circuit-breaker can safely interrupt a fault of that magnitude without upstream devices needing to clear it. IP65 protection means the housing is dust-tight and protected against low-pressure water jets from any direction — suitable for washdown areas, outdoor conveyor sections, or food-processing zones where a central panel would be impractical. The AS-Interface protocol connection (yes, not PROFIBUS DP) is the communication backbone here. The starter acts as an AS-i slave, receiving direction and start/stop telegrams and reporting back status and overload trips. Two integrated inputs allow connection of limit switches or emergency-stop buttons directly to the unit, reducing field wiring. Ambient temperature range of -25 to +55 °C covers most industrial environments, including unheated warehouses or outdoor installations under cover.
Panel and machine integration
The 190 mm depth, 120 mm width, and 270 mm height define the envelope for machine-mounted installation. Tab terminals on the main current circuit accept push-on connectors for the motor and power cables; the 9-pole motor and power connectors are pre-wired to the unit's internal bus. No DIN rail is needed — the IP65 housing is designed for direct machine or bracket mounting, with the AS-i cable daisy-chained through the integrated bus connection.