What it is and where it fits
The Siemens 3RK1322-0JS02-0AA1 is an AS-Interface compact direct starter from the SIRIUS family — a fully enclosed, IP65-rated motor starting package that combines a contactor, overload relay, and AS-i bus interface in one housing. It's designed for distributed motor control right at the machine, not back in a central panel. Rated for 0.25 kW at 400 V under AC-3 duty (motor starting), with an adjustable setting range of 0.7 to 1.0 A via a bimetal overload relay. That 0.25 kW figure is the same at both minimum and maximum — the part is sized for a specific motor power class, not a wide band. The IP65 enclosure means the entire starter — contacts, overload, bus electronics — is sealed against dust and low-pressure water jets, so it can mount directly on a conveyor frame or machine base in washdown areas without a separate cabinet.
AS-Interface integration and I/O
Communication is via AS-Interface protocol (not PROFIBUS DP), which keeps wiring simple: a single two-wire flat cable carries both power and data to the starter. The unit includes two integrated inputs for local sensors (e.g., limit switches or presence detectors) and a motor brake output rated 24 V DC / 3 A — useful for holding brakes on vertical-axis motors. The 9-pole motor outgoing feeder and 9-pole power connection use tab terminals for the main circuit, so you're looking at fast-on connectors rather than screw terminals — plan your wiring harness accordingly.
Short-circuit protection and breaking capacity
The maximum short-circuit breaking capacity (Icu) at 400 V is 50,000 A — that's the fault current the integrated circuit-breaker-style short-circuit protection can safely interrupt without welding contacts or rupturing the enclosure. For a distributed starter mounted outside a panel, that rating matters because the available fault current at the machine can be substantial.
Environmental and physical fit
Operates from -25 to +55 °C ambient, which covers most factory floor conditions short of a foundry or freezer tunnel. Dimensions are 270 mm high, 120 mm wide, 190 mm deep — a compact footprint for a fully self-contained motor starter with bus communication.