The Siemens 3RK1325-6KS41-3AA5 is a SIRIUS reversing motor starter that controls forward/reverse of a three-phase motor up to 0.75 kW at 400 V, with an IP65 enclosure for machine-mount or washdown zones. It communicates over AS-Interface (no PROFIBUS or PROFINET onboard), draws 24 VDC from the AS-i bus (20.4–28.8 V range, max 31.6 V), and includes four digital inputs for local sensors or pushbuttons.
The 0.75 kW at 400 V rating (AC-3 duty implied by the motor-starter class) tells you the maximum induction motor it can switch under load — sized for a small conveyor, pump, or fan. The trip-class selector (CLASS 5, 10, 15, 20) lets you match the overload curve to the motor's starting profile: Class 10 for standard starts, Class 20 for high-inertia loads like centrifuges. The 24 VDC supply comes from the AS-Interface bus, so no separate control transformer is needed — but the bus must be able to deliver the starter's inrush. The ON-delay of 85 ms and OFF-delay of 65 ms are fixed; if your sequence needs faster response, this part won't deliver it.
Screw fixing to a backplate or machine frame; mounting position can be vertical, horizontal, or flat — the only restriction is a horizontal recommendation for the AS-i connection orientation. Dimensions are 294 mm wide × 215 mm high × 159 mm deep — allow clearance for the M12 addressing plug and the HAN Q4/2 main-circuit connector. The main power circuit uses a HAN Q4/2 plug (ISO 23570), and device addressing is via an M12 plug — both are field-wirable but require the mating connectors (not included). The four digital inputs are also M12-terminated.