SIRIUS reversing starter with AS-Interface
The Siemens SIRIUS 3RK1325-6KS41-3AA0 is a reversing motor starter rated for 0.75 kW at 400 V AC, with an IP65 enclosure that allows direct mounting on the machine frame or in a washdown zone without a separate panel. It communicates over AS-Interface for control and diagnostics, so the line integration is straightforward if you already have an AS-i master on the network. The supply voltage range is 20.4 to 28.8 V DC, with a maximum permissible of 31.6 V and a minimum of 26.5 V — stay within that window to keep the electronics happy. The 24 V DC nominal is standard for control circuits.
Trip class and motor protection
Trip class is selectable between CLASS 5, 10, 15, and 20. That means you can match the overload curve to the motor's starting profile — CLASS 5 for short acceleration times on low-inertia loads like pumps, CLASS 20 for high-inertia starts like centrifuges or large fans. The ON-delay is 85 ms and OFF-delay 65 ms, which governs how fast the starter responds to a start/stop command from the AS-i network.
Mounting position is flexible: vertical, horizontal, or flat. The recommended orientation is horizontal, but the other positions work if panel layout demands it. Fastening is by screw fixing — no DIN-rail clip, so budget for four M6 bolts and a backplate. Dimensions are 294 mm wide by 215 mm high by 159 mm deep; that's a substantial footprint, so check your gland plate clearance before committing. Shock resistance is 12g for 11 ms, vibration resistance 7 mm / 2g — tough enough for conveyor lines and machine tools.
Wiring and connectivity
The main current circuit connects via a HAN Q4/2 plug conforming to ISO 23570 — that's a standard industrial connector, so pre-wired harnesses are available. Device addressing uses an M12 plug, typical for AS-Interface nodes. There are 4 digital inputs for local sensors or pushbuttons, which can reduce the need for a separate I/O block. This is a reversing starter with reverse starting capability, but it does not support direct start. It has on-site operation via the local controls. No PROFINET or PROFIBUS DP — communication is AS-Interface only, so plan your network topology accordingly.