The Siemens SIMATIC 3RK1304-5LS40-4AA3 is a direct motor starter from the ET 200pro family, built for distributed motor control in IP65-rated enclosures. It integrates the starter, overload protection, and fieldbus connection into one package, so you skip the control cabinet and mount it directly on the machine frame or conveyor section. Rated for 12 A at 400 V AC with a Trip Class 10 thermal overload curve, it handles standard induction motors up to roughly 5.5 kW (7.5 hp) on a 400 V three-phase line. Communication runs on PROFINET and PROFIBUS DP, so it drops into Siemens S7 and third-party controllers that speak either protocol. The 2-byte input and 2-byte output process data map covers start/stop, fault reset, and status feedback without chewing up I/O on a remote rack.
IP65 protection means the housing is dust-tight and protected against water jets — rated for washdown environments on food, beverage, or packaging lines. No separate control cabinet needed; mount it via screw fixing in any orientation (vertical or horizontal) as long as the cable glands face downward. Shock resistance of 15 g for 11 ms and vibration resistance of 2 g mean it survives on vibrating conveyors, press feeders, or mobile equipment. No derating needed for normal industrial shock and vibration profiles. The 24 V DC control supply accepts 20.4 to 28.8 V, so it runs on standard 24 V industrial power supplies with tolerance for voltage drop on long cable runs. Power dissipation is 3.888 W with or without the bypass circuit engaged — negligible heat for IP65 enclosures.
Integration notes for the controls engineer
The main power infeed uses an ISO 23570 socket — a standardized 4-pin connector for distributed motor starters. The digital input signals arrive via M12 socket, the standard fieldbus connector for IP65-rated devices. No terminal block wiring inside the enclosure; it's all plug-and-play connectors. This is a direct starter only — no reversing function, no brake control. If your application needs reversing, you'll need two of these units or a different variant. The 0 digital inputs and 0 digital outputs on the module itself mean all control signals come over the fieldbus; there are no local I/O points on this unit. Dimensions are 230 mm high, 110 mm wide, 150 mm deep — compact enough to mount on a machine frame or a small sub-panel. The screw fixing pattern is standard for the ET 200pro family, so it shares mounting holes with other modules in the series.