What this SIRIUS direct starter is and what it does
The Siemens 3RK1395-6LS41-0AD5 is a SIRIUS direct motor starter in a self-contained IP65 enclosure, rated for 12 A at 400 V AC and 5.5 kW motor output. It integrates the contactor, overload relay, and control electronics into one package, so you skip the separate panel wiring for each component. The 24 VDC control supply (20.4... 28.8 V) powers the onboard logic and the four digital inputs and two digital outputs, making it a drop-in node for a distributed I/O architecture rather than a traditional central-panel starter.
Key ratings and what they mean for fit
The 12 A at 400 V AC rating (AC-3 duty, motor switching) is the headline number that governs motor sizing — it matches a 5.5 kW four-pole induction motor on a 400 V line. The trip class is selectable among CLASS 5, 10, 15, and 20, which means you set the overload curve to match the motor's startup profile: class 10 for standard squirrel-cage motors, class 20 for high-inertia loads like fans or crushers. The IP65 rating means the enclosure is dust-tight and protected against low-pressure water jets, so it can be mounted directly on the machine frame or in a washdown zone without a separate cabinet.
Mounting and integration
Mounting is via screw fixing, and the unit can be installed vertically, horizontally, or flat — the horizontal orientation is recommended for optimal heat dissipation. Dimensions are 148 mm deep, 294 mm wide, and 215 mm high, so it occupies a footprint roughly the size of two contactors side by side. The main power connection uses a HAN Q4/2 plug per ISO 23570, which is a standard industrial connector for motor circuits; the control wiring lands on the onboard digital I/O terminals. Ambient operating range is -25 to +55 °C, with storage and transport tolerance from -40 to +70 °C.