What this SIRIUS reversing starter is
The Siemens 3RK1395-6KS41-1AD0 is a SIRIUS reversing motor starter in an IP65-rated enclosure — built for direct-on-line reversing of three-phase motors up to 0.75 kW at 400 V or 1 hp at 575/600 V. It's a self-contained unit with the contactors, overload relay, and control logic integrated, so you don't need to piece together a reversing contactor pair and a separate overload block. Supply voltage is 24 VDC (20.4 to 28.8 V range), and the overload trip class is selectable between 5, 10, 15, and 20 — meaning you can match the thermal protection to the motor's starting profile, from quick-starting fans to high-inertia loads.
Mounts via screw fixing (not DIN rail), so plan for four mounting holes in the backplate. The enclosure measures 294 mm wide by 215 mm high by 148 mm deep — that's a substantial footprint, so check your panel layout before committing. It can be installed vertical, horizontal, or flat, which gives flexibility in tight cabinets. The main circuit connects via a HAN Q4/2 plug connector per ISO 23570 — a standard industrial connector, not hardwired terminals. That means you can pre-wire the panel harness and plug the starter in during commissioning, saving labor on changeouts.
I/O and control logic
Four digital inputs and two digital outputs are onboard, so you can wire start/stop and direction commands directly without an extra I/O block. The starter has a built-in ON-delay of 85 ms and OFF-delay of 65 ms — these are fixed, not adjustable, so factor them into your sequence timing if you're coordinating with other devices. It supports reverse starting (obviously, being a reversing starter) but does not support direct start or on-site operation — meaning it's intended for remote control via the digital inputs, not a local pushbutton station on the enclosure.
Rated IP65, so it's suitable for washdown environments or outdoor cabinets — dust-tight and protected against water jets. Shock resistance is 12g for 11 ms, and vibration resistance is 7 mm at 2g — solid enough for most industrial machinery, including conveyors and pumps mounted near the motor.