What it is and what it does
The Siemens SIRIUS 3RK1315-6LS41-0AA5 is a direct motor starter built for harsh environments. It's rated IP65, so the enclosure and the connectors — the M12 plug for device addressing and the HAN Q4/2 connector for the main circuit — are sealed against dust and low-pressure water jets. That means it can sit right on the machine frame, not tucked away in a cabinet, and still survive washdown cycles. It's a CLASS 10 overload relay, which means it will trip within 10 seconds at 7.2× the thermal setting. For a 5.5 kW motor at 400 V, that's fast enough to protect standard squirrel-cage rotors during a stall without nuisance tripping on a normal start. The unit is a direct starter — no reversing contactor inside, and no on-site start/stop pushbuttons. Control comes from the AS-Interface network, with four digital inputs for feedback or auxiliary commands. Supply voltage is 24 V DC nominal, with a permissible range of 20.4 to 28.8 V.
Where it fits and how it mounts
The starter measures 294 mm wide, 215 mm high, and 159 mm deep. It's screw-fixed — no DIN-rail clip — so plan for four mounting holes in the panel or machine frame. Mounting position is flexible: vertical, horizontal, or flat, though horizontal is recommended for optimal heat dissipation from the CLASS 10 bimetal trip. Operating temperature range is -25 to +55 °C, with storage and transport down to -40 °C. Shock resistance is 12g for 11 ms, vibration resistance is 7 mm at 2g — solid for conveyor lines or pump skids that see mechanical chatter.
Key ratings at a glance
Rated power depends on line voltage: 5.5 kW at 400 V, 5 500 W at 500 V, 3 hp at 220/230 V, 7.5 hp at 460/480 V, and 10 hp at 575/600 V. The DC supply must stay between 20.4 and 28.8 V, with an absolute max of 31.6 V and a min of 26.5 V for reliable operation. The unit has a degree of pollution 3 rating, so it's suitable for industrial environments with conductive dust or occasional condensation. ON-delay is 85 ms, OFF-delay is 65 ms — fast enough for most sequencing but not for safety-rated instant-off applications.