The Siemens 3RK1315-6KS71-0AA5 is a SIRIUS direct motor starter — a fully enclosed, IP65-rated unit that combines a contactor and overload relay in one housing, designed for direct-on-line starting of three-phase motors up to 0.75 kW at 400 V (0.7 hp at 460/480 V). It is a CLASS 10 trip device, so it will disconnect the motor within 10 seconds of a locked-rotor condition at the set current — standard for most pump, fan, and conveyor applications where the motor accelerates quickly. The unit communicates over AS-Interface (the only fieldbus protocol listed), with device addressing via the M12 plug. Four digital inputs and one digital output are available for local sensors or status feedback.
Power supply and control voltage
Control supply 24 V DC nominal, rated range 20.4 to 28.8 V DC, maximum permissible 31.6 V DC. Minimum permissible voltage is 26.5 V DC. ON-delay is 25 ms, OFF-delay is 35 ms — fast enough for most sequencing but not safety-rated for a stop category; this is a standard motor starter, not a safety contactor.
Mounting is by screw fixing (not DIN rail), and the unit can be installed vertically, horizontally, or flat. The recommended orientation is horizontal for best thermal performance. Dimensions are 294 mm wide, 215 mm high, and 159 mm deep — plan for a backplate or enclosure that accommodates this footprint. It is rated for shock resistance of 12g / 11 ms and vibration resistance of 7 mm / 2g — robust enough for most industrial machinery, including compressors and conveyors.