Reversing starter with integrated PROFIBUS DP for distributed motor control
The Siemens 3RK1303-6DS74-3AA0 is a SIRIUS 3RK1 reversing starter with solid-state switching contacts, designed for distributed motor control in industrial automation. It integrates a PROFIBUS DP communication interface, four parameterizable digital inputs, and full motor protection into a single IP65-rated enclosure. Rated at 12 A for AC-3 duty at 400 V, this starter handles reversing motor loads up to that current — suitable for conveyors, pumps, and small drives requiring forward/reverse operation. The 100 kA rated short-circuit current (SCCR) at 400 V means it safely interrupts faults up to that level without cascading upstream, simplifying panel coordination. The IP65 protection class allows deployment in washdown or dusty environments without a separate enclosure — the housing and connectors withstand hose-directed water and airborne particulates typical of food-and-bev or material-handling lines.
Dimensions, connectivity, and mounting
The unit measures 250 mm high, 130 mm wide, and 125 mm deep. It connects via hybrid plugs and sockets per ISO 23570 for the main energy infeed and load-side outgoing feeder, plus a hybrid socket for communication transmission. The supply voltage line-side uses a hybrid plug; digital input signals terminate at two M12 sockets. Operating voltage is rated 400 to 500 V AC, with a DC supply voltage of 24 V (permissible range 20.4 to 28.8 V). The minimum operating frequency is 1 cycle per hour, reflecting its design for intermittent reversing duty rather than continuous jogging.
Lifecycle and compliance
Substance prohibited substance date is 05/01/2012, confirming RoHS compliance from that date forward. The part uses fuse-based short-circuit protection and provides full motor protection.