SIRIUS reversing starter with AS-Interface
This is a Siemens SIRIUS 3RK4320-3CQ51-1BA2 reversing motor starter — a compact, electromechanical unit that integrates motor protection, reversing contactors, and AS-Interface bus communication into a single enclosure.
AS-Interface integration and I/O
The starter communicates via AS-Interface protocol — no PROFIBUS or PROFINET on this variant, so the bus master must be AS-i compatible. Two digital inputs are onboard for local feedback or auxiliary signals, and the unit includes a motor brake output (24 V DC brake control is not fitted, but the component is present for other brake voltages). Short-circuit protection is provided by circuit-breakers integrated into the design, and the unit is rated for up to 80 operating cycles per hour.
Mounting and environmental limits
Enclosure measures 205 mm deep, 245 mm wide, and 215 mm tall, with IP54 protection — suitable for indoor industrial environments where dust and splash are present but not washdown.
Lifecycle and compliance
Substance prohibitance date is May 1, 2012, indicating RoHS compliance per Siemens' internal substance control policy. Reference code per IEC 81346-2 is Q (switching device), and the product is designed for 1:1 assignment (one motor per starter).