SIRIUS MCU motor starter for AS-Interface — 1.25 A solid-state direct starter
The Siemens 3RK4320-5DQ64-0BA3 is a SIRIUS MCU motor starter designed as a direct starter with solid-state switching contacts and solid-state motor protection (CLASS 10 trip class). This unit communicates over AS-Interface (the protocol is supported per the spec), making it a drop-in component for AS-i bus architectures common in material handling and assembly lines. It does not support PROFIBUS DP or PROFINET natively. Control supply is 20.4 to 26.4 V DC, so it integrates into standard 24 V DC control panels.
Enclosure, mounting, and environment
Rated IP54, the enclosure is suited for control cabinets in industrial environments where dust and splash protection is needed — not for washdown zones. Dimensions are 290 mm wide, 215 mm high, and 205 mm deep. Ambient temperature range during operation is -25 to +50 °C.
Inputs, brake control, and short-circuit protection
Two digital inputs are onboard. The unit includes a motor brake output (component present) supporting 400 V AC brake control; it does not support 24 V DC, 180 V DC, or 500 V DC brake control. Short-circuit protection is provided via circuit-breakers. The design of short-circuit protection is circuit-breakers, and the unit itself has short-circuit protection built in.