AS-Interface integration — the bus-connected direct starter
The 3RK4320-3NQ54-0BA2: Designated a motor starter MCU for AS-Interface, this unit integrates bus communication directly — it speaks the AS-Interface protocol, so no separate gateway module is needed for the motor-starting function on that fieldbus. It's a direct starter design (not reversing or star-delta), meaning one contactor handles the motor run with the bimetal overload relay built into the same housing — clean single-motor control on a single node address. Two digital inputs are on board for local start/stop or interlock signals, reducing the I/O count you'd otherwise need from a remote block.
Rated load and protection — AC-3 at 10 A
At AC at 400 V the rated value is also 10 A, confirming the thermal current rating matches the motor-switching rating — no derating between continuous and motor duty at this load point. Operating voltage range is 340... 440 V, covering 400 V nominal with tolerance for weak lines or generator supply, and the control supply is 20.4... 26.4 V DC — standard 24 V control power with a solid margin.
Physical fit and mounting in the panel
Dimensions are 245 mm wide by 205 mm deep by 215 mm high — it's a substantial block, not a slim contactor; plan for the full width when laying out DIN-rail components in the enclosure. IP54 rating means it's protected against dust ingress and splashing water — suitable for control cabinets in industrial environments, not for washdown zones.
Motor brake output and short-circuit coordination
Includes a product component motor brake output — so it can directly control a holding brake on the motor shaft without an external brake rectifier or relay, saving a DIN-rail slot and wiring terminations. Short-circuit protection is designed for circuit-breakers (not fuses), and the unit has short-circuit protection built in — coordination with a Type 1 or Type 2 upstream breaker is expected per the SIRIUS manual.
Temperature range and compliance
Ambient temperature during operation spans -25... +50 °C, covering most indoor industrial conditions without derating; the bimetal overload compensates across this range. Substance prohibitance date is 05/01/2012, aligning with RoHS and REACH compliance timelines — the part meets current EU substance restrictions. Reference code per IEC 81346-2 is Q, classifying it as a switching device in the plant documentation standard.