Reversing starter on AS-Interface — what it replaces in a panel
The Siemens 3RK4320-3HR51-1BA0 is a SIRIUS reversing motor starter — a single unit that handles forward/reverse control of a 3-phase motor up to 3.2 A at 400 V AC-3, with built-in bimetal overload protection (CLASS 10 trip class). This isn't a bare contactor stack; it's a fully integrated motor control unit (MCU) that communicates over AS-Interface, so it drops the separate I/O wiring and fieldbus gateway for a reversing station.
The short-circuit protection is designed for circuit-breaker coordination (not fuses), so the upstream breaker must be selected per Siemens coordination tables to keep the starter undamaged through a fault. Operating frequency is rated at 80 operations per hour minimum — that's about one start every 45 seconds, fine for conveyor or pump cycling but not for high-speed reversing like a positioning axis.
IP55 and mounting — where this lives in the plant
IP55 enclosure means it's dust-protected and can handle water jets from any direction — suitable for washdown areas in food processing or outdoor installation under a roof, but not for submersion or high-pressure spray. Dimensions are 182 mm wide × 220 mm high × 145 mm deep — it's a compact block that fits a standard 400 mm deep enclosure with room for the AS-Interface cable bend radius.
Lifecycle and sourcing — active, quoted to order
Substance prohibition date of 05/01/2012 indicates RoHS compliance per Siemens internal tracking — the part meets the EU RoHS directive as of that date, with no REACH SVHC declaration in this record. No minimum order quantity is stated — quoted per your line item.