The Siemens 3RK1323-6ES81-3AA3 is an ECOFAST reversing starter with solid-state switching and full motor protection, designed for controlling and reversing three-phase motors up to 1.5 kW at AC-3 duty on 400 V supplies. It's built as a self-contained unit for washdown environments — the IP65 enclosure means the housing and connections tolerate hose-down cleaning, so it suits food-and-bev lines, car washes, or outdoor conveyor sections where dust and moisture are constant. The part integrates via AS-Interface (AS-i) for bus communication, with a built-in motor brake output and two parameterizable speeds. That makes it a drop-in smart motor starter for distributed I/O architectures — you don't need a separate contactor, overload relay, or reversing contactor pair in the panel. The main current circuit connects through tab terminals, so wiring is a push-on affair rather than screw-clamp terminations.
The headline motor rating is 1.5 kW at AC-3 switching category on 400 V. AC-3 is the standard duty for squirrel-cage motors — starting, running, and plugging/reversing during operation. So this starter handles a 1.5 kW motor running at 400 V three-phase under normal starting conditions. The solid-state switching means no contact wear from arcing during reversals, which matters for frequent reversing applications like shuttle conveyors or indexing tables. That's the maximum fault current the unit can safely interrupt when protected by the specified upstream fuse — it won't explode or weld contacts under a high-energy fault.
Integration notes
The IP65 enclosure allows direct machine-mounting without a separate control cabinet, which saves panel space and wiring. Tab terminals on the main circuit mean you'll need mating female quick-connects rated for the motor current (4 A full-scale, 0.6 A initial). The AS-Interface connection handles both power and communication on a two-wire flat cable, so you don't run separate control wires for start/stop and direction commands. That simplifies field wiring significantly — one cable carries 24 V DC power and the AS-i signal to the unit. The brake output is built in, so you don't need an external brake rectifier or contactor for motors with holding brakes.