The Siemens 3RK1300-1CS01-1AA0 is a reversing starter — a compact, pre-configured motor-starting unit that combines a contactor, overload relay, and reversing function in one IP65 enclosure. It's rated for 2.5 A in AC-3 duty at 400 V, which translates to a 0.9 kW three-phase motor load. The 24 V DC control supply operates across a 20.4 to 28.8 V window, so it holds through typical 24 V rail dips. Communication is via PROFIBUS DP over the backplane bus — no AS-Interface or PROFINET on this variant. The overload protection uses a bimetal relay, adjustable from 1.8 to 2.5 A, matching the motor full-load current range.
The enclosure measures 270 mm high by 140 mm wide by 134 mm deep, with an IP65 rating — meaning it's dust-tight and protected against low-pressure water jets. The main current circuit uses tab terminals; supply voltage and communication connect via the backplane bus. The load-side outgoing feeder and main energy infeed use sockets per ISO 23570, so cabling is modular — pull the connector, swap the unit.