The Siemens 3RK1300-1JS01-1AA0 is an EM 300 RS electromechanical reversing starter designed for the ET 200X distributed I/O system. It integrates a reversing contactor pair, bimetal overload relay, and PROFIBUS DP communication into a single IP65-rated enclosure. Rated for AC-3 duty at 4.0 kW on a 400 V supply, with a setting range of 7.0 to 10 A. The bimetal overload protection tracks motor heating directly — no electronic curve to configure, just a thermal replica of the winding. For a 4 kW motor at 400 V, that setting range covers the full-load current typical of a 7.5 to 10 A motor nameplate.
This is a direct-on-line reversing starter for a three-phase motor — forward, reverse, and overload protection in one package. It mounts on the ET 200X backplane or directly in the field via its IP65 housing. PROFIBUS DP is the onboard fieldbus. No AS-interface on this variant. The bus connection carries start/stop, direction, and feedback signals — the reversing logic is handled inside the starter, not in the PLC, so a single PROFIBUS node controls the entire motor direction. Operating voltage is 400 to 500 V AC, three-phase. Ambient temperature range of 0 to 55 °C covers most industrial enclosures and field-mounted installations.