Siemens 3RT2028-2NB30 SIRIUS Power Contactor
The Siemens 3RT2028-2NB30 is a SIRIUS power contactor in the S0 frame size, designed for switching motor loads and resistive circuits in control panels. It carries a 24 VDC coil rated at 10 A and uses spring-cage terminals for quick wiring — solid or stranded from 1 to 10 mm².
Mounting and Panel Fit
Mounts on 35 mm DIN rail per DIN EN 60715 with a screw-and-snap-on method. The S0 footprint is 45 mm wide, 102 mm tall, 107 mm deep. Clearance: 10 mm upwards, forwards, and downwards; 6 mm at the side. Mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward. This fits standard panel layouts without rework.
Coil and Switching Performance
Coil rated 21–28 VDC, inrush peak 3 A. Operate and release times are 30–50 ms for both AC and DC. Arcing time is 10 ms. Mechanical life typical 10 million operations. Switching frequency varies by duty: up to 1,000 cycles/h at AC-1, 750/h at AC-2, AC-3, AC-3e, and 250/h at AC-4. The AC-1 rating (resistive load) is the highest cycle rate; AC-4 (plugging/inching) is the most demanding and halves that rate.