The Siemens 3RT2017-2BW42 is a SIRIUS power contactor in the size S00 frame — the smallest footprint in the SIRIUS contactor family, at 45 mm wide on the DIN rail. It switches loads via a 48 VDC coil and terminates through spring-type terminals on both the coil and main contacts. The 48 VDC coil is a common control voltage in industrial panels with DC power supplies. The spring-cage terminals accept solid or stranded wire from 0.5 to 4 mm², which wires up clean without needing a screwdriver torque check — just strip to 8–10 mm and push in.
The mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward, so it fits tight enclosures or angled subpanels. Clearance needs: 10 mm upward, 10 mm forward, 10 mm downward, and 6 mm at the sides — keep those gaps for airflow and arc flash. Rated for operation from -25 to +60 °C and storage from -55 to +80 °C.
No cross-reference or alternate MPN is required — this is the current-production part.