Siemens 3RT2025-1BB40 Three-Phase Power Contactor

The Siemens Sirius 3RT2025-1BB40 is a three-pole S0-size power contactor designed for AC-3 duty, capable of switching three-phase motors up to 7.5 kW (about 10 HP) at 400 V with a 24 V DC coil. Its main contacts are rated for 17 A at 400 V, and it includes one auxiliary contact (1 normally open and 1 normally closed) for control or interlock signaling. Wiring uses screw terminals, and the device is positioned in the S0 family for vertical mounting, with IP20 protection on the front/terminal area. This model is part of Siemens’ SIRIUS 3RT2 power contactor lineup, offering reliable motor-start capabilities in compact, DIN-rail-friendly control panels.