Siemens 3RT1025-1B Contactor

Siemens Sirius 3RT1025-1B Contactor is a three‑pole motor starter with a 24 V DC coil, designed for reliable DC‑control of 3‑phase loads in industrial panels. It delivers AC‑3 switching up to 17 A (about 7.5 kW at 400 V) and AC‑1 up to 40 A, making it suitable for starting and running modest industrial motors, conveyors, pumps, and fans. The unit is a Size S0 device with screw terminals and is mountable on a 35 mm DIN rail (DIN EN 50022), allowing side‑by‑side installation in compact control cabinets. This model is listed as part of Siemens’ Sirius 3RT1025 family, with a documented successor in many catalog pages as 3RT2025-1BB40, and the 3RT1025‑1B variant specifically uses a 24 V DC coil. With its robust three‑pole configuration, it provides clear, industrial‑strength switching for panel builders and maintenance techs seeking a compact DC‑coil contactor for mid‑range motor control applications.