Siemens 3RT2025-1KB40 SIRIUS 3RT contactors, 3-pole, up to 250 kW. Siemens 3RT2025-1KB40 is the exact printed commercial reference for a contactor / contactor accessory in the SIRIUS 3RT Contactors range. Siemens' official product description is: power contactor, AC-3e/AC-3, 17 A, 7.5 kW / 400 V, 3-pole, 24 V DC, 0.7-1.25* Uc, with plugged-in varistor, auxiliary contacts: 1 NO + 1 NC, screw terminal, frame size: S0, suitable for PLC outputs, no auxiliary switch can be added.