The Siemens 3RT1627-1AB01 is a SIRIUS capacitor contactor, size S0, rated for AC-6 switching of capacitor banks at 25 kVAr / 400 V. The coil is 24 V AC, 50 Hz only. It has three main NO contacts and one auxiliary NO contact, all screw-type terminals. The AC-1 resistive rating is 35 A at 400 V, but the part is specifically designed for AC-6 capacitor switching — that's the rating that governs selection. The 25 kVAr figure at 400 V matches common power-factor correction banks in industrial distribution panels.
Side-by-side mounting is permitted with no spacing required. Dimensions are 45 mm wide, 100 mm high, 135 mm deep — the depth is the main space consideration in a shallow enclosure. Operating ambient is -25 to +60 °C.