The Siemens 3RT2617-1AK63 is a SIRIUS capacitor contactor in size S00, purpose-built for switching capacitor banks in power-factor correction (PFC) panels. Its AC coil, screw-type terminals, and 45 mm width make it a direct fit for standard 35 mm DIN rail (DIN EN 50022) enclosures where space is tight — the S00 frame keeps the footprint compact at 125 mm tall by 120 mm deep. Rated for capacitor switching at 230 V AC (6 A), 400 V AC (3 A), and 690 V AC (1 A), it handles the inrush currents typical of discharged capacitor banks without welding contacts — the arcing time of 10 to 15 ms and AC switching time of 4 to 15 ms are tuned for that duty.
The headline numbers — 6 A at 230 V AC, 3 A at 400 V AC, 1 A at 690 V AC — are the capacitive load ratings, not the general-purpose AC-1 or AC-3 motor ratings you see on standard contactors. Capacitor contactors must handle higher peak inrush (often 20–30× rated current for a few milliseconds) without contact bounce or welding. The SIRIUS design addresses this with dedicated damping resistors or pre-charge circuits integrated into the contactor block; the 3RT2617-1AK63 is rated for a maximum of 180 switching cycles per hour across the entire voltage range from 230 V to 690 V, which matches typical PFC step-switching intervals.
Screw-type terminals accept solid or stranded conductors: 2× (0.5 to 1.5 mm²), 2× (0.75 to 2.5 mm²), or 2× 4 mm². At 40 °C ambient, the terminal rating allows 1× 4 mm² or 2× 2.5 mm²; at 60 °C, 2× 4 mm² is permitted.