SIRIUS S3 power contactor — 58 A AC-3e at 690 V
The Siemens 3RT5046-1AL20 is a SIRIUS S3-frame power contactor rated for 58 A in AC-3e duty at 690 V, which means it handles motor switching up to that current in standard induction-motor starts — the rating that governs real panel fit, not the higher AC-1 resistive number. Screw-type terminals on the main circuit accept 2x (2.5 … 16 mm²) solid or stranded, sized for the S3 frame's current draw. Coil pickup at 24 V draws 6 A inrush (holding current lower); at 230 V the inrush is also 6 A, so the control transformer sizing is straightforward. Side-by-side mounting is permitted, so panel density is up to the thermal derating — the 60 °C ambient derate for the main conductors is 35 mm² minimum (vs 50 mm² at 40 °C).
Motor power at 60 °C ambient
At 60 °C ambient the contactor delivers 38 kW at 230 V, 66 kW at 400 V, and 114 kW at 690 V — these are the real-world motor ratings when the panel runs hot, not the ideal 40 °C numbers. If your BOM line calls for a 55 kW motor at 400 V in a warm enclosure, this contactor covers it with margin.
Switching frequency and mechanical endurance
Rated for 5 000 operating cycles per hour at AC, with a maximum of 900/h in AC-1, 850/h in AC-3/AC-3e, and 250/h in AC-4.