SIRIUS power contactor, size S3 — 55 kW at 500 V AC-3
The Siemens 3RT1046-1AN20 is a SIRIUS power contactor in size S3, rated for 55 kW at 500 V AC-3 (50 Hz) and 25.4 kW at 690 V AC-3. The main circuit uses screw-type terminals accepting stranded conductors up to 2x 50 mm². It mounts via screw or snap-on onto 35 mm or 75 mm standard DIN rail.
Duty ratings and switching frequency
Maximum switching frequency varies by duty: 900 operations per hour at AC-1 (resistive), 850 ops/h at AC-3 (squirrel-cage motor starting), 350 ops/h at AC-2 (slip-ring motor), and 250 ops/h at AC-4 (plugging/inching). The AC-3 rating is the one that governs motor-switching applications — 850 ops/h is typical for a contactor this size, so it handles frequent conveyor or pump starts without derating.
Environmental and mounting
Operating temperature range is -25 to +60 °C; storage from -55 to +80 °C. Pollution degree 3 (conductive pollution, typical for industrial control panels). The front is rated IP20 with cover or box terminal; the terminal body itself is IP00. Side-by-side mounting is permitted without derating — useful when packing multiple contactors into a motor control center.
Auxiliary contact ratings
Built-in auxiliary contacts handle 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 0.3 A at 220 V DC. The DC switching curve drops off with voltage — at 60 V it's still 2 A, but at 220 V it's down to 0.3 A. That matters if you're switching DC control coils or indicator loads at higher voltages.