SIRIUS S3 Power Contactor — 3RT5046-1AC20
The Siemens 3RT5046-1AC20 is a SIRIUS S3 power contactor rated for motor loads up to 25.4 kW at 690 V, with an AC-3e maximum operating voltage of 1,000 V. This is the class-defining rating: it tells you the contactor can switch a 25.4 kW induction motor at 690 V under AC-3 duty (starting, stopping, and reversing under load).
Thermal and Switching Performance
Rated switching frequency reaches 5,000 operations per hour at AC, with AC-3 maximum at 850 1/h and AC-4 at 250 1/h. The AC-3e maximum matches the AC-3 figure at 850 1/h, confirming the contactor handles the same cycle rate for both standard and enhanced AC-3 duty. The contactor delivers 38 kW at 230 V, 66 kW at 400 V, and 114 kW at 690 V when operated at 60 °C ambient. These derated values are the ones to use for continuous-duty sizing in warm environments.
Substance prohibitance compliance date is March 1, 2017, aligning with RoHS and REACH requirements. The contactor carries the SIRIUS brand and is designed for main current circuits with screw-type terminals.
Main circuit terminals accept solid or stranded conductors: 2x (2.5 to 16 mm²) or 2x (10 to 1/0 AWG). Minimum permissible conductor cross-section at 40 °C is 50 mm²; at 60 °C it derates to 35 mm². Auxiliary contact switching capacities: 6 A at 24 V, 1 A at 110 V, 0.3 A at 220 V, 6 A at 230 V, and 3 A at 400 V. These ratings define the signal-level loads the built-in aux contacts can handle without external interposing relays. Side-by-side mounting is permitted, allowing dense panel layouts without de-rating when the contactors are ganged.
Envelope dimensions: 70 mm width, 146 mm height, 139 mm depth. The S3 frame size is the physical footprint identifier for DIN-rail and back-panel planning.