SIRIUS S3 power contactor for motor loads
The Siemens 3RT1045-1AQ60 is a SIRIUS S3-size power contactor rated for 45 kW at 500 V AC-3 and 21.1 kW at 690 V AC-3, switching motor loads in industrial control panels. It mounts via screw fixing or snap-on onto 35 mm and 75 mm standard mounting rail, fitting directly into a DIN-rail enclosure layout. The main current circuit uses screw-type terminals accepting stranded conductors up to 2x (10... 50 mm²), sized for the S3 frame's current-carrying capacity.
Duty-cycle limits and thermal budget
Switching frequency depends on duty class: 1 000 cycles/hour under AC-3 (motor start/run), 900 cycles/hour under AC-1 (resistive), 400 cycles/hour under AC-2, and 300 cycles/hour under AC-4 (plugging/inching). Arcing time spans 10 to 15 ms at AC, with a pick-up dropout range of 10 to 25 ms — relevant for coordination with upstream protective devices. Operating temperature range is -25 to +60 °C; storage range extends to -55 to +80 °C. Pollution degree 3 rating suits it for industrial environments with conductive dust or moisture.
Auxiliary contact ratings and wiring
Built-in auxiliary contacts are rated for 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V — covering control-circuit voltages common in 24 VDC and 230 VAC panels. Solid and stranded wire cross-sections accepted: 2x (0.5... 1.5 mm²) and 2x (0.75... 2.5 mm²) for solid, up to 2x (2.5... 16 mm²) for stranded or solid, plus 2x (10... 50 mm²) for main circuit stranded.