Siemens SIRIUS 3RT1045-1AD04 — Power Contactor, Size S3
The Siemens SIRIUS 3RT1045-1AD04 is a Size S3 power contactor rated for 45 kW at 400 V in AC-3 duty, making it the primary spec for switching standard three-phase induction motors — pumps, fans, compressors — up to that load. It also carries a 37 kW rating at 400 V in AC-2 duty, which covers slip-ring motor starting, and a 66 A rating in AC-4 for reversing or inching applications where the contactor makes and breaks the motor at full current. Side-by-side mounting is permitted, which saves rail space in dense cabinets. The main circuit uses screw-type terminals, and the control circuit accepts solid wire from 2x (0.5... 1.5 mm²) up to max 2x (0.75... 4 mm²), with stranded going up to 2x (10... 50 mm²). The enclosure is rated IP20 on the front with cover or box terminal; the terminal itself is IP00, so it's meant for installation inside a panel, not exposed to washdown. Operating temperature range is -25 to +60 °C, storage from -55 to +80 °C, and the degree of pollution is 3, meaning it's suitable for industrial environments with conductive dust or occasional condensation.
Substance prohibitance date is 05/01/2012.
Dimensions & Wiring
Height 146 mm, width 70 mm, depth 188 mm. Control circuit ratings: at 24 V rated value 10 A, at 60 V 2 A, at 110 V 1 A, at 220 V 0.3 A, at 230 V 6 A, at 400 V 3 A. These are the contact ratings for the auxiliary or control contacts — match your PLC output or relay driver to the coil draw at your control voltage. Mechanical endurance is typical 10,000,000 operations. Electrical endurance varies by duty: at AC-1 maximum 900 operations/hour, AC-2 maximum 400, AC-3 maximum 1,000, AC-4 maximum 300. These are fast enough for most motor control circuits but may need coordination with upstream short-circuit protection devices for selectivity.