The Siemens SIRIUS 3RT5045-1AQ00 is a size S3 power contactor built for switching motor loads in control panels. It measures 70 mm wide by 146 mm tall by 139 mm deep, fitting a standard DIN-rail footprint with screw and snap-on mounting onto 35 mm or 75 mm rail. Rated for 21.1 kW at 690 V, this contactor handles motor duty up to that power level. The insulation voltage is rated at 1 000 V, giving headroom for 690 V line applications. At 60 °C ambient, the power rating derates to 38 kW at 230 V, 66 kW at 400 V, and 114 kW at 690 V — the thermal curve matters if the panel runs hot.
Mounting and integration
Mounts via screw or snap-on onto 35 mm and 75 mm DIN rail. Side-by-side mounting is allowed, so you can pack multiple contactors without spacing. The mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward — useful when orienting the panel for cable entry. Main circuit terminals are screw-type, accepting 2x (2.5... 16 mm²) solid or stranded, or 2x (10... 1/0) AWG. Auxiliary and control circuits also use screw terminals. An auxiliary switch extension is available as an add-on.
Lifecycle and sourcing
Compliance documentation includes RoHS and REACH substance prohibitance dated 03/01/2017. The contactor carries a degree of pollution rating of 3, suitable for industrial environments.