Siemens SIRIUS 3RT2045-1XF40-0LA2 — Size S3 Contactor with 110 VDC Coil
The Siemens SIRIUS 3RT2045-1XF40-0LA2 is a Size S3 contactor designed for switching motor loads in industrial control panels. It carries a 110 VDC coil with screw-type terminals, rated for continuous duty. Main contact ratings reach 77 A at 480 V and 62 A at 600 V, making it suitable for medium-horsepower motor circuits in North American and IEC installations. Mounting is flexible: screw-fixed or snap-on onto a 35 mm standard mounting rail per DIN EN 60715. The contactor can be rotated ±180° on a vertical mounting surface and tilted forward/backward ±22.5°, giving panel builders room to fit tight enclosures. Dimensions are 140 mm height, 70 mm width, and 152 mm depth — the depth is the key dimension to check for enclosure depth clearance, especially when paired with overload relays or auxiliary contact blocks that add to the stack.
Coil & Auxiliary Details
The coil is 110 VDC, with a pickup threshold starting at 70% of rated voltage and an inrush peak of 1.5 A. It includes an auxiliary switch as standard, which can be used for status feedback or interlocking in safety circuits. Operating temperature range is -40 to +70 °C, with storage from -55 to +80 °C — wide enough for unheated enclosures or outdoor cabinets in moderate climates.
Integration & Panel Fit
Screw and snap-on mounting onto 35 mm DIN rail per DIN EN 60715. The contactor accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded wire at the main terminals. Clearance distances: 10 mm upwards, 20 mm forwards, 10 mm downwards, 10 mm at the side — plan the enclosure layout accordingly.