The Siemens 3RT2045-1AL00 is a SIRIUS power contactor in size S3, rated for 77 A at 480 V in AC-3 duty — that is the motor-switching current, meaning it handles a 3-phase induction motor load up to that full-load current without derating. It mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715, with a 70 mm width and 152 mm depth that fits standard panel layouts. The contactor includes an auxiliary switch and accepts solid conductors from 2.5 to 16 mm² on the main circuit.
Mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, giving flexibility in tight enclosures. Minimum clearances: 10 mm upward, 10 mm downward, 20 mm forward, 10 mm at the side — plan your DIN-rail spacing accordingly. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C.