What it is and where it fits
The Siemens 3RT2025-1AC24 is a SIRIUS power contactor in the Size S0 frame, built for switching motor loads and resistive loads in control panels. It uses a 24 VAC magnet coil with screw-type terminals for the coil connection. The contactor is rated for AC-3 duty switching at up to 1,000 operating cycles per hour, which covers standard three-phase induction motor starts across conveyors, pumps, and fans.
Mounting and integration
Mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 60715. The 45 mm width and 85 mm height fit standard panel layouts. Mounting position is flexible: +/-180° rotation on a vertical surface, and can be tilted forward/backward by +/-22.5° on a vertical surface. Clearance requirements: 10 mm upwards, downwards, and forwards; 6 mm at the side. The Size S0 frame means it shares the same footprint as other S0 contactors and overload relays in the SIRIUS family.
What the ratings mean for your panel
The 24 VAC coil draws 0.25 A at 50 Hz and 0.28 A at 60 Hz — check your control transformer sizing, especially if multiple contactors pick up simultaneously. Operating temperature range is -25 to +60 °C, storage from -55 to +80 °C, so it handles typical enclosure ambient without derating. The screw-type main terminals accept solid or stranded wire from 1 to 10 mm², and the coil terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²). Mechanical life is rated at 10,000,000 typical operations.