What it is and where it fits
The Siemens SIRIUS 3RT2025-2CK64-3MA0 is a power contactor in the size S0 frame, designed for switching motor loads and resistive loads in industrial control panels. It mounts on a 35 mm DIN rail per DIN EN 60715, with screw and snap-on fastening, and the magnet coil uses spring-type terminals for quick wiring.
Key ratings and what they mean for fit
The coil is rated for 24 VDC, drawing 6 A at the rated value — this is the inrush holding current, not the continuous coil consumption, so verify the control transformer or DC supply can deliver that peak without droop. The contactor is rated for switching frequencies up to 1 000 cycles per hour under AC-1, AC-2, AC-3, and AC-3e duty, and 300 cycles per hour under AC-4 (the most demanding motor braking/reversing duty). That 1 000 cycles/h limit means it can cycle every 3.6 seconds continuously — fine for conveyor start/stop, tight for rapid jogging. Auxiliary contact ratings are provided for DC switching at several voltages: 6 A at 24 V, 2 A at 48 V and 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, 3 A at 400 V, and 0.6 A at 440 V. These are the maximum breaking currents for the auxiliary contacts in DC circuits — inductive loads (relays, contactor coils) will need derating or a free-wheel diode across the load. The contactor measures 102 mm high, 45 mm wide, and 144 mm deep — the 45 mm width is the standard S0 footprint, so it occupies one 45 mm slot on the DIN rail. Operating temperature range is -25 to +60 °C, storage range -55 to +80 °C. The mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, giving flexibility in tight cabinets. Wire sizes accepted: solid or stranded 1 to 10 mm², and 2x (0.5 to 2.5 mm²) for paralleled conductors. The spring-type terminals on the coil side reduce wiring time compared to screw clamps, but require a screwdriver for release — not tool-less push-in.