What it is and where it lands
The Siemens 3RT2025-1AU00 is a SIRIUS S0 power contactor — the S0 frame is the workhorse size for light-to-medium motor and resistive loads in control panels. Screw-type terminals on the magnet coil, a built-in auxiliary switch, and a 45 mm width that fits standard DIN-rail spacing. Mounting is screw and snap-on onto 35 mm DIN rail per DIN EN 60715, so it drops into any panel that already carries SIRIUS gear.
What the ratings mean for fit
The headline motor rating is 14 A at 480 V and 3 hp at 230 V. That 14 A AC-3 figure is the one that governs switching a three-phase induction motor — it's the current the contactor can make and break under load across the full motor start cycle. For resistive or heating loads (AC-1), the contactor will handle more current, but the AC-3 number is what you size against for a pump, fan, or conveyor. The auxiliary contact is rated 10 A at 24 V, 2 A at 48/60 V, and derates further up to 0.3 A at 220 V — enough for a PLC input or a pilot light, but not for switching another contactor coil directly at higher voltages without checking the inrush.
Panel fit and wiring
Dimensions are 45 mm wide, 85 mm high, 97 mm deep. The 97 mm depth is the body only — add clearance for the screw terminals and any right-angle wiring. Clearances around the contactor: 10 mm upwards, forwards, and downwards, 6 mm at the sides. That side clearance is tighter than the vertical, so when you're packing multiple contactors side-by-side on the DIN rail, the 6 mm gap is the limiting factor. Wire range accepts 1 to 10 mm² solid or stranded, and the terminal can take two conductors per clamp: 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²). The mounting position is flexible — +/-180° rotation on a vertical surface, and can tilt forward/backward by +/-22.5° — handy when you're working into a tight enclosure corner.
Operating conditions and lifecycle
Runs from -25 to +60 °C during operation, stores from -55 to +80 °C. The mechanical life of the contactor is typical 10 million operations. Electrical life depends on the load: 1,000 operations per hour at AC-1, AC-2, AC-3, and AC-3e, dropping to 300 per hour at AC-4 — the heavy-duty plugging and inching duty. The lifecycle stage is listed as current production. This is a standard catalog part, not a phase-out or last-time-buy item. It's sourced and quoted to order against an RFQ through independent distribution; availability and current pricing are confirmed at quote time.