What It Is and Where It Fits
The Siemens 3RT2025-1DB40 is a SIRIUS power contactor in the S0 frame size, designed for switching motor loads and resistive loads in control panels. It mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 60715, so it drops into any standard panel layout without adapter plates. The coil is rated 24 VDC, pulling 6 A at rated voltage — that's the DC-13 switching capacity for the auxiliary contacts, not the main contact rating. For motor duty, the AC-3 switching frequency is rated at 1,000 operations per hour, meaning it handles frequent start/stop cycles on conveyors or pumps without overheating the coil or arc chamber. Operating temperature spans -25 to +60 °C, so it's fine inside a non-conditioned enclosure near a process line. Storage range is -55 to +80 °C, which covers most warehouse conditions.
Key Ratings and What They Mean for Fit
The 24 VDC coil draws 6 A at rated value — that's the inrush and holding current combined. If you're feeding it from a 24 VDC power supply, factor that into the supply budget; it's not a low-power PLC output coil. Wire termination accepts solid or stranded conductors from 1 to 10 mm², with screw-type terminals. For the auxiliary contact wiring, it accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded. That covers most control wiring gauges used in North American and European panels. The S0 frame size gives a width of 45 mm, height of 85 mm, and depth of 107 mm. The 107 mm depth is the key dimension for enclosure depth — verify your panel can clear that plus wiring space behind the door. Mounting position allows +/-180° rotation on a vertical surface and can be tilted forward/backward by +/-22.5°. Clearance requirements: 10 mm upwards, 10 mm forwards, 10 mm downwards, 6 mm at the side. That's tighter than some contactors — you can pack them closer on the rail.
Panel Integration Notes
Snap-on mounting onto 35 mm DIN rail per DIN EN 60715 means no tools needed for installation — push on, pull the latch to release. The screw terminals are front-accessible, so wiring is straightforward even in a dense panel. The contactor includes an auxiliary switch (built-in), so you don't need a separate add-on block for feedback to the PLC or status indication. That saves one DIN-rail slot and one wiring step.