What It Is and Where It Lands
The Siemens 3RT2348-1NF30 is a SIRIUS contactor, size S3, built for switching motor loads and resistive loads in industrial control panels. It lands on a 35 mm DIN rail per DIN EN 60715, secured by both screw and snap-on fastening — so it stays put under vibration but still comes off for a swap without prying a whole row loose. The coil accepts AC or DC from 83 to 155 V, pulling 3.5 VA at both 50 and 60 Hz. That wide-range coil simplifies stocking — one part covers a spread of control voltages common in European and North American panels. Envelope is 140 mm high by 96 mm wide by 152 mm deep. The depth matters when you're routing wires past a gland plate or trying to squeeze a row of contactors into a shallow enclosure — 152 mm is not a shallow-mount part.
What the Ratings Mean for Fit
Main contacts accept stranded wire from 6 to 70 mm² — that's a heavy lug range, sized for the S3 frame's current handling. The auxiliary switch is built in, with contacts rated at 10 A at 24 V, 6 A at 60 V, 6 A at 230 V, and 3 A at 400 V. Those are the values that determine whether the aux can drive a PLC input or a pilot light at your panel voltage without an interposing relay. Mechanical life is listed at 10 million operations typical. That's a high-cycle figure — suitable for frequent start/stop applications like conveyor indexing or pump cycling, not just infrequent isolation. Operating temperature range is -25 to +60 °C, storage from -55 to +80 °C. The storage range is wider — that's the handling and shipping limit, not the running limit. The operating range covers most indoor panel environments, but if the contactor sits next to a furnace or a steam line, watch the ambient.
Mounting and Wiring Notes
Mounting position is flexible: +/-180° rotation on a vertical surface, and can be tilted forward/backward by +/-22.5°. That helps when the panel layout forces an odd angle, but the clearances are tight — 10 mm upwards, 10 mm downwards, 20 mm forwards, 10 mm at the side. Skimp on those and you lose airflow and arc clearance. Solid wire termination on the aux/coil terminals accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²). The coil terminals are screw-type — no spring cages here, so torque them to spec and avoid stranded whiskers shorting to the frame.