What it is and where it lands
The Siemens SIRIUS 3RT2346-1NB30-4AA0 is a size S3 contactor with a 20-33 V AC/DC coil, screw-type coil terminals, and an integrated auxiliary switch. It mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715 — standard panel integration for a control cabinet. The mounting position is flexible: +/-180° rotation on a vertical surface, plus +/-22.5° tilt forward/backward, so it fits tight layouts without derating worries.
What the ratings mean for fit
The coil pulls 3.5 VA at both 50 Hz and 60 Hz, with a 6.5 A inrush peak — that's a modest control-transformer load, so you can gang several on a single 24 VDC supply without oversizing it. The coil holds from 20 V up to 33 V (AC or DC), with a dropout threshold around 80% of rated (0.8 initial value) and a 1.1x full-scale overvoltage tolerance. Opening time is 38-57 ms for both AC and DC; arcing time runs 10-20 ms. That's a standard contactor response — fast enough for motor starting, not for a safety pulse. Main contact ratings are given as 10-2 (likely a thermal current / utilization category shorthand — check the full datasheet for AC-3 vs AC-1 values). The auxiliary switch is included and carries its own ratings: 10 A at 24 V, 6 A at 60 V, 2 A at 48 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, and 6 A at 230 V. That covers most control-voltage levels you'll see in a panel — 24 VDC, 120 VAC, 230 VAC — so the aux contacts can drive PLC inputs or pilot lights without an interposer relay. Mechanical life is rated at 10 million cycles typical — that's a long service interval for a panel contactor; you'll replace the coil or the load before the mechanism wears out. Operating temperature spans -25 to +60 °C, storage from -55 to +80 °C, so it handles unheated warehouses and hot cabinet interiors.
Wiring and panel fit
Power wiring accepts stranded conductors from 6 to 70 mm² — that's a wide range, covering everything from a 4 mm² motor feed up to a 50 mm² bus. The coil and auxiliary terminals take solid wire 0.5-1.5 mm² or stranded 0.75-2.5 mm², with two conductors per terminal. That's the standard spring-cage or screw-clamp range for control wiring. Clearance distances: 10 mm upwards, 10 mm downwards, 10 mm at the side, 20 mm forwards — tight enough for a crowded DIN rail, but leave the forward gap for arc-chamber venting. Dimensions: 140 mm high, 96 mm wide, 152 mm deep. That's a size S3 footprint — roughly 4 inches wide, so it takes up one standard 96 mm DIN-rail slot. Two auxiliary contact blocks can be attached (attachable = 2), expanding the control interface without widening the footprint.