What it is and where it fits
The Siemens 3RT2018-1AR62 is a SIRIUS power contactor in Size S00 — the smallest frame in the SIRIUS family, built for switching motor loads and resistive loads inside control panels. It mounts on a 35 mm DIN rail per DIN EN 60715 using either the integrated snap-on clips or screws, so it lands in the same rail as your motor starters and distribution blocks. Rated for AC-3 duty at 750 switching cycles per hour, this contactor handles the repetitive inrush of induction motors on conveyors, pumps, and compressors. The AC-1 resistive load rating goes to 1 000 cycles/h, while AC-4 (plugging/reversing) is limited to 250 cycles/h — a useful derating guide if you are jogging or inching a load.
Panel fit and wiring
Dimensions are 45 mm wide, 58 mm high, and 73 mm deep — the S00 footprint leaves room for side-by-side auxiliary contact blocks and overload relays on the same DIN rail. Clearance around the contactor: 10 mm upward, 10 mm forward, 10 mm downward, and 6 mm to the side. That 6 mm side gap is tight; if you are packing multiple contactors in a row, verify the auxiliary block width before finalizing the rail layout. Screw-type terminals on the magnet coil accept solid or stranded wire from 0.5 to 4 mm², with dual-wire entries for paralleled control wiring. The main contact terminals accept 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or 2x 4 mm² — enough for the load-side motor leads on a Size S00 contactor.
Mounting flexibility and operating conditions
The contactor can be rotated ±180° on a vertical mounting surface and tilted forward or backward by ±22.5° — useful when the panel layout forces an odd angle or when you are retrofitting into an existing enclosure without re-drilling the backplate. Operating temperature range is -25 to +60 °C, storage range -55 to +80 °C. The storage limit is broader because the part is not energized — handling and shipping conditions are what that lower bound governs.