What it is and where it fits
The Siemens 3RT2018-1TP01-0RA0 is a SIRIUS power contactor in the size S00 frame — the smallest footprint in the SIRIUS family, designed for switching motor loads and resistive loads in control panels. It snaps onto 35 mm DIN rail per DIN EN 60715 or screws directly to a mounting plate, occupying a 45 mm width slot. The 73 mm depth keeps it clear of deeper busbars or terminal blocks in a typical 200 mm deep enclosure. Screw-type terminals on the magnet coil and main contacts accept solid or stranded wire from 0.5 mm² up to 4 mm², with dual-wire capability for looping through control wiring without an extra junction block. The auxiliary switch is built in, saving a DIN slot that a separate auxiliary contact block would occupy.
What the switching rates tell you
The contactor is rated for 1 000 operations per hour in AC-1 duty (resistive loads like heaters), 750 per hour in AC-3 (squirrel-cage motor starting), and 250 per hour in AC-4 (plugging or inching). The AC-3 rate is the one that matters for most conveyor, pump, and fan applications — it means the contactor can start a motor every 4.8 seconds continuously without exceeding thermal limits. AC-4 at 250/h reflects the higher arc energy during reversing or jogging cycles. Mechanical life is rated at 3 000 000 operations typical — the contactor itself will outlast the driven equipment in most panel designs. The arcing time sits between 10 and 15 ms at AC, which is consistent with a standard contactor design; no forced arc-chute extinction needed.
Mounting and environment
The contactor can be mounted in any orientation: +/-180° rotation on a vertical surface, and tilted forward or backward by +/-22.5°. Clearance requirements are 10 mm upwards, 10 mm forwards, 10 mm downwards, and 6 mm at the sides — tight enough for a dense DIN rail array. Operating temperature range is -25 to +70 °C, storage from -55 to +80 °C, so it handles unheated warehouses and panel heat rise without derating.