What it is and what it does
The Siemens SIRIUS 3RT2018-1AP01-2AA0 is a power contactor in the S00 frame size, designed for switching motor loads and resistive loads in industrial control panels. It carries a 2 hp rating at 230 V, making it a fit for small motors on pumps, fans, and conveyors. The contactor includes an auxiliary switch, so you don't need to add a separate block for basic status feedback. The S00 frame keeps the footprint tight at 45 mm wide, 58 mm tall, and 73 mm deep — it slides onto a 35 mm DIN rail per DIN EN 60715 with either screw or snap-on mounting. That's a standard panel integration; no special brackets needed.
Key ratings and what they mean for your panel
The contactor's switching frequency depends on the duty class. For AC-3 motor starting, it handles up to 750 operations per hour; for AC-4 inching or plugging, that drops to 250 per hour. That means if you're running a conveyor that cycles every few seconds, stay within the AC-3 limit. The mechanical life is 30 million operations, so the coil and armature will outlast most applications if the electrical load is kept within ratings. The auxiliary contact ratings are given at several voltages: 10 A at 24 V, 2 A at 48 V and 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, and 0.2 A at 440 V. These are the switching limits for the built-in auxiliary switch — use them to size your PLC input or relay coil draw. At 400 V the auxiliary is rated 3 A, which covers most contactor feedback circuits. Wire termination uses screw-type terminals on the coil and main contacts. The terminals accept solid or stranded wire from 0.5 to 4 mm², and you can double up two conductors per clamp (2x 0.5-1.5 mm², 2x 0.75-2.5 mm², or 2x 4 mm²). That helps when you need to daisy-chain control power without adding a terminal block.
Mounting and environment
Mounting position is flexible — the contactor can be hung on a horizontal surface or mounted vertically. Clearance distances are specified: 10 mm upwards, 10 mm forwards, 10 mm downwards, and 6 mm at the sides. These are the minimum air gaps to maintain for heat dissipation and arc quenching; don't cram it tighter in a dense panel. Operating temperature range is -25 to +60 °C, which covers most indoor panel environments. Storage range is wider at -55 to +80 °C, so it can sit in a warehouse or truck without issue. The coil hold power is 0.25 VA at both 50 Hz and 60 Hz — a light load on the control transformer.