What it is and what it does
The Siemens 3RT2018-2AP61 is a SIRIUS power contactor in the compact S00 frame, designed for switching motor loads and resistive circuits in industrial control panels. It carries a 24 VDC coil with spring-type terminals and is rated for 10 A at 24 V and 2 hp at 230 V, making it a fit for small motor starters and general switching duties.
Key ratings and what they mean
The contactor is rated for AC-3 duty at 750 operating cycles per hour, which is the standard for starting squirrel-cage motors and disconnecting them under load — so it handles frequent start/stop cycles on conveyors or pumps without overheating the contacts. For resistive loads (AC-1), it can cycle up to 1000 times per hour, and for plugging or inching (AC-4), the rate drops to 250 cycles per hour because the contact wear is higher. Mechanical life is rated at 30 million operations typical, which means the contactor itself will outlast most applications before the spring or armature wears — the electrical life depends on the load and switching frequency. The coil draws 0.24 A at both 50 Hz and 60 Hz, so it works across mains frequencies without derating. Operating temperature range is -25 to +60 °C, with storage from -55 to +80 °C — fine for most indoor panel environments.
Mounting and integration
Mounts via screw or snap-on onto a 35 mm DIN rail per DIN EN 60715. The size S00 footprint is 45 mm wide, 70 mm high, and 73 mm deep — a common compact format that fits alongside other S00 contactors and overload relays in a standard panel layout. Mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward or backward, giving flexibility in tight enclosures. Clearance requirements: 10 mm upwards, 10 mm forwards, 10 mm downwards, and 6 mm at the side — these are the minimum air gaps needed for heat dissipation and arc quenching. The spring-type terminals on the coil accept solid or stranded wire from 0.5 to 4 mm², and the main contacts also accept 2x (0.5 to 4 mm²) solid or stranded, so no special ferrules are required for standard panel wiring.