What this part is and where it fits
The Siemens SIRIUS 3RT2018-2FB41 is a size S00 power contactor with a 24 V DC coil and spring-type terminals for the magnet coil connection. It mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 60715, making it a standard panel-building component for motor control centers and distribution boards.
Key ratings and what they mean for your panel
The 24 V DC coil is rated for a 10 A switching capacity at the same voltage, so it can handle moderate DC loads like small DC motors or solenoid valves directly. For AC loads, the contactor is rated 2 hp at 230 V and 3 A at 400 V — useful for fractional-horsepower pumps or small conveyor drives. Switching frequency limits depend on the duty class: 1,000 operations per hour at AC-1 (resistive loads), 750 per hour at AC-2 and AC-3 (motor starting/running), and 250 per hour at AC-4 (plugging or inching). The AC-3e rating also allows 750 ops/hour for energy-efficient motors. These numbers tell you the contactor can keep up with a fast-cycling packaging line but needs derating for heavy inching duty. Mechanical life is typical 30 million cycles, with main contact electrical life between 20 and 12 million cycles depending on load. That puts this in the workhorse category for a panel that sees regular but not continuous switching — think batch processing rather than a 24/7 conveyor.
Mounting and wiring details
The contactor accepts solid or stranded wire from 0.5 to 4 mm², and can take two conductors per terminal in the same range. Spring-type terminals on the coil mean no screw tightening — just strip to 8 mm and push in. The mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, so it fits odd panel layouts. Clearance distances: 10 mm upwards, forwards, and downwards; 6 mm at the sides. That's tight enough for a crowded DIN rail but leaves room for wiring ducts if you plan ahead.