What it is and where it fits
The Siemens SIRIUS 3RT2018-2EP01 is a size S00 power contactor, part of the SIRIUS family, designed for switching motor loads and resistive loads in industrial control panels. Its 45 mm width and 73 mm depth fit standard 35 mm DIN rail per DIN EN 60715, with screw and snap-on mounting. It carries a 24 VDC coil and spring-type terminals for the magnet coil, eliminating the need for screwdriver torque checks on that connection.
Key ratings and what they mean for the panel
Rated switching capacity at 24 V is 10 A, so it handles typical 24 VDC control circuits and small motor loads without derating. At 400 V AC the switching capacity is 3 A, which covers smaller three-phase motor circuits up to that voltage. Mechanical switching frequency varies by duty class: up to 1 000 operations per hour under AC-1 resistive loads, 750 ops/h under AC-3 motor starting, and 250 ops/h under AC-4 plugging/reversing. That means the part is suited for moderate-cycle applications — a conveyor start/stop station, not a high-speed pick-and-place. Operating temperature range is -25 to +60 °C, which covers most indoor panel environments. Storage range extends to -55 to +80 °C, relevant for unheated warehouses. The contactor includes an integrated auxiliary switch, saving a separate add-on block for basic status feedback.
Mounting and wiring constraints
Mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, so it fits awkward panel layouts without special brackets. Clearance requirements: 10 mm upward, 10 mm forward, 10 mm downward, and 6 mm at the side. Wire terminals accept solid or stranded conductors from 0.5 to 4 mm², and up to 2x (0.5 to 4 mm²) for paralleled feeds.