What it is and what it does
The Siemens SIRIUS 3RT2018-2AV02 is a size S00 power contactor with a 24 VDC coil, designed for switching motor loads and resistive loads in control panels. It mounts on 35 mm DIN rail per DIN EN 60715 via screw or snap-on fastening, and the mounting position allows +/-180° rotation on a vertical surface plus +/-22.5° tilt forward and backward.
Key ratings and what they mean for fit
The contactor is rated for AC-3 duty at 750 operations per hour maximum, which means it can switch motor loads under typical starting conditions at that rate without overheating. AC-4 duty is limited to 250 ops/hr, reflecting the more severe arc wear from reversing or inching. Mechanical life is quoted at 30,000,000 operations typical. Auxiliary switching capacity is given for multiple voltage levels: 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, 3 A at 400 V, and 0.2 A at 440 V. At 230 V the motor rating is 2 hp. These figures define the maximum make/break capability for control circuits at those voltages. The coil connection uses spring-type terminals, and the main contact wiring accepts solid or stranded conductors from 0.5 to 4 mm², or 2x (0.5 to 4 mm²) for paralleled feeds. This covers common control and power wiring sizes in European panels.
Integration and spacing
Physical dimensions: width 45 mm, height 70 mm, depth 73 mm. Required clearances: 10 mm upward, 10 mm downward, 10 mm forward, and 6 mm at the side. These are the minimum air gaps for heat dissipation and arc containment — account for them when laying out the DIN rail in the enclosure. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C. The arcing time is 10 to 15 ms at AC, with a make time of 4 to 15 ms at AC. At 50 Hz and 60 Hz the rated operational current is 0.25 A.