What it is and what it does
The Siemens SIRIUS 3RT2035-3CL24-3MA0 is a Size S2 power contactor rated 40 A at 480 V, built for switching motor loads and resistive circuits in industrial control panels. It mounts via screw or snap-on onto standard 35 mm DIN rail per DIN EN 60715, with a width of 55 mm that fits one standard modular slot. The spring-type terminals on the magnet coil accept 2x (0.5 to 2.5 mm²) solid or stranded wire, so no screwdriver is needed for the coil connection — useful when you're wiring a panel fast or swapping one out on site.
Key ratings and what they mean for fit
The headline rating is 40 A at 480 V, which means this contactor can handle a 40 A resistive load at that voltage, or a motor load within its AC-3 duty cycle. The mechanical life is rated at 10,000,000 operations typical, so it's built for high-cycle applications like conveyors or pumps. Operating temperature range is -25 to +60 °C, and storage range is -55 to +80 °C. The mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, which helps when you're squeezing it into a tight enclosure.
Clearance and spacing
Minimum clearances: 10 mm upwards, 10 mm forwards, 10 mm downwards, and 6 mm at the side. At 178 mm deep and 114 mm tall, it needs a panel depth of at least 188 mm to the cover. The 55 mm width means you can fit about 17 of these per meter of DIN rail, but leave the side gap for heat dissipation.
Switching performance and coil data
Arcing time is 10 to 20 ms, and the make/break time at AC is 10 to 18 ms. The coil draws 0.36 A at 50 Hz and 0.39 A at 60 Hz at 230 V rated value. Maximum operating frequency varies by duty: 1,200 operations per hour at AC-1, 750 at AC-2, 1,000 at AC-3, and 300 at AC-4. The auxiliary switch is not included on this variant — it's a bare main contactor with 18 to 1 main contacts.