What it is and what it does
The Siemens 3RT1045-1AR64 is a SIRIUS power contactor in the Size S3 frame, designed for switching motor loads and resistive loads in industrial control panels. It mounts on 35 mm or 75 mm DIN rail via screw and snap-on fastening, so it integrates into standard enclosure layouts without special brackets. Rated for 45 kW at 500 V and 21.1 kW at 690 V, it handles the motor power range typical of medium-duty conveyors, pumps, and compressors. The coil accepts 400 V at 50 Hz or 400–440 V at 60 Hz. Mechanical life is rated at 10,000,000 operations typical, and maximum switching frequency reaches 1,000 1/h under AC-3 duty. That means it can cycle a motor start every 3.6 seconds continuously — realistic for high-throughput packaging or material-handling lines.
Termination and wiring
Main current circuit uses screw-type terminals. Solid conductors accept 2x (0.5–1.5 mm²), 2x (0.75–2.5 mm²), or max 2x (0.75–4 mm²); stranded conductors accept 2x (10–50 mm²). That covers both control wiring and power tails without adapter lugs. The front face carries an IP20 rating with the cover or box terminal installed; the terminal body itself is IP00. Pollution degree 3 means it tolerates conductive dust and condensation typical of industrial environments. Side-by-side mounting is permitted, which helps when packing multiple contactors into a tight row on the DIN rail.
Key ratings at a glance
Dimensions: 146 mm height, 70 mm width, 188 mm depth. Operating temperature range –25 to +60 °C; storage range –55 to +80 °C. Arcing time at AC is 10–25 ms. Rated switching frequencies: AC-1 max 900 1/h, AC-2 max 400 1/h, AC-3 max 1,000 1/h, AC-4 max 300 1/h (–).