The Siemens SIRIUS 3RT1045-1AD24 is a S3-frame power contactor rated for motor switching at 45 kW on a 500 V AC-3 supply and 21.1 kW at 690 V. The 24 V AC coil pulls in reliably across 0.8 to 1.1 times rated voltage at 50 Hz and 0.85 to 1.1 at 60 Hz.
The 70 mm width, 146 mm height, and 188 mm depth fit a standard S3 panel footprint. Side-by-side mounting is permitted, so multiple contactors pack tightly on the rail without mandatory spacing gaps. IP20 on the front with the cover or box terminal installed; the terminal body itself is IP00, meaning the wiring compartment expects enclosure protection from the panel.
Duty cycle and switching frequency
Switching frequency varies by duty class: 900 operations per hour at AC-1 (resistive), 400 at AC-2 (slip-ring motor), 1,000 at AC-3 (squirrel-cage motor starting), and 300 at AC-4 (plugging/inching). The arcing time sits between 10 and 25 ms at AC, with a typical 10–15 ms window.
Environmental range
That covers unheated plant floors and hot panel interiors near motor starters. The 24 V DC coil draws 10 A at rated voltage; at 60 V DC the switching capacity drops to 2 A, at 220 V DC to 0.3 A — typical for DC load breaking in control circuits.