The Siemens 3RT1044-1AR60 is a SIRIUS size S3 power contactor rated for 37 kW at 500 V in AC-3 duty, meaning it handles the inrush and running current of a motor load up to that power level. Screw-type terminals on the main circuit accept 2x (10... 50 mm²) stranded wire, so it lands in a panel with standard ring or fork lugs. The 70 mm width and 146 mm height fit the S3 footprint on a 35 mm or 75 mm DIN rail, with side-by-side mounting permitted for multi-contactor assemblies.
Ratings and what they mean for the panel
AC-3 switching rate maxes at 1 000 operations per hour, so it cycles a conveyor or pump motor every 3.6 seconds without exceeding the thermal limit. AC-4 rate drops to 300 per hour — that is the plugging or inching duty cycle, where the contactor makes and breaks stalled-rotor current. Mechanical life is 10 000 000 operations typical, so the armature and spring set outlast most load-side components in a 24/7 line. Pollution degree 3 means the contactor tolerates conductive dust and humidity found in unsealed industrial enclosures.
Mounting and wiring
Screw and snap-on mounting onto 35 mm and 75 mm standard mounting rail. The front face carries IP20 protection with a cover or box terminal; the terminal body itself is IP00, so the panel enclosure provides the overall seal. Solid wire from 0.5 to 4 mm² on the control circuit, stranded up to 50 mm² on the main circuit. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C.