The Siemens 3RT1035-3AN60 is a SIRIUS S2 power contactor rated for motor switching at 22 kW on a 500 V 50 Hz line (AC-3 duty) and 18.5 kW at 400 V under AC-2 duty. The screw-type main terminals accept 2x (0.75... 25 mm²) stranded or 2x (0.25... 2.5 mm²) solid conductors, which covers the typical feed and motor cable for this frame size.
Side-by-side mounting is permitted, so multiple contactors can pack tightly in a panel without derating for spacing — useful when building a motor control centre row. Dimensions are 112 mm height, 55 mm width, and 115 mm depth.
Duty cycles and endurance
Electrical switching frequency varies by duty: 1 200 cycles/hour at AC-1 (resistive loads), 1 000 at AC-3 (squirrel-cage motors, starting and disconnecting running), and 300 at AC-4 (plugging, inching, reversing). The AC-4 limit is the one to watch for reversing or jogging applications — at 300 cycles/hour the contactor is designed for occasional reversing, not continuous inching duty. These timing figures are within the standard range for a contactor of this frame and inform the coordination with upstream short-circuit protection.
Environmental limits
The -25 °C lower operating limit means it can be installed in unheated plant areas in most temperate climates without auxiliary heating, but verify the panel's internal temperature rise under full load stays below +60 °C.