Integrator's take on the 3RT2035-3AK64-3MA0
The Siemens 3RT2035-3AK64-3MA0 is a SIRIUS power contactor in Size S2, built for switching motor loads and resistive circuits in control panels. It carries a 480 V rating at 40 A and handles 7.5 hp at 230 V. The spring-type terminals on the magnet coil save wire-prep time compared to screw clamps — no torque driver needed for the coil connections. Mounting is screw or snap-on onto 35 mm DIN rail per EN 60715, and the contactor can be rotated ±180° on a vertical surface or tilted ±22.5° forward/backward, which helps when the panel layout is tight. Clearance distances are 10 mm upward, forward, and downward, 6 mm at the side — factor those into your gland-plate and busbar planning.
Duty-cycle and switching rates
The contactor's maximum switching rates vary by duty class: 1,200 operations per hour at AC-1 (resistive), 750/h at AC-2, 1,000/h at AC-3 and AC-3e (motor starting), and 300/h at AC-4 (plugging/inching). For a conveyor line cycling at 30 starts per hour, that's headroom; for a high-speed press running 600 cycles per hour in AC-4, you'd hit the limit. Mechanical life is rated at 10 million operations typical.
Panel integration and wiring
Dimensions: 55 mm wide, 114 mm high, 178 mm deep. The 55 mm width is a single DIN-rail module footprint — fits standard 35 mm rail. Wire range for main contacts: 2x 0.5 to 2.5 mm² solid or stranded. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C. The arcing time is 10 to 20 ms, and the operating time (AC coil) is 10 to 18 ms — fast enough for most motor-starting sequences but not for semiconductor-grade switching.
Auxiliary contact ratings
The auxiliary switch block (not fitted on this variant —) is rated for 6 A at 24 V, 2 A at 48 V and 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, 3 A at 400 V, 0.6 A at 440 V. These are the contact ratings for the auxiliary circuit; if your application needs feedback to a PLC at 24 VDC, the 6 A rating gives plenty of margin for a typical 0.5 A load.