SIRIUS S2 Power Contactor with 110 V AC Coil
The Siemens SIRIUS 3RT1035-1XF40-0LA2 is a size S2 power contactor designed for switching motor loads in industrial control panels. It mounts on a 35 mm DIN rail per DIN EN 50022, with screw and snap-on fastening. The coil is rated for 110 V AC, picking up at 70% of rated voltage and dropping out at 125% of rated value.
Motor Switching Capacity and Duty Cycles
This contactor is rated for 22 kW at 500 V in AC-3 duty (standard motor switching) and 11.4 kW at 690 V. For AC-2 duty (slip-ring motor starting) at 400 V, it handles 18.5 kW. These ratings define the motor load it can switch reliably — the AC-3 figure is the one to match against your motor nameplate for standard induction motors. Switching frequency varies by duty: up to 1 200 operations per hour for AC-1 resistive loads, 1 000/h for AC-3 motor loads, 600/h for AC-2, and 300/h for AC-4 (plugging/inching). The mechanical service life is rated at 10 000 000 operations typical.
Auxiliary and DC Switching Capability
The contactor carries zero instantaneous auxiliary contacts (no built-in aux), so any auxiliary switching requires a separate add-on block. For DC loads, it is rated at 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V — these are the maximum breaking currents for DC circuits, which are significantly lower than AC ratings due to arc extinction characteristics. AC load switching is rated at 6 A at 230 V and 3 A at 400 V. Closing time on DC is 20 to 25 ms, with an arcing time of 10 to 15 ms.
Termination and Wiring
Main circuit connections use screw-type terminals. Solid conductors: 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²), max 2x (0.75 to 4 mm²). Stranded conductors: 2x (0.75 to 25 mm²). For the main circuit at maximum AC-1 rating, the terminal accepts up to 16 mm². Solid or stranded combinations: 2x (0.75 to 16 mm²). These ranges cover typical panel wiring from control to power circuits.
Physical Dimensions and Mounting Clearances
Dimensions: 55 mm width, 142 mm height, 130 mm depth. Side-by-side mounting is permitted, which saves panel space. Required clearances for arc venting: 10 mm upwards, 10 mm forwards, 10 mm downwards, and 10 mm at the side. The 55 mm width is the standard S2 footprint — check your panel layout against this dimension.