SIRIUS S2 power contactor, 24 VDC coil, screw terminals
The Siemens 3RT1035-1BB44-ZX95 is a SIRIUS S2 power contactor with a 24 V DC coil and screw-type terminals for the main current circuit. It mounts on a 35 mm DIN rail per EN 50022 using either screws or the snap-on clip, and is rated for side-by-side mounting without derating when the ambient stays within -25 to +60 °C during operation. AC-3 motor switching at 500 V delivers 22 kW, and at 690 V it handles 11.4 kW. AC-4 at 400 V is rated 35 A for reversing or inching duty where the load is switched under full current. The mechanical life is 10 million operations typical, and the maximum switching rate at AC-3 is 1,000 cycles per hour — enough for most conveyor and pump cycling, but not for high-speed pick-and-place. Terminals accept 2x (0.75 to 2.5 mm²) solid or 2x (0.75 to 25 mm²) stranded, with a maximum of 2x (0.75 to 4 mm²) solid on the smaller pair. The front face carries IP20; the terminal area is IP00, so live parts are exposed once the enclosure door is open — standard for panel-mounted contactors.
Integration and mounting
The S2 frame measures 55 mm wide, 112 mm high, and 179 mm deep — fits standard 55 mm-wide contactor slots on a DIN rail. Screw and snap-on mounting onto 35 mm rail per DIN EN 50022; side-by-side mounting is permitted, so you can gang multiple contactors without spacing gaps. The arcing time is 10 to 15 ms; at DC the dropout time is 20 to 25 ms, which matters for coordination with upstream fuses or motor-protective breakers.
Auxiliary contact ratings
The built-in auxiliary contacts handle DC-13 loads at various voltages: 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V. For AC-15 control circuits they're rated 6 A at 230 V and 3 A at 400 V. These numbers govern the PLC output or relay it can drive directly — watch the DC-13 curve if you're switching solenoids or contactor coils in a 24 VDC control loop.