What it is and where it fits
The Siemens 3RT1036-1AU04 is a SIRIUS power contactor, size S2, designed for switching motor loads in industrial control panels. It mounts via screw or snap-on onto a 35 mm DIN rail per EN 50022, and side-by-side mounting is supported, so you can pack multiple contactors in a row without derating for heat buildup. The front face is IP20, keeping fingers away from live terminals; the terminal area is IP00, meaning the wiring compartment expects enclosure protection.
Key ratings and what they mean for your load
The headline motor ratings: 30 kW at 500 V (AC-3 duty) and 22 kW at 400 V in AC-2 duty — that second one is the rating for slip-ring motors or soft-start applications where the contactor makes/breaks under reduced current. For heavy jogging or plugging, the AC-4 rating at 400 V is 41 A, which is the figure to watch if your application involves frequent inching or reversing. The contactor also handles resistive loads (AC-1) up to the same thermal current class, but the motor ratings are the ones that govern sizing.
Termination and wiring
Main circuit terminals are screw-type, accepting solid conductors up to 2x 4 mm² (or 2x 0.5–1.5 mm²) and stranded up to 2x 25 mm². That covers most motor leads up to the size S2 frame. The coil connections share the same terminal block. Operating temperature range is -25 to +60 °C, storage -55 to +80 °C, so it handles typical panel environments without issue. Pollution degree 3 means it's rated for industrial atmospheres with conductive dust or condensation.