What it is and what it does
The Siemens 3RT1036-1AR60-1AA0 is a SIRIUS power contactor in size S2, designed for switching motor loads in industrial control panels. Its AC-3 rating of 30 kW at 500 V means it handles the high inrush of squirrel-cage motors during starting, while the AC-2 rating of 22 kW at 400 V covers slip-ring motor duty. The coil is wound for 400 V at 50 Hz or 400 to 440 V at 60 Hz, with an operating range of 0.8 to 1.1 times rated voltage at 50 Hz and 0.85 to 1.1 at 60 Hz, so it holds in during brownout conditions down to about 320 V. Mounting is screw and snap-on onto a 35 mm DIN rail per EN 50022, and side-by-side mounting is permitted, so you can pack multiple units in a row without derating for heat buildup. The front face carries an IP20 rating for finger-safe touch protection; the terminal area is IP00, meaning the wiring compartment is open and requires enclosure protection.
Ratings that matter for fit
The main power circuit uses screw-type terminals. Solid wire capacity is 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), max 2x (0.75 to 4 mm²); stranded accepts 2x (0.75 to 25 mm²). That 25 mm² stranded top-end is generous for an S2 frame — it lets you land a 4 AWG cable without pigtailing down. The auxiliary contacts are rated 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V, which covers typical PLC and relay interposing loads. Mechanical life is 10 million operations typical. Maximum switching frequency varies by duty: 1000 cycles/hour for AC-1 resistive loads, 800 for AC-3 motor starting, 400 for AC-2 slip-ring, and 300 for AC-4 plugging/inching. If your application cycles a conveyor motor at 600 starts per hour, the AC-3 limit of 800 gives headroom; for a crane hoist with inching duty, the AC-4 limit of 300 is the binding constraint.