What it is and what it does
The Siemens 3RT2036-1CP04 is a SIRIUS power contactor, Size S2, designed for switching motor loads and resistive loads in industrial control panels. It carries a 52 A rating at 480 V in AC-3 duty, which is the standard category for starting and stopping squirrel-cage motors during running — that's the number that matters for sizing it against a motor nameplate. The contactor mounts on a 35 mm DIN rail per DIN EN 60715, either snapped on or screwed down, and its 55 mm width means it takes up one standard modular slot in a panel layout.
Ratings and what they mean for fit
The AC-3 rating of 52 A at 480 V tells you this contactor can handle a motor drawing that current in normal start/run duty — the kind of work a conveyor or pump motor sees every shift. For resistive loads (AC-1), the maximum switching rate is 1,000 operations per hour; for the heavy inching or plugging duty of AC-4, that drops to 250 per hour. The coil is rated at 50 Hz, 230 V, and draws 6 A at 24 V, 2 A at 48 V, tapering to 0.6 A at 440 V. The operating temperature range is -25 to +60 °C, with storage from -55 to +80 °C — wide enough for most panel environments, but if you're mounting this near a hot process line, keep the ambient under 60 °C.
Mounting and integration
Mounts on 35 mm DIN rail per DIN EN 60715, screw or snap-on. The mounting position allows +/-180° rotation on a vertical surface and can be tilted forward/backward by +/-22.5°. Clearance: 10 mm upward, 10 mm forward, 10 mm downward, 6 mm at the sides. The screw-type terminals accept 2x (0.5 to 1.5 mm²) solid or stranded, or 2x (0.75 to 2.5 mm²). Main contacts have a mechanical life of 18 million operations typical, and the coil terminals are screw-type. No auxiliary switch is built in — you'll need to add one separately if your circuit calls for feedback.