What it is and where it fits
The Siemens 3RT2036-1AB00 is a SIRIUS power contactor in the S2 frame, designed for switching motor loads and resistive circuits in industrial control panels. It mounts on 35 mm DIN rail per DIN EN 60715, with screw and snap-on fastening, and accepts screw-type terminals for the coil and main contacts. The contactor is rated 52 A at 480 V AC-3, which covers the majority of 30–40 hp motor applications at that voltage. The AC-3 duty rating is the one that matters for motor starting — it governs the contactor's ability to break locked-rotor current without welding.
Switching frequency and mechanical life
Maximum switching rate varies by duty: 1,000 cycles per hour at AC-1 (resistive), 800 at AC-3 (motor start/run), 600 at AC-2 (slip-ring motor), and 250 at AC-4 (plugging/inching). Mechanical life is rated at 10 million operations typical — that's the bearing and armature wear limit, not the contact erosion curve. Arcing time spans 10 to 20 ms, and the contactor's opening time at AC is 10 to 18 ms. Those numbers matter for coordination with upstream short-circuit protection — the breaker or fuse needs to clear before the contactor welds on a fault.
Mounting and clearances
The S2 footprint is 55 mm wide, 114 mm tall, and 130 mm deep. Minimum clearances to adjacent components: 10 mm upward, 10 mm downward, 10 mm forward, and 6 mm to the side. Mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward. Wire range for main contacts accepts two conductors per clamp: 0.5 to 1.5 mm² or 0.75 to 2.5 mm² solid or stranded. That covers standard panel wiring up to 12 AWG.