The Siemens SIRIUS 3RT2036-3AN20 is a size S2 power contactor rated for 52 A in AC-3 duty at 480 V — that's the motor-switching current, meaning it handles a 3-phase induction motor load up to that amp draw without welding the main contacts on break. The AC-3 rating governs the real-world switching life: 800 operations per hour maximum, which aligns with conveyor and pump cycling in a production line. Coil termination uses spring-type terminals (cage clamp style), accepting 2x (0.5 to 2.5 mm²) solid or stranded wire. The auxiliary switch block is present on this variant — useful for feedback to a PLC or to seal in the holding circuit.
The S2 frame footprint is 55 mm wide, 114 mm tall, 130 mm deep. Clearance requirements: 10 mm above, 10 mm below, 10 mm forward, 6 mm sideways — tight enough for a crowded panel if you keep the arc-chamber venting clear. That covers most enclosure layouts without derating.