What the 52 A at 480 V rating means for your motor circuit
The Siemens 3RT2036-1AH04 is a SIRIUS Size S2 power contactor rated 52 A at 480 V — that is the AC-3 motor-switching current, meaning it handles a 3-phase induction motor drawing up to 52 A during starting and running, without welding the main contacts on inrush. For a 480 V supply, that translates to roughly a 30–40 hp motor, depending on the exact full-load current curve. The contactor snaps onto a 35 mm DIN rail per DIN EN 60715 and measures 55 mm wide by 114 mm high by 174 mm deep — the 174 mm depth is the dimension that matters most when planning gland-plate clearance or a shallow enclosure back-panel.
Mounting and integration — DIN rail, screw terminals, position flexibility
The 6 mm side gap is tighter than the vertical ones — plan the DIN-rail spacing accordingly to avoid heat buildup between adjacent contactors. Main contact arrangement is 3-pole (18...1 designation), and the coil terminals are screw-type. Wire capacity accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded.
Maximum operating frequency varies by duty: 1,000 cycles/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). The AC-3e rating matches the AC-3 figure at 800 cycles/hour. If your application involves frequent jogging or reversing, the AC-4 limit of 250 cycles/hour is the governing spec — exceeding it accelerates contact wear. Arcing time is 10 to 20 ms, and the make/break time at AC is 10 to 18 ms. These are fast enough for most motor-control circuits but matter for coordination with upstream short-circuit protection — the arc clears before the breaker's instantaneous trip can see the fault current.