The Siemens SIRIUS 3RT2036-3AG20 is a Size S2 power contactor rated for 52 A at 480 V in AC-3 duty, and 10 hp at 230 V for motor starting. It uses spring-type terminals on the magnet coil and main contacts, so no screwdriver torque check on the coil wiring — just strip, insert, and it's locked. The contactor snaps onto standard 35 mm DIN rail (DIN EN 60715) and can be mounted in any orientation within ±180° rotation on a vertical surface, plus ±22.5° tilt forward or backward.
Mounting and integration
Panel space is tight? The 3RT2036-3AG20 footprint is 55 mm wide, 114 mm tall, and 130 mm deep. Clearance requirements: 10 mm upwards, 10 mm forwards, 10 mm downwards, and only 6 mm to the side. That 6 mm side gap is unusually tight — you can pack contactors side-by-side without the usual 10 mm air gap, which helps when you're squeezing three of these into a 200 mm wide enclosure. Operating temperature range is -25 to +60 °C, with storage from -55 to +80 °C. That covers most non-condensing indoor panels and unheated warehouses.
Switching performance and auxiliary contacts
The contactor carries 18 auxiliary contacts, configurable as 1 NO + 1 NC by default (the "18...1" designation means 18 terminals, 1 auxiliary block). The auxiliary contacts are rated for 10 A at 24 V, 2 A at 48 V or 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, 3 A at 400 V, and 0.6 A at 440 V — so a 24 VDC PLC output can drive the coil directly, and the aux contacts can switch a 24 VDC pilot light without a relay interposer. Switching frequency depends on the duty cycle: up to 1000 operations per hour in AC-1 (resistive loads), 800/h in AC-3 (motor starting), 600/h in AC-2 (slip-ring motors), and 250/h in AC-4 (plugging/inching). That AC-3 figure of 800/h is typical for a conveyor line cycling every 4.5 seconds — fine for most material handling, but if you're running a press brake that cycles every 2 seconds, you'll need the AC-4 rating to hold up. Arcing time is 10 to 20 ms, and the make/break time on AC is 10 to 18 ms. That's fast enough for most motor control circuits; the arc extinguishes within one half-cycle at 50 Hz.
If you're comparing against the smaller-frame 3RT2016-1AG62 (Size S0, 40 A at 480 V), the 3RT2036-3AG20 (Size S2, 52 A at 480 V) is a frame size up. The S2 is physically larger — 55 mm wide vs 45 mm for S0 — so it won't drop into a panel drilled for the S0 footprint without a new DIN rail bracket or adapter plate. The terminal type also differs: the 3RT2036-3AG20 uses spring-type terminals, while the 3RT2016-1AG62 uses screw terminals. If your panel wiring is already terminated with ferrules, the spring clamp is faster; if it's ring-tongue terminals, you'll need to cut and re-ferrule.