What it is and what it does
The Siemens SIRIUS 3RT2036-3AL20-ZX95 is a size S2 power contactor, used to switch motor loads in control panels. Its headline rating is 52 A at 480 V in AC-3 duty (cites:) — that's the motor-switching current it handles for a typical three-phase induction motor, covering pumps, conveyors, and compressors up to that load. It mounts via screw and snap-on onto a 35 mm DIN rail per DIN EN 60715 (cites:), so it drops into a standard panel enclosure without extra brackets. The mounting position is flexible: ±180° rotation on a vertical surface, and can be tilted forward/backward by ±22.5° (cites:) — useful when you're fitting it into a tight gland-plate layout. The contactor includes an auxiliary switch (cites:), so you don't need to add a separate aux block for status feedback or interlocking. Coil terminals are spring-type (cites:), accepting 2x (0.5 to 2.5 mm²) solid or stranded wire (cites:) — quick to land with no screwdriver.
Sourcing and lifecycle reality
Operating temperature range is -25 to +60 °C (cites:), so it's fine for most indoor panel environments. Storage range is -55 to +80 °C (cites:) — that's the shipping and spares shelf limit, not the running condition.
Panel fit and integration
Dimensions: 114 mm high, 55 mm wide, 130 mm deep (cites:,). That 55 mm width is a single 3-module footprint on a DIN rail — plan your gland-plate fill factor accordingly. Spacing clearances: 10 mm upwards, 10 mm forwards, 10 mm downwards, 6 mm at the side (cites:,) — no extra air gap needed beyond those for heat dissipation. Mechanical life is 10 million operations typical (cites:). Electrical life depends on load: at AC-3 (motor switching) it's rated 800 cycles per hour maximum (cites:), at AC-4 (inching/jogging) 250 cycles per hour (cites:). If your application cycles faster than that, you'll need to oversize the contactor.