What the ratings mean for fit
The Siemens SIRIUS 3RT2038-3AF04 is a power contactor in the S2 frame size, rated 65 A at 480 V — that's the AC-3 motor-switching current, so it handles induction motor loads up to that level without derating. The 178 mm depth and 55 mm width fit a standard 35 mm DIN rail per DIN EN 60715, with screw and snap-on mounting. Spring-type terminals on the magnet coil speed up wiring — no screwdriver needed for the coil connections. Switching frequency varies by duty: 700 cycles/hour at AC-1 (resistive loads), 500 at AC-3 (motor start/run), and 150 at AC-4 (plugging/inching). For high-inertia loads or frequent reversing, the AC-4 limit governs — plan around 150 ops/hour max. Operating temperature spans -25 to +60 °C; storage range is -55 to +80 °C. Mounting position is flexible — ±180° rotation on a vertical surface, plus ±22.5° tilt forward/backward — useful when the panel layout forces an odd angle.
Panel integration
Mounts on 35 mm DIN rail per DIN EN 60715 — screw and snap-on, no adapter plate needed. The S2 frame is a common Siemens size; if your panel was laid out for a smaller S0 contactor like the 3RT2015 series, check the 55 mm width and 178 mm depth against your existing DIN rail spacing and gland-plate clearance. The 10 mm clearance upwards and forwards and 6 mm at the sides are minimums for arc flash and heat dissipation.