What it is and what it does
The Siemens 3RT2038-1AC24 is a SIRIUS power contactor, size S2, designed for switching motor loads in control panels. Its headline rating is 65 A in AC-3 duty at 480 V, meaning it handles the inrush and breaking of three-phase induction motors up to that current. The coil is 24 V at 50 Hz. Mounting is via screw or snap-on onto a 35 mm DIN rail per DIN EN 60715, which is the standard for panel integration. The contactor measures 55 mm wide, 114 mm high, and 174 mm deep, so it occupies a single 55 mm slot on the rail.
Key ratings and what they mean for fit
The AC-3 rating of 65 A at 480 V is the one that governs motor switching — this contactor can start and stop a 480 V three-phase motor drawing up to 65 A full-load current. For resistive loads (AC-1), the maximum operating rate is 700 switching cycles per hour, while for AC-3 motor duty it is 500 cycles per hour. The AC-4 maximum (plugging/inching) is 150 cycles per hour. Operating temperature range is -25 to +60 °C, with storage from -55 to +80 °C. The mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, giving flexibility in tight enclosures. Main contact configuration is 3-pole (3 NO), and the auxiliary switch block is not included — it must be ordered separately if needed. The coil draw at 24 V rated value is 6 A.