The Siemens SIRIUS 3RT2037-3XJ40-0LA2 is a Size S2 contactor with an extended operating range coil and spring-type terminals on the magnet coil. It carries 65 A at 480 V and 52 A at 600 V, making it suitable for switching motor loads in control panels where those voltage and current ratings are required.
Mounting and panel fit
Mounts via screw or snap-on onto 35 mm standard mounting rail per DIN EN 60715. Dimensions are 114 mm high, 55 mm wide, 130 mm deep — the 55 mm width is the critical panel-spacing dimension for DIN-rail fill factor. Mounting position allows +/-180° rotation on a vertical surface, plus +/-22.5° tilt forward/backward, so it fits into tight enclosures without forcing a specific orientation.
Ratings and what they mean for fit
The headline 65 A at 480 V and 52 A at 600 V are the AC-1 resistive load ratings — the current the main contacts can carry continuously. For motor switching (AC-3 duty), the actual motor current must be lower; these numbers tell you the contactor can handle the inrush and break the stalled-rotor current of a motor sized within its thermal capacity. The extended operating range coil holds in over a wider voltage band than standard coils, which helps on lines with brownout or sag.
Coil and auxiliary details
The magnet coil uses spring-type terminals — no screw tightening, which speeds wiring in high-volume panel builds. Includes an auxiliary switch for status feedback or interlocking. DC coil dropout timing is 30 to 55 ms; arcing time is 10 to 20 ms, which matters for coordination with upstream protection.