SIRIUS S3 contactor with 110 VDC coil
The Siemens 3RT2046-1XF40-0LA2 is a SIRIUS-branded Size S3 contactor designed for switching motor loads in industrial control panels. Its 110 VDC coil with screw-type terminals is a specific variant for DC control circuits, common in applications where a separate DC supply or battery-backed control bus is used. Rated for 96 A at 480 V and 77 A at 600 V in AC-3 duty, this frame handles motors up to roughly 50–75 hp depending on the line voltage — a solid fit for medium-horsepower pumps, fans, and compressors in a 480 V plant. The 70 mm width and 152 mm depth place it in the standard S3 footprint, and it mounts via screw or snap-on to 35 mm DIN rail per DIN EN 60715, so it drops into existing panel layouts without re-drilling.
Coil and control circuit specifics
The DC coil on this contactor is rated 110 V nominal, with an inrush current peak of 1.5 A and a pickup/dropout timing of 38 to 57 ms. The arcing time across the main contacts runs 10 to 20 ms. For a controls integrator, the DC coil means no AC hum and a clean pickup, but the control transformer or power supply must be sized for the 1.5 A inrush peak — not just the sealed holding current. The contactor includes an auxiliary switch (1 N.O. + 1 N.C. typical for this frame), which is useful for status feedback to a PLC or for electrical interlocking in a reversing starter pair. Wire capacity on the coil and aux terminals accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded — standard for panel wiring with ferrule or direct termination.
Mounting and environmental tolerances
Mounting position is flexible: the contactor allows +/-180° rotation on a vertical surface and can be tilted forward/backward by +/-22.5° on a vertical surface. This helps when fitting into tight enclosures or odd-angle subpanels. Required clearances around the contactor are 10 mm upwards, 20 mm forwards, 10 mm downwards, and 10 mm at the sides — important to note when laying out a dense DIN-rail assembly to avoid derating from heat buildup. Operating temperature range is -40 to +70 °C, with storage from -55 to +80 °C. That covers most indoor industrial environments and unheated warehouses.