What it is and where it lands
The Siemens SIRIUS 3RT2016-1UB41 is a Size S00 power contactor — the smallest frame in the SIRIUS line, built for switching motor loads and resistive circuits inside a control panel. It snaps onto 35 mm DIN rail per DIN EN 60715, or screws down if you prefer a fixed mount. The 24 VDC coil pulls in at 0.8 of rated voltage and holds there; dropout happens below the release threshold, which keeps the contactor from chattering on a sagging bus. At 45 mm wide, 58 mm tall, and 73 mm deep, it fits into tight gland-plate layouts where every millimeter of DIN rail counts. The S00 frame leaves room for auxiliary contact blocks on the side without stealing the next slot over.
What the ratings mean for the buyer
The coil is rated at 24 VDC, and the main contacts carry 10 A at 24 VDC resistive (AC-1) and 3 A at 400 VAC. That AC-1 number — 10 A — is the resistive load curve; if you're switching motor loads under AC-3 duty, the contactor handles up to its rated operational current for that category, which for this frame size typically lands below the resistive figure. The switching frequency tops out at 1,000 operations per hour for AC-1, 750 per hour for AC-3, and 250 per hour for AC-4 (plugging/reversing). Those limits aren't theoretical — exceed them on a frequent-start conveyor and you'll cook the arc chamber. Operating temperature spans -25 to +60 °C, storage from -55 to +80 °C. Out here in the grease, that means the contactor survives a hot panel next to a motor starter or a cold warehouse over the weekend. The 10 mm clearance above and below, plus 6 mm to the side, is the minimum for arc flash and heat dissipation — don't cram it flush against the enclosure wall.
Panel integration and wiring
Screw-type terminals on the coil and main contacts accept solid or stranded wire from 0.5 to 4 mm², or two conductors in parallel (2x 0.5...1.5 mm², 2x 0.75...2.5 mm², or 2x 4 mm²). The mounting position allows ±180° rotation on a vertical surface, and forward/backward tilt up to ±22.5° — handy when you're wiring into a cramped enclosure and the gland plate forces an odd angle. Just keep the arc chamber clearances I mentioned above.