SIRIUS S3 Power Contactor – 3RT1044-3AK60
The Siemens 3RT1044-3AK60 is a SIRIUS S3 power contactor rated for motor switching at 37 kW at 500 V and 18.6 kW at 690 V, with screw-type terminals on the main circuit and an IP20 front enclosure. It mounts on 35 mm or 75 mm DIN rail via screw and snap-on fastening, sized for panel builders who need a rugged, serviceable contactor in a standard S3 frame.
Dimensions are 146 mm height, 70 mm width, and 139 mm depth — a compact S3 footprint that fits standard enclosures. Side-by-side mounting is allowed without derating for most load profiles.
This contactor handles AC-1 resistive loads at 1,000 operations per hour, AC-3 motor switching at 1,000 ops/h, and AC-4 inching/jogging at 300 ops/h. The AC-3 rating is the one that matters for most conveyor, pump, and fan applications — at 500 V it delivers 37 kW, at 690 V it delivers 18.6 kW. Coil draw at 24 V is 10 A, at 60 V is 2 A — low enough for most PLC outputs but verify your drive card's peak current.
Main circuit terminals accept solid conductors 2x (0.25–2.5 mm²) and stranded 2x (10–50 mm²) — covers everything from control wiring to motor feeders. The screw-type terminal block is field-serviceable; no special tools beyond a screwdriver. For the auxiliary contacts (if fitted), the same solid range applies. Strip length and torque values are standard for the SIRIUS family — no surprises for a panel builder familiar with the range.