What the ratings mean for fit
The Siemens 3RT1046-1BP44 is a SIRIUS power contactor in the Size S3 frame, designed for switching motor loads and resistive circuits in industrial control panels. Its headline AC-4 rating of 80 A at 400 V tells you the contactor is built for the most severe duty — plugging and inching of squirrel-cage motors, where the contacts must break full locked-rotor current. For less demanding AC-2 duty (starting and running slip-ring motors), it carries 45 kW at 400 V. The screw-type main terminals accept stranded conductors up to 2x 50 mm², so it handles the cable sizes typical of 45–80 A motor branches without a terminal adapter. Mounting is flexible: the contactor snaps onto 35 mm or 75 mm DIN rail, or can be screw-fastened to a backplate. Side-by-side mounting is permitted, which saves panel width when ganging multiple contactors on a common bus. The IP20 enclosure on the front with the box terminal means the live parts are touch-safe in a standard IP54 cabinet; the terminal body itself is IP00, so the wiring compartment must be inside the enclosure.
Lifecycle and sourcing reality
The contactor carries a substance prohibition date of 05/01/2012, indicating RoHS compliance per the EU directive effective from that date. The operating temperature range of -25 to +60 °C and storage range of -55 to +80 °C suit most industrial environments, including unheated warehouses and outdoor cabinets with solar loading.
Integration and wiring
The screw-type terminals on the main circuit accept solid conductors from 2x (0.5 to 1.5 mm²) up to 2x (0.75 to 4 mm²) for control wiring, and stranded conductors from 2x (2.5 to 16 mm²) up to 2x (10 to 50 mm²) for power. The auxiliary contact block is wired separately through the front-facing terminals. Coil arcing time is 10 to 15 ms, and dropout delay at DC is 14 to 20 ms — useful when coordinating with a PLC scan cycle or safety relay timing. Dimensions are 146 mm height, 70 mm width, and 201 mm depth. The 70 mm width matches the standard Size S3 footprint, so it occupies the same DIN-rail space as other S3 contactors from the SIRIUS family. The 201 mm depth includes the arc chamber and terminal overhang — verify clearance to the cabinet door or busbar shroud, especially in shallow enclosures.