The Siemens 3RT1045-1AL20-ZW98 is a SIRIUS power contactor in size S3, designed for switching motor loads in industrial control panels. It mounts via screw or snap-on onto 35 mm or 75 mm standard DIN rails, so it integrates into existing panel layouts without adapter plates. The main current circuit uses screw-type terminals, rated for solid conductors up to 2x 4 mm² and stranded up to 2x 50 mm² — a range that covers most motor branch feeds up to the contactor's rated power. Per the datasheet, the operating temperature span is -25 to +60 °C, with storage down to -55 °C; pollution degree 3 means it tolerates conductive dust in typical factory environments.
Dimensions and Mounting
Footprint is 70 mm wide by 146 mm tall by 139 mm deep. Side-by-side mounting is permitted, so multiple contactors can be ganged on the same rail without mandatory spacing gaps — useful when packing a motor control center. The IP20 rating on the front with the cover or box terminal installed means the live parts are finger-safe inside the enclosure; the terminal itself is IP00, so the panel door must be closed before energizing.