Magnet coil for SIRIUS S3 contactors — 110 V DC, spring-loaded termination
The Siemens SIRIUS 3RT1944-5BF42 is a DC magnet coil rated at 110 V, designed for Size S3 contactors in the SIRIUS family. It uses spring-loaded connection technology, which means the coil wires terminate into cage-clamp terminals — no screwdriver torque required, faster panel wiring, and vibration-resistant retention on the DIN rail.
Lifecycle and replacement path
This coil is marked as a phased-out product. The official successor is the SIRIUS 3RT2 series coil.