The Siemens SIRIUS 3RT5944-5BB41 is a 24 V DC magnet coil designed for use with 230 V AC contactors in the SIRIUS contactor range. It uses a screw-type terminal connection, consistent with the standard wiring practice for panel builds where the coil is fed from a 24 V DC control supply.
This coil is a direct replacement for the coil on a SIRIUS contactor of the size that accepts the 3RT59 series accessory coils. The 24 V DC rating means it pulls in reliably at nominal bus voltage and holds in at the typical dropout threshold for the contactor frame. Screw terminals accept the same 0.5–2.5 mm² stranded wire as the contactor's control circuit.