The Siemens SIRIUS 3RT5945-5AQ01 is a replacement magnet coil for contactors in the SIRIUS platform, designed for AC control supply voltage at 380 V rated value at 50 Hz. The coil's operating tolerance band of 0.8... 1.1 at 50 Hz means it will reliably pick up and hold across a voltage range of roughly 304 V to 418 V — a margin that covers typical line sag without nuisance dropout.
Panel Integration
As a SIRIUS-series magnet coil, the 3RT5945-5AQ01 mounts directly onto the contactor armature — no separate DIN-rail footprint. The AC coil draws its control voltage from the contactor's coil terminals; verify the control transformer is sized for the inrush VA of the specific contactor frame this coil drives. The 0.8... 1.1 tolerance band at 50 Hz ensures reliable operation even on lightly loaded control transformers where voltage may sag during simultaneous pickup of multiple contactors.