Magnet coil for SIRIUS contactor – what it is
The 3RT5945-5AM01 is a replacement or spare magnet coil for Siemens SIRIUS contactors, designed to pull in and hold the contactor armature. It operates on 220 V AC supply, 50/60 Hz, drawing between 0.8 and 1.1 A at 50 Hz during the pick-up and hold cycle.
Current draw and what it means for the panel
The 0.8 to 1.1 A at 50 Hz is the coil's inrush and sealed current – the higher end is the pick-up surge, the lower end is the holding current once the contactor is closed. This determines the control transformer sizing and the fuse or circuit breaker protecting the control circuit. On a packed DIN-rail panel, that 1.1 A inrush can drop the control bus voltage if the transformer is undersized, so match the coil draw to the transformer VA rating.