Control voltage and connection detail
The 3RT5945-5AG21: The control supply type is AC — confirm your control transformer output matches before wiring. Termination is screw-clamp, which suits retrofit work where existing ring or fork terminals are already crimped.
This is a magnet coil designed for Siemens SIRIUS contactors in the 3RT5 frame range. It replaces the coil on the contactor without removing the main power wiring — unclip the old coil, slide in the new one, and torque the screw terminals. The screw connection matches standard panel wiring practices; no special crimp tool needed.