What this part is and where it fits
The Siemens SIRIUS 3RT1935-5AN21 is a magnet coil designed for Size S2 contactors in the SIRIUS family. It operates on a 220 V AC control supply at both 50 Hz and 60 Hz, drawing 0.8 to 1.1 A at 50 Hz. The screw terminal connection matches the standard wiring practice for SIRIUS contactor assemblies.
What the ratings mean for fit
The 220 V AC rating at both 50 Hz and 60 Hz means this coil is a straight swap for any SIRIUS Size S2 contactor originally specified with a 220 V AC coil. The 0.8 to 1.1 A holding current at 50 Hz is the steady-state draw after the contactor picks up; the inrush will be higher, but this is the figure for sizing the control transformer.
Panel integration note
This coil mounts directly onto the SIRIUS Size S2 contactor frame via screw terminals. No special tools beyond a standard screwdriver are needed. The contactor itself snaps onto a 35 mm DIN rail per EN 50022, so the coil replacement is a panel-side swap without removing the contactor from the rail.