The Siemens 3RT1924-5AF02 is a SIRIUS magnet coil designed for Size S0 contactors. It operates on 110 V AC control voltage at 50 Hz, with a rated operating range of 0.8 to 1.1 times the nominal voltage. The coil terminates via spring-cage terminals — a push-in style that saves wireman time versus screw clamps on the panel rail.
This part is flagged as a phased-out product. The official successor is the SIRIUS 3RT2 series, which uses a different coil platform and mounting interface.
The 0.8 to 1.1 voltage tolerance at 50 Hz means the coil will pick up and hold reliably when the control supply stays between 88 V and 121 V AC. Below 88 V the armature may chatter or fail to seal; above 121 V you risk overheating the winding. The 110 V AC, 50 Hz spec is fixed — this coil will not work on a 60 Hz supply or on DC control buses.