The Siemens SIRIUS 3RT6924-5AC21 is a magnet coil designed for motor contactors rated up to 7.5 kW in size S0, with screw terminals for the control circuit connection. This is the replacement coil for the contactor's electromagnet — when the coil fails, the contactor won't pull in, and this is the service part you swap in on the bench or in the panel.
Fit & Integration
Mounts into S0-frame Siemens SIRIUS contactors that accept a separate magnet coil — typically the 3RT2 series contactors in the 7.5 kW class at 400 V AC-3. Screw terminals match the existing control wiring; no crimp or special tool needed for the coil connections.