The Siemens 3RT6924-5AR61 is a SIRIUS replacement magnet coil designed for size S0 motor contactors rated up to 7.5 kW. It is the energizing component that pulls in the contactor armature, so when a coil fails in the field, this is the service part that keeps the panel running without replacing the entire contactor. The coil is wound for AC control voltage: 400 V at 50 Hz and 440 V at 60 Hz, with a pickup/holding tolerance band of 0.8... 1.1 times the rated voltage at 50 Hz and 0.85... 1.1 at 60 Hz. That means the coil will reliably pull in and hold as long as the control supply stays within those voltage windows — useful to check if your line-side voltage sags under heavy load. The screw terminals match the existing wiring on S0 contactors — no crimp changes needed for a swap.
The 3RT6924-5AR61 is the AC coil variant for size S0 contactors. If your existing contactor uses a different coil voltage (e.g., 230 V or 24 V DC), this coil will not pull in — the control circuit must match the coil rating. The screw terminal interface is standard for S0, so mechanical fit is consistent across the frame size.
Mounts on the contactor armature within the S0 footprint. No additional DIN rail space is consumed — the coil is an integral part of the contactor assembly. Verify the control supply is AC and within the 0.8–1.1 tolerance band before energizing; a low-voltage condition at pickup can cause chattering or weld the main contacts.