The LiftMaster K03-8224-D Contactor is an OEM replacement component for LiftMaster D-Line commercial operator systems. It uses a 24-volt control coil to energize and switch motor power within the operator, restoring reliable open/close operation when a worn or failed contactor is the cause of erratic movement, motor hesitation, or failure to start. Designed specifically for D-Line control assemblies, this contactor integrates into the existing control circuit to manage line voltage to the drive motor in professional-grade LiftMaster door and gate applications.
As a direct-fit replacement part, the K03-8224-D maintains original equipment performance and wiring layout. The 24-volt coil matches the D-Line control voltage, and the unit is typically installed inside the operator’s control enclosure following the model’s wiring diagram. For safety and compliance, installation should be performed by a qualified technician with power locked out; verify terminal labeling, replicate lead placement from the original part, and function-test all controls and safety devices after replacement. Compatibility can vary by operator model within the D-Line family, so consult your specific operator’s parts list or service manual to confirm fit. This genuine LiftMaster contactor is suited for commercial and industrial environments where dependable motor control, serviceability, and long-term support are essential.