The LiftMaster 25-4002-5D is an OEM adjustable thermal overload rated for 1.6–2.5 amps, designed to protect the drive motor in select LiftMaster commercial door operators. Installed as part of the motor starter assembly, this overload relay monitors current draw and trips when conditions exceed the set amperage, helping prevent motor overheating and damage. It serves as a direct replacement part for systems that specify 25-4002-5D in the service manual or parts list, making it a dependable solution for maintenance and repair of industrial and commercial overhead door openers.
For proper use, the trip dial should be set to match the motor’s full-load amperage as indicated on the motor data label. The device integrates with the existing contactor/starter block used in LiftMaster commercial operators and functions as a protective element within that control circuit. Installation and adjustment should be performed by a qualified technician with power locked out, following the operator’s documentation to confirm compatibility and correct settings. Common search terms include LiftMaster thermal overload relay, motor starter overload 1.6–2.5A, and commercial door operator replacement part.