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The purpose of the Transformer Differential Protection Lab senior design project is to implement the transformer differential protection scheme to protect a transformer when an internal fault is applied. Using the Lab-Volt power supply, a Lab-Volt faultable transformer, and a SEL-787 relay; the transformer differential protection scheme was produced in the Power Lab found in Main Hall 303. During the project, the SEL-787 was tested for different scenarios that differential protection could be susceptible to. The scenarios tested were a primary winding-to-ground fault, an external fault, and harmonics that the transformer may experience during inrush. The outcomes of the project are to learn about transformer differential protection and produce a lab procedure that could be used as a future lab for Montana Tech’s Power Protection class.