An example terminal block may include a frame that is to attach to a power supply casing. The frame may be formed from an electrical insulator, and may include a base, exterior walls connected to the base, and a number of interior walls that separate an interior region of the frame into multiple compartments. The example terminal block may include a cover that may be formed from an electrical insulator and may be connected to the frame such that the cover may transition between an open position and a closed position. Each of the compartments may electrically isolate bus bars from one another, where the bus bars extend from within the power supply casing into the frame. The base may include a nut holder in each of the compartments, each of the nut holders having a cavity formed therein that is shaped so as to hold a nut captive.