Abstract: Two electricians were cleaning, inspecting, and otherwise maintaining the 480/277-volt electrical system for an eight-story office building. One of the two employees, a journeyman electrician, noticed an employee of the electric utility company driving away from an electrical vault at the rear of the building. He assumed that the electrical service was deenergized. He also checked an open switch that was marked as the "main disconnect" with an Ideal inductive voltage indicator. When he later used a 0.5-inch socket wrench on a lug on the line side of an elevator disconnect switch, the wrench touched the grounded metal cabinet and created an electrical fault. The ensuing electric arc burned the employee on his face and wrists. He was hospitalized for his injuries. The inductive tester was claimed to have been not working. However, it was not recovered.