Abstract: Two maintenance workers at an automobile manufacturing plant were troubleshooting a 480-volt electrical cabinet in the passenger paint department. The maintenance workers bypassed the circuit's overload protection without noticing that a motor they had installed was wired in reverse. The motor burned up and overloaded the circuit. Because the overload protection was inoperative, the overload caused an electrical fault in the cabinet. The ensuing electric arc caused the employee in front of the cabinet to fall backwards. (He might also have received an electric shock.) The employee injured his shoulder and strained his neck. He was hospitalized overnight for observation and returned to work the next week.