Abstract: AN ELECTRICAL WORKER WAS ASSIGNED TO CHECK A PROBLEM WITH A GROUND FAULT ON A SWITCHGEAR PANEL. THE PROBLEM HAD BEEN NOTED THE PREVIOUS DAY WHEN A RED LIGHT ON THE PANEL LIT. THE CIRCUIT BREAKERS HAVE RED TRIP BUTTONS TO OPERATE THE 600-VOLT, 800-AMPERE, 3-PHASE CIRCUIT BREAKERS. THE EMPLOYEE WAS PRESSING EACH OF THE EIGHT TRIP BUTTONS. WHEN HE GOT TO THE THIRD ONE, WHICH CONTROLLED POWER TO THE TOOL ROOM, HE HAD TO LIE ON THE FLOOR TO PUSH THE BUTTON, WHICH WAS AT THE BOTTOM OF THE PANEL. WHEN HE PRESSED THIS BUTTON, THE SWITCHGEAR EXPLODED, DUE TO A DEFECT IN THE CIRCUIT BREAKER. THE ELECTRICAL EXPLOSION AT THIS CIRCUIT BREAKER CASCADED TO THE OTHER BREAKERS IN THE PANEL. THE EMPLOYEE RECEIVED SEVERE BURNS ON HIS HANDS, FOR WHICH HE WAS HOSPITALIZED.