Abstract: A REFRIGERATION AND MAINTENANCE MECHANIC FOR AREA STORES WAS CALLED TO CHECK ON AN ELECTRICAL PROBLEM. THE EMPLOYEE FOUND THAT ONE OF THE PHASES OF THE THREE-PHASE SYSTEM WAS INOPERATIVE, CAUSING THE REFRIGERATION COMPRESSORS TO SHUT DOWN. SINCE THE OTHER TWO PHASES WERE STILL ENERGIZED, THE COMPRESSORS WERE TRYING TO RESTART, RESULTING IN A LARGE AMOUNT OF HEAT BUILD-UP WITHIN THE EQUIPMENT. THE EMPLOYEE TURNED OFF ALL THE BREAKERS AND HAD THE ELECTRIC UTILITY COMPANY COME OUT TO REPAIR THE INOPERATIVE PHASE. ONCE THE PHASE WAS REPAIRED, THE EMPLOYEE TURNED ON ALL THE CIRCUIT BREAKERS TO RESTORE POWER TO THE COMPRESSORS. ALL THE BREAKERS BUT ONE COULD BE RESET. THE EMPLOYEE OBTAINED A REPLACEMENT BREAKER AND ATTEMPTED TO INSTALL IT, BUT IT WOULD NOT FIT INTO THE PANEL. THE EMPLOYEE DECIDED TO OBTAIN A NEW BREAKER THE NEXT DAY AND TRY TO INSTALL IT. THE NEXT DAY, A NEW 70-AMPERE, 3-PHASE BREAKER WAS OBTAINED. THIS BREAKER ALSO WOULD NOT FIT INTO THE PANEL EVEN THOUGH IT WAS THE PROPER BREAKER. THE EMPLOYEE ATTEMPTED TO REALIGN THE BUSBAR WITH A PIECE OF INSULATED MATERIAL. THE BUSBAR SHORTED TO GROUND, CAUSING A FLASH AND FIRE. THE EMPLOYEE RECEIVED BURNS ON HIS HANDS. THE PANELBOARD WAS A 240-VOLT, 3-PHASE UNIT. THE EMPLOYEE HAD RECEIVED TRADE SCHOOL TRAINING AND ATTENDED PERIODIC SEMINARS. HE NORMALLY WORKED ALONE.