Abstract: EMPLOYEES OF AN ELECTRICAL CONTRACTOR WERE PERFORMING WORK AS PART OF A CONTRACT TO REPLACE A BURNED-OUT SWITCHGEAR IN A SUBSTATION ON THE ROOF OF AN AUTOMOTIVE MANUFACTURING PLANT. THE SWITCH HAD BEEN REPLACED ON FRIDAY, AND TWO WORKERS RETURNED ON SUNDAY MORNING TO HOOK UP THE FEEDERS (13.2 KILOVOLT, 3 PHASE) TO THE BACK OF THE SWITCH PANEL. THEY CHECKED THE TWO SWITCH PANELS WITH AN INSTRUMENT (TIF #300HV TIC-TRACER) AND GOT A CURRENT READING. THE TWO WORKERS WENT WITH PLANT MAINTENANCE PERSONNEL TO THE MAIN SUBSTATION, AND THE MAINTENANCE CREW RACKED OPEN TWO BREAKERS. EMPLOYEES #1 AND #2 VISIBLY CHECKED THIS, THEN PLACED THEIR LOCKS ON THEM AND RETURNED TO THE FIRST SUBSTATION. THEY RECHECKED THE LINES WITH THE TIC-TRACER AND GOT NO READING. THEY PROCEEDED TO UNWRAP THE TAPE FROM THE THREE PHASES IN THE BACK OF THE PANEL. THE BARED CONDUCTORS ARCED, BURNING AND SHOCKING BOTH WORKERS. THE FEEDERS WERE ENERGIZED BY VOLTAGE BACKFEED FROM ANOTHER FEEDER, UNTIL ITS BREAKER OPENED BECAUSE OF THE FAULT CURRENT.