Abstract: AN EMPLOYEE WAS REMOVING TWO SCREWS FROM A BUSBAR IN A 3-PHASE, 208-VOLT, 1200-AMP MAIN DISCONNECT BREAKER BOX USING A 3/8-INCH RATCHET AND SOCKET THAT WERE NOT INSULATED. HE DID NOT TURN OFF THE POWER TO THE BOX. THE RATCHET CAME IN CONTACT WITH THE LIVE BUSBAR, AND HE RECEIVED AN ELECTRIC SHOCK. (THE BOX WAS MANUFACTURED BY FEDERAL PACIFIC.) THE BOLTS HE WAS REMOVING WERE 59 INCHES ABOVE THE FLOOR. THE MAIN SWITCH TO DISCONNECT POWER TO THIS BREAKER PANEL WAS LOCATED 36 INCHES AWAY. THE WRENCH CAUSED AN ARC BETWEEN THE "A" PHASE AND THE "B" PHASE. A SECOND EMPLOYEE WAS NEAR THE PANEL BOX. ALTHOUGH HE WAS NOT INVOLVED IN THE WORK, HE WAS ALSO INJURED. BOTH EMPLOYEES WERE HOSPITALIZED.