EMPLOYEE WAS SHOCKED BY AN ELECTRICAL CURRENT OF 277V OF A CONFICURATION OF A 480 VOLT TEMPORARY SERVICE LINE. EMPLOYEE AND THREE OTHER CDK PERSONNEL WERE ATTEMTPING TO UNPLUG A CULVERT WITH A +72' RE-BAR SNAKE TOOL, WHEN THEY UNEXPECTEDLY AND UNKNOWINGLY STRUCK ONE LEG OF THE 480 VOLT LINE THAT CROSSED THEH CULVERT.