Abstract: AN EMPLOYEE WAS REPAIRING A RUNWAY/TAXIWAY LIGHTING SYSTEM. HE WAS ISOLATING CURRENT LEAKS THAT WERE CAUSING DIMMING OF SOME OF THE LIGHTS. TO PERFORM THIS JOB, THE EMPLOYEE LOCKED OUT THE 2400-VOLT LIGHTING SYSTEM AND DUG UP THE LIGHTS. THE SYSTEM WAS RUN AS A 2400-VOLT CIRCUIT LEADING TO UNDERGROUND TRANSFORMERS THAT REDUCED THE VOLTAGE TO 4.5 VOLTS FOR THE LIGHTING FIXTURES. THE EMPLOYEE DUG UP THE DIM LIGHTS DOWN TO THE TRANSFORMERS, CHECKED THE PLUG-IN UNITS, TAPED SOME OF THEM, AND THEN PLACED THEM ON BOARDS. HE REENERGIZED THE 2400-VOLT SYSTEM AND CHECKED OUT THE LIGHTS, MEASURING FOR 4.5 VOLTS AND 5 TO 6 AMPERES AT EACH LIGHT. WITHOUT DEENERGIZING THE SYSTEM AND LOCKING IT OUT, THE EMPLOYEE PLACED THE TRANSFORMERS AND FIXTURE MOUNTS INTO HOLES AND BURIED THEM. HE HAD REPLACED ALL THE LIGHTING STANDARDS AND LIGHTS EXCEPT FOR ONE THAT WAS DAMAGED. THE EMPLOYEE REPLACED THE BREAKAWAY PORTION OF THAT STANDARD AND WAS RECONNECTING THE PLUG TO THE 4.5-VOLT SECONDARY OF THE TRANSFORMER WHEN THE 2400-VOLT PRIMARY, WHICH WAS LEAKING TO GROUND, ARCED TO HIS GLOVES. THE RESULTANT ELECTRIC SHOCK KNOCKED HIM 10 FEET AWAY.