Abstract: AN ELECTRICIAN AT A CITY WATER TREATMENT PLANT WAS TROUBLESHOOTING AN ELECTRICAL FAULT IN A LOW-VOLTAGE AC CONTROL CIRCUIT. THE CONTROL CIRCUITS WERE IN THE SAME ENCLOSURE AS A 2500-VOLT, THREE-PHASE CIRCUIT USED TO SUPPLY BOOSTER PUMPS. THE CABINET HOUSING THE CIRCUITS WAS AN SAF 400 UNIT WITH A 50-KILOVOLT INTERRUPTER WITH A VQ CONTACTOR (SERIAL NO. 5-76-1807-21) TO SWITCH THE HIGH VOLTAGE CIRCUIT. THE EMPLOYEE BY-PASSED THE INTERLOCK, SO THE CONTACTOR REMAINED ENERGIZED AT 5000 VOLTS. HE WAS USING A MULTIMETER TO CHECK THE LOW-VOLTAGE CIRCUIT WHEN HE INADVERTENTLY CONTACTED PARTS OF THE HIGH-VOLTAGE CIRCUIT WITH THE METER'S TEST LEADS. THE EMPLOYEE, WHO WAS NOT USING ELECTRICAL PROTECTIVE EQUIPMENT, WAS BURNED ON HIS FACE, CHEST, AND ARMS. HE WAS TRANSPORTED TO A BURN CENTER, WHERE HE WAS HOSPITALIZED FOR HIS INJURIES.