What was found
DURING A MAINTENANCE EVENT ON THE AIRCRAFT, NOTED THAT THE INVERTER AUTO CHANGEOVER SYSTEM WAS INOPERATIVE WHEN THE NR 1 INVERTER WAS SELECTED OFF. THE MAINTENANCE TEAM INVESTIGATED AND FOUND THE B2 CIRCUIT BREAKER ON THE LT XZ ELECTRICAL PANEL WAS TRIPPED. FURTHER INVESTIGATION THAT THE HYDROSTATIC TESTING METAL TAG FOR THE NR 2 ENGINE FIRE BOTTLE WAS CONTACTING ELECTRICAL TERMINALS ON AN ADJACENT RELAY CAUSING THE B2 CIRCUIT BEAKER TO TRIP. THE DATA TAG WAS POSITIONED TO BE CLEAR OF ELECTRICAL EQUIPMENT. THE AIRCRAFT WAS RETURNED TO SERVICE.