What was found
PHL - FLT 1798 - ALL NORMAL POWER FAILED WHILE EN ROUTE FROM IAH TO PHL, WHEN THE NR 1 NORMAL TRANSFER BUS CIRCUIT BREAKER TRIPPED APPROXIMATELY 300 MILES FROM PHL. THE AIRCRAFT WAS ON BATTERY POWER ONLY. THE AIRCRAFT LANDED AT PHL WITHOUT INCIDENT. MAINTENANCE OPERATED THE BUS TRANSFER SYSTEM OFF APU AND NR 1 ENGINE GENERATOR POWER. THE FAILURE COULD NOT BE DUPLICATED. THE NR 1 NORMAL TRANSFER BUS CIRCUIT BREAKER WAS REPLACED AS A PRECAUTIONARY MEASURE. OPERATION CHECKED GOOD ON THE GROUND. (X)