Narrative:

Aircraft was on a maintenance ferry from phl to tul. Approximately 2 hours 10 mins into the flight, the #1 generator faulted. At this time, aircraft was at FL350 and fuel was xferring forward from the trim tank to the center. The APU was running, having been started as a precaution at phl and remained running throughout the flight. When generator #1 faulted, the APU picked up the load on AC bus #1. The ECAM electrical page showed generator #1 with no volts/frequency and all electrical busses pwred. Approximately 10 mins after generator #1 failed, the APU dropped off the line failing the AC bus #1 and the AC ess bus. Generator #2 then failed to pick up AC bus #1. At this time, aircraft had a generator #1 fault and an AC ess bus fault. 'Ovrd supp #2' was selected on and it pwred the AC ess bus. The AC bus #1 remained unpwred. After landing, the gpcu panel in the east&east compartment showed a gcu fail, code back course and a dp trip. Callback conversation with reporter revealed the following information: the reporter stated the aircraft was an airbus 300 and was on a maintenance ferry. The reporter said the following units were replaced to correct the #1 bus failure problems: essential xformer rectifier unit, left center tank fuel boost pump, the #1 generator control panel and the #1 integrated drive unit was svced. The reporter stated the airplane then was rted to kin where the #1 bus again failed and the aircraft was maintenance ferried to ZZZ for correction. The reporter said maintenance found chaffed wiring which was sensed as a differential fault causing the #1 bus to trip and lockout the APU bus from pwring the #1 bus.

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Original NASA ASRS Text

Title: AN AIRBUS 300 IN CRUISE AT FL350 HAD THE #1 AC BUS FAIL AND COULD NOT PWR THE BUS WITH THE APU GENERATOR BUS.

Narrative: ACFT WAS ON A MAINT FERRY FROM PHL TO TUL. APPROX 2 HRS 10 MINS INTO THE FLT, THE #1 GENERATOR FAULTED. AT THIS TIME, ACFT WAS AT FL350 AND FUEL WAS XFERRING FORWARD FROM THE TRIM TANK TO THE CTR. THE APU WAS RUNNING, HAVING BEEN STARTED AS A PRECAUTION AT PHL AND REMAINED RUNNING THROUGHOUT THE FLT. WHEN GENERATOR #1 FAULTED, THE APU PICKED UP THE LOAD ON AC BUS #1. THE ECAM ELECTRICAL PAGE SHOWED GENERATOR #1 WITH NO VOLTS/FREQ AND ALL ELECTRICAL BUSSES PWRED. APPROX 10 MINS AFTER GENERATOR #1 FAILED, THE APU DROPPED OFF THE LINE FAILING THE AC BUS #1 AND THE AC ESS BUS. GENERATOR #2 THEN FAILED TO PICK UP AC BUS #1. AT THIS TIME, ACFT HAD A GENERATOR #1 FAULT AND AN AC ESS BUS FAULT. 'OVRD SUPP #2' WAS SELECTED ON AND IT PWRED THE AC ESS BUS. THE AC BUS #1 REMAINED UNPWRED. AFTER LNDG, THE GPCU PANEL IN THE E&E COMPARTMENT SHOWED A GCU FAIL, CODE BC AND A DP TRIP. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS AN AIRBUS 300 AND WAS ON A MAINT FERRY. THE RPTR SAID THE FOLLOWING UNITS WERE REPLACED TO CORRECT THE #1 BUS FAILURE PROBS: ESSENTIAL XFORMER RECTIFIER UNIT, L CTR TANK FUEL BOOST PUMP, THE #1 GENERATOR CTL PANEL AND THE #1 INTEGRATED DRIVE UNIT WAS SVCED. THE RPTR STATED THE AIRPLANE THEN WAS RTED TO KIN WHERE THE #1 BUS AGAIN FAILED AND THE ACFT WAS MAINT FERRIED TO ZZZ FOR CORRECTION. THE RPTR SAID MAINT FOUND CHAFFED WIRING WHICH WAS SENSED AS A DIFFERENTIAL FAULT CAUSING THE #1 BUS TO TRIP AND LOCKOUT THE APU BUS FROM PWRING THE #1 BUS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.