Narrative:

At approximately FL220, #2 generator breaker tripped followed shortly by #3. Leveled at FL240, advised ZMA we wished to return to tpa. Flying duties given to first officer. Captain and so troubleshot problem. No system annunciation came on to indicate why the gbs tripped. Downloaded electrical system to 29 kilowatts. Book calls for 36 kilowatts maximum. Contacted msp dispatch and maintenance control to discuss problem. We reset both generator breakers. System became normal. Checked volts and frequencys of each generator. Isolated and in parallel. All indications normal, no associated system failure elsewhere. After flying several mins with the electrical system reset and operating normally dispatch asked if we would turn back toward our original destination of mbj, jamaica. We, along we maintenance control, agreed the system was operating normally. We were released present position to mbj by msp dispatch. ATC reclred the flight on its original flight plan. The flight operated totally normal through landing and taxi in at mbj. While on the ground there, captain approached the local man in charge and asked if there was a mechanic he could speak to. The captain was told 'there is not one.' since the aircraft was operating normally, the return leg to tpa, fl, was begun. Normal taxi, takeoff and area departure was made. During climb out near the 'putul intersection' south of cuba on UG430, #2 and #3 generator breakers tripped again. Still no annunciator indication, no associated system failure elsewhere. We downloaded to 29- 30 kilowatts, climbed at slightly reduced power setting on #2 and #3 engines, received clearance from havana radio to cruise at FL260, reset the circuit breakers and completed the trip normally. During the trip north, company was again contacted and told that aircraft would require maintenance upon arrival at tpa. Callback conversation with reporter revealed the following: reporter is unaware of any corrective action that was taken on the aircraft. He said that the generators all assumed equal loads when they were isolated. He has no idea of why the generators chronically trip. The FAA is unhappy with his actions.

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Original NASA ASRS Text

Title: LGT LOST 2 GENERATORS AND BEGAN TO RETURN TO MIA. WHEN BOTH GENERATORS WERE REGAINED, THE FLT CONTINUED TO MBJ.

Narrative: AT APPROX FL220, #2 GENERATOR BREAKER TRIPPED FOLLOWED SHORTLY BY #3. LEVELED AT FL240, ADVISED ZMA WE WISHED TO RETURN TO TPA. FLYING DUTIES GIVEN TO FO. CAPT AND SO TROUBLESHOT PROB. NO SYS ANNUNCIATION CAME ON TO INDICATE WHY THE GBS TRIPPED. DOWNLOADED ELECTRICAL SYS TO 29 KILOWATTS. BOOK CALLS FOR 36 KILOWATTS MAX. CONTACTED MSP DISPATCH AND MAINT CTL TO DISCUSS PROB. WE RESET BOTH GENERATOR BREAKERS. SYS BECAME NORMAL. CHKED VOLTS AND FREQS OF EACH GENERATOR. ISOLATED AND IN PARALLEL. ALL INDICATIONS NORMAL, NO ASSOCIATED SYS FAILURE ELSEWHERE. AFTER FLYING SEVERAL MINS WITH THE ELECTRICAL SYS RESET AND OPERATING NORMALLY DISPATCH ASKED IF WE WOULD TURN BACK TOWARD OUR ORIGINAL DEST OF MBJ, JAMAICA. WE, ALONG WE MAINT CTL, AGREED THE SYS WAS OPERATING NORMALLY. WE WERE RELEASED PRESENT POS TO MBJ BY MSP DISPATCH. ATC RECLRED THE FLT ON ITS ORIGINAL FLT PLAN. THE FLT OPERATED TOTALLY NORMAL THROUGH LNDG AND TAXI IN AT MBJ. WHILE ON THE GND THERE, CAPT APCHED THE LCL MAN IN CHARGE AND ASKED IF THERE WAS A MECH HE COULD SPEAK TO. THE CAPT WAS TOLD 'THERE IS NOT ONE.' SINCE THE ACFT WAS OPERATING NORMALLY, THE RETURN LEG TO TPA, FL, WAS BEGUN. NORMAL TAXI, TKOF AND AREA DEP WAS MADE. DURING CLBOUT NEAR THE 'PUTUL INTXN' S OF CUBA ON UG430, #2 AND #3 GENERATOR BREAKERS TRIPPED AGAIN. STILL NO ANNUNCIATOR INDICATION, NO ASSOCIATED SYS FAILURE ELSEWHERE. WE DOWNLOADED TO 29- 30 KILOWATTS, CLBED AT SLIGHTLY REDUCED PWR SETTING ON #2 AND #3 ENGS, RECEIVED CLRNC FROM HAVANA RADIO TO CRUISE AT FL260, RESET THE CIRCUIT BREAKERS AND COMPLETED THE TRIP NORMALLY. DURING THE TRIP N, COMPANY WAS AGAIN CONTACTED AND TOLD THAT ACFT WOULD REQUIRE MAINT UPON ARR AT TPA. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: RPTR IS UNAWARE OF ANY CORRECTIVE ACTION THAT WAS TAKEN ON THE ACFT. HE SAID THAT THE GENERATORS ALL ASSUMED EQUAL LOADS WHEN THEY WERE ISOLATED. HE HAS NO IDEA OF WHY THE GENERATORS CHRONICALLY TRIP. THE FAA IS UNHAPPY WITH HIS ACTIONS.

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.