B757 captain reported that while he was out of the flight deck; the aircraft had electrical anomalie...

Narrative:

During cruise at FL380 with the captain in lavatory and first officer at his station and one flight attendant in cockpit jump seat for two person rule. Auto pilot tripped off and numerous lights and master warning (auto pilot kicked off) associated with the following lights on the overhead panel: left gen cont 'off' light; left bus 'bus off' light; and bus tie 'isln' light. Captain returned from lavatory and worked with first officer; who started the APU to try to restore lost systems including transponder which ATC notified was not sending. We went through the checklist for left gen cont. Systems were restored. While talking to maintenance control and dispatch we reviewed the checklist and agreed that the one reset was allowed per the checklist; and with all systems restored we continued to destination without further issues.

Original NASA ASRS Text

Title: B757 Captain reported that while he was out of the flight deck; the aircraft had electrical anomalies. The left generator shuts down and the left bus becomes unpowered. After returning to the cockpit the generator is successfully reset using the checklist.

Narrative: During cruise at FL380 with the Captain in lavatory and First Officer at his station and one Flight Attendant in cockpit jump seat for two person rule. Auto pilot tripped off and numerous Lights and Master Warning (Auto Pilot kicked off) associated with the following lights on the overhead panel: L GEN CONT 'OFF' LIGHT; L BUS 'BUS OFF' LIGHT; and BUS TIE 'ISLN' LIGHT. Captain returned from lavatory and worked with First Officer; who started the APU to try to restore lost systems including Transponder which ATC notified was not sending. We went through the checklist for L GEN CONT. Systems were restored. While talking to Maintenance Control and Dispatch we reviewed the checklist and agreed that the ONE reset was allowed per the checklist; and with all systems restored we continued to destination without further issues.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	912638
Time
Date	201010
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Aircraft 1
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Component
Aircraft Component	AC Generation
Person 1
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Total 15500 Flight Crew Type 5200
Events
Anomaly	Aircraft Equipment Problem Less Severe

B757 captain reported that while he was out of the flight deck; the aircraft had electrical anomalies. The left generator shuts down and the left bus becomes unpowered. After returning to the cockpit the generator is successfully reset using the checklist.