During climb after takeoff; a B757 left gen/AC bus tie breaker opened. The QRH reset procedure recon...

Attributes
ACN	1393864
Time
Date	201610
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Component
Aircraft Component	APU
Person 1
Function	Pilot Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Total 8446 Flight Crew Type 6707
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 177 Flight Crew Total 9684 Flight Crew Type 5532
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Weight And Balance

Narrative:

As we departed; passing approximately 12;000 ft the left generator dropped off line. We requested a level off at 15;000 ft. I continued to fly the airplane and talk to ATC while the captain ran the checklist in the QRH. He reset the generator and the left side instruments came back on for about 3 minutes and then dropped off again. We started the APU and noticed the left bus tie had isolated the left side so it remained unpowered from either the right generator or the APU. I [advised ATC] and we were given a vector for the return to the departure airport. The captain coordinated with dispatch and maintenance control and ran the left AC bus off checklist. The captain selected the right side as the source for his instruments. We did not have autothrottles or the flap indicator for the approach and landing. We landed overweight at 247.5 when the max landing weight is 224; but it was a very smooth landing. We terminated the [situation]; and taxied into the gate where we were met by maintenance personnel and briefed them in full.

Original NASA ASRS Text

Title: During climb after takeoff; a B757 left GEN/AC BUS TIE Breaker opened. The QRH reset procedure reconnected the GEN for about 3 minutes; but after it opened again; the flight returned to the departure airport with an unpowered Left AC Bus.

Narrative: As we departed; passing approximately 12;000 ft the left generator dropped off line. We requested a level off at 15;000 ft. I continued to fly the airplane and talk to ATC while the Captain ran the checklist in the QRH. He reset the generator and the left side instruments came back on for about 3 minutes and then dropped off again. We started the APU and noticed the left bus tie had isolated the left side so it remained unpowered from either the right generator or the APU. I [advised ATC] and we were given a vector for the return to the departure airport. The Captain coordinated with Dispatch and Maintenance Control and ran the L AC Bus off checklist. The Captain selected the right side as the source for his instruments. We did not have autothrottles or the flap indicator for the approach and landing. We landed overweight at 247.5 when the max landing weight is 224; but it was a very smooth landing. We terminated the [situation]; and taxied into the gate where we were met by maintenance personnel and briefed them in full.

Data retrieved from NASA's ASRS site 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.

During climb after takeoff; a B757 left gen/AC bus tie breaker opened. The QRH reset procedure reconnected the gen for about 3 minutes; but after it opened again; the flight returned to the departure airport with an unpowered left AC bus.