Narrative:

In cruise 2 hours after takeoff EICAS 'center tanks low' came on. Turned pumps off but rt center tank low press light stayed on indicating that the pump was still running. Fuel synoptic had green box around rt center pump indicating it was still running. Pulled up FMC maintenance and observed pump was still running. Looked at mat existing defects and observed 'fault/failure rt center tank pump switch.' called maintenance control with all the above. Consulted all aircraft checklists; FM normal; non-normal; emergencies and found no relevant info or guidance. Conference call with maintenance control; dispatch; and duty manager. I expressed great concern over a fuel pump running that I could not shut off; in an empty fuel tank that has not been modified with an inerting system. Concern over dry fuel pump overheating was indicated by all crew members. Maintenance control advised that ...pulling...the l2p210 circuit breaker would remove power from the switch; the ARINC629 bus that controls the cards for fuel pump control and the pump would shut off. The fom was consulted. The flight manual limits page did not prohibit...pulling...of the P21o L2 circuit breaker. I advised maintenance control and dispatch; that I would use 'captain emergency authority' to pull the circuit breaker. Relief pilot and flying first officer were briefed and flying first officer designated captain. I entered east+east bay and pulled circuit breaker. Fuel synoptic; FMC maintenance page and mat all confirmed pump was now deactivated. The aircraft was now operationally normal. Maintenance; dispatch and duty manager were all consulted and it was agreed to continue to our planned destination. Thirty minutes later the duty manager called and ordered divert to an enroute station per 'fleet' and an emergency was declared. Dumped fuel landed. Refilled; fueled; and pushed. Ramp called to return to gate. The chief pilot advised crew removed from trip and deadhead home tomorrow.

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Original NASA ASRS Text

Title: A B777 EICAS alerted CTR TANKS LOW; but the right center tank would not turn off. The circuit breaker was pulled but because that procedure was not authorized; the Duty Manager diverted the aircraft and removed the crew.

Narrative: In cruise 2 hours after takeoff EICAS 'CTR TANKS LOW' came on. Turned pumps off but RT CTR TANK LOW PRESS light stayed on indicating that the pump was still running. Fuel Synoptic had Green box around RT CTR pump indicating it was still running. Pulled up FMC Maintenance and observed pump was still running. Looked at MAT Existing Defects and observed 'FAULT/FAILURE RT CTR TANK PUMP SWITCH.' Called Maintenance Control with all the above. Consulted all aircraft checklists; FM Normal; non-normal; emergencies and found no relevant info or guidance. Conference call with Maintenance Control; Dispatch; and Duty Manager. I expressed great concern over a fuel pump running that I could not shut off; in an empty fuel tank that has not been modified with an inerting system. Concern over dry fuel pump overheating was indicated by all crew members. Maintenance Control advised that ...PULLING...the L2P210 CB would remove power from the switch; the ARINC629 bus that controls the cards for fuel pump control and the pump would shut off. The FOM was consulted. The Flight Manual Limits page did not prohibit...PULLING...of the P21o L2 CB. I advised Maintenance Control and Dispatch; that I would use 'CAPT EMERGENCY AUTHORITY' to pull the CB. Relief pilot and flying First Officer were briefed and Flying First Officer designated Captain. I entered E+E bay and pulled CB. Fuel synoptic; FMC Maintenance page and MAT all confirmed pump was now deactivated. The aircraft was now operationally normal. Maintenance; Dispatch and Duty Manager were all consulted and it was agreed to continue to our planned destination. Thirty minutes later the Duty Manager called and ordered divert to an enroute station per 'FLEET' and an EMERGENCY was declared. Dumped fuel landed. Refilled; fueled; and pushed. Ramp called to return to gate. The Chief Pilot advised crew removed from trip and deadhead home tomorrow.

Data retrieved from NASA's ASRS site as of July 2013 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.