AN MD11 IN CRUISE AT FL350 DIVERTED DUE TO STRONG ODOR OF OVERHEATED ELECTRICAL EQUIP CAUSED BY THE MALFUNCTION OF THE WATER PRESSURE COMPRESSOR MOTOR.

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IN CRUISE WE SMELLED A STRONG ODOR OF SOMETHING BURNING LIKE ELECTRICAL OR EQUIP. WE DIVERTED OFF TRACK; DSNDED TO FL270; AND PRECEDED DIRECT TO SHANNON (EINN); IRELAND ARPT. THE RELIEF PLT DID THE 'SMOKE/FUMES OF ELECTRICAL; AIR CONDITIONING; OR UNKNOWN SOURCE' CHKLIST AND WAS ABLE TO ISOLATE PROB AND ODOR DECREASED. I WAS FLYING AND WITH DOING THE CHKLIST I LOST MY INSTS (WHICH IS SUPPOSED TO HAPPEN WITH THE ABNORMAL CHKLIST) AND THE CAPT THEN FLEW TO SHANNON. WE HAD A NORMAL LNDG AT SHANNON. MAINT FOUND A WATER PRESSURE PUMP THAT SEIZED AND OVERHEATED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE CAUSE OF THE ELECTRICAL SMELL WAS THE FLEXIBLE RUBBER WATER COMPRESSOR DRIVE BELT AND THE OVERHEATED ELECTRICAL MOTOR WHICH WAS OPERATING CONTINUOUSLY. THE RPTR SAID THE WATER TANK AIR COMPRESSOR ONLY OPERATES ON THE GND AND ONLY WITH NO OTHER SOURCE OF PNEUMATIC AIR; APU; ENG OR GND AIR CART. THE RPTR SAID THE MALFUNCTION WAS SUSPECTED IN THE FAILED TANK PRESSURE SWITCH OR A LEAK IN THE FLEXIBLE HOSE SENSING PRESSURE IN THE TANK ALLOWING THE MOTOR TO RUN CONTINUOUSLY. THE SMELL WAS CAUSED MAINLY BY THE RUBBER DRIVE BELT THAT WAS CHEWED UP STALLED THE MOTOR WHICH OVERHEATED AND TRIPPED THE CIRCUIT BREAKER IN THE CABIN. THE RPTR SAID THE LOSS OF THE FO'S INSTS WAS CAUSED BY THE CHKLIST PROC TO ISOLATE THE ELECTRICAL BUSSES AND THE WATER PRESSURE COMPRESSOR WAS ON THE #3 BUS WHICH ALSO FEEDS THE FO'S INSTS.IN CRUISE WE SMELLED A STRONG ODOR OF SOMETHING BURNING LIKE ELECTRICAL OR EQUIP. WE DIVERTED OFF TRACK; DSNDED TO FL270; AND PROCEEDED DIRECT TO SHANNON (EINN); IRELAND ARPT. THE RELIEF PLT DID THE 'SMOKE/FUMES OF ELECTRICAL; AIR CONDITIONING; OR UNKNOWN SOURCE' CHKLIST AND WAS ABLE TO ISOLATE PROB AND ODOR DECREASED. I WAS FLYING AND WITH DOING THE CHKLIST I LOST MY INSTS (WHICH IS SUPPOSED TO HAPPEN WITH THE ABNORMAL CHKLIST) AND THE CAPT THEN FLEW TO SHANNON. WE HAD A NORMAL LNDG AT SHANNON. MAINT FOUND A WATER PRESSURE PUMP THAT SEIZED AND OVERHEATED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE CAUSE OF THE ELECTRICAL SMELL WAS THE FLEXIBLE RUBBER WATER COMPRESSOR DRIVE BELT AND THE OVERHEATED ELECTRICAL MOTOR WHICH WAS OPERATING CONTINUOUSLY. THE RPTR SAID THE WATER TANK AIR COMPRESSOR ONLY OPERATES ON THE GND AND ONLY WITH NO OTHER SOURCE OF PNEUMATIC AIR; APU; ENG OR GND AIR CART. THE RPTR SAID THE MALFUNCTION WAS SUSPECTED IN THE FAILED TANK PRESSURE SWITCH OR A LEAK IN THE FLEXIBLE HOSE SENSING PRESSURE IN THE TANK ALLOWING THE MOTOR TO RUN CONTINUOUSLY. THE SMELL WAS CAUSED MAINLY BY THE RUBBER DRIVE BELT THAT WAS CHEWED UP STALLED THE MOTOR WHICH OVERHEATED AND TRIPPED THE CIRCUIT BREAKER IN THE CABIN. THE RPTR SAID THE LOSS OF THE FO'S INSTS WAS CAUSED BY THE CHKLIST PROC TO ISOLATE THE ELECTRICAL BUSSES AND THE WATER PRESSURE COMPRESSOR WAS ON THE #3 BUS WHICH ALSO FEEDS THE FO'S INSTS.