Narrative:

After arriving at the aircraft in ZZZ to operate flight ZZZ to ZZZ, the ground crew connected ground power. I turned on the aircraft lights and all the lights illuminated. Several mins later, the ground power flickered on and off, then remained off. After starting the APU, the flight attendant notified me that the potable water system, galley light and lavatory lights were inoperative. I checked the circuit breakers in the galley area and then all 4 circuit breaker panels in the cockpit. No circuit breakers were popped. I notified maintenance control of the discrepancy. He said, 'it sounds like you have a bunch of burned out bulbs.' I explained about the ground power and asked if these things could all be on the same bus. He said, 'no.' he said, 'these lights burn out all the time.' I told him that I had some experience with this a couple of yrs ago and thought that these things were connected. However, he asked me to defer all 3 items, which we did. On pushback, after selecting the #1 panel, generator on, a dc service bus caution message appeared. I asked the first officer to check the circuit breakers along with me and none were tripped. We returned to the gate and called maintenance control. He asked if the dc service switches were selected and I said no. He said, are you sure? I told him that I would go and double check. All switches were in the normal position. He asked if any of the ties were selected and I told him no. He said are you sure? Again, I told him I would go and double check. All AC and dc ties were in normal position. Contract maintenance was called. Contract maintenance arrived and was pulling a series of circuit breakers on panel #2 while on the phone with maintenance control. I watched the dc service bus circuit breaker pop when he pulled circuit breaker 2 rows below it right in front of his face. He said that he did not see that. Contract maintenance relayed that the dc service circuit breaker was tripped. I spoke up and said that it just popped 5 seconds ago. He told that information to maintenance control on the phone. He proceeded to sign off the logbook. I suggested testing the generators to see if it would pop again. We did the operations check good. I spoke and again asked if these lights were on the same bus and he avoided the question and said I gave him bad information. He said that the circuit breaker was probably popped all along. I corrected him and explained the numerous times that we checked the circuit breakers and that I watched it pop while the maintenance technician was standing 12 inches away from it. Contract maintenance wrote in the corrective action that the circuit breaker was found tripped upon arrival to the aircraft. This is intentional falsification of the maintenance logbook and there is a recorded phone call to prove it. Chief pilot was contacted and the tapes were pulled. This is a severe safety problem when the maintenance control and the contract maintenance lies to sign off an aircraft for flight. Once I returned to the aircraft, the circuit breaker popped again when the APU generator was selected on. I notified maintenance and service operations and deferred. A flight delay of 2 hours and 35 mins occurred. I believe that if maintenance worked together with the flight crew, instead of blaming, we would have a much safer operation. Callback conversation with reporter revealed the following information: the reporter stated that after all the running around the maintenance people got the idea the dc service bus had a fault. The reporter said the fix was pulling and capping the circuit breaker and deferring the item.

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Original NASA ASRS Text

Title: A CANADAIR CL65 HAD A DC SVC BUS CIRCUIT BREAKER TRIP. CONTRACT MAINT AND MAINT CTLR IN CONTENTION OVER WHEN CIRCUIT BREAKER TRIPPED.

Narrative: AFTER ARRIVING AT THE ACFT IN ZZZ TO OPERATE FLT ZZZ TO ZZZ, THE GND CREW CONNECTED GND PWR. I TURNED ON THE ACFT LIGHTS AND ALL THE LIGHTS ILLUMINATED. SEVERAL MINS LATER, THE GND PWR FLICKERED ON AND OFF, THEN REMAINED OFF. AFTER STARTING THE APU, THE FLT ATTENDANT NOTIFIED ME THAT THE POTABLE WATER SYS, GALLEY LIGHT AND LAVATORY LIGHTS WERE INOP. I CHKED THE CIRCUIT BREAKERS IN THE GALLEY AREA AND THEN ALL 4 CIRCUIT BREAKER PANELS IN THE COCKPIT. NO CIRCUIT BREAKERS WERE POPPED. I NOTIFIED MAINT CTL OF THE DISCREPANCY. HE SAID, 'IT SOUNDS LIKE YOU HAVE A BUNCH OF BURNED OUT BULBS.' I EXPLAINED ABOUT THE GND PWR AND ASKED IF THESE THINGS COULD ALL BE ON THE SAME BUS. HE SAID, 'NO.' HE SAID, 'THESE LIGHTS BURN OUT ALL THE TIME.' I TOLD HIM THAT I HAD SOME EXPERIENCE WITH THIS A COUPLE OF YRS AGO AND THOUGHT THAT THESE THINGS WERE CONNECTED. HOWEVER, HE ASKED ME TO DEFER ALL 3 ITEMS, WHICH WE DID. ON PUSHBACK, AFTER SELECTING THE #1 PANEL, GENERATOR ON, A DC SVC BUS CAUTION MESSAGE APPEARED. I ASKED THE FO TO CHK THE CIRCUIT BREAKERS ALONG WITH ME AND NONE WERE TRIPPED. WE RETURNED TO THE GATE AND CALLED MAINT CTL. HE ASKED IF THE DC SVC SWITCHES WERE SELECTED AND I SAID NO. HE SAID, ARE YOU SURE? I TOLD HIM THAT I WOULD GO AND DOUBLE CHK. ALL SWITCHES WERE IN THE NORMAL POS. HE ASKED IF ANY OF THE TIES WERE SELECTED AND I TOLD HIM NO. HE SAID ARE YOU SURE? AGAIN, I TOLD HIM I WOULD GO AND DOUBLE CHK. ALL AC AND DC TIES WERE IN NORMAL POS. CONTRACT MAINT WAS CALLED. CONTRACT MAINT ARRIVED AND WAS PULLING A SERIES OF CIRCUIT BREAKERS ON PANEL #2 WHILE ON THE PHONE WITH MAINT CTL. I WATCHED THE DC SVC BUS CIRCUIT BREAKER POP WHEN HE PULLED CIRCUIT BREAKER 2 ROWS BELOW IT RIGHT IN FRONT OF HIS FACE. HE SAID THAT HE DID NOT SEE THAT. CONTRACT MAINT RELAYED THAT THE DC SVC CIRCUIT BREAKER WAS TRIPPED. I SPOKE UP AND SAID THAT IT JUST POPPED 5 SECONDS AGO. HE TOLD THAT INFO TO MAINT CTL ON THE PHONE. HE PROCEEDED TO SIGN OFF THE LOGBOOK. I SUGGESTED TESTING THE GENERATORS TO SEE IF IT WOULD POP AGAIN. WE DID THE OPS CHK GOOD. I SPOKE AND AGAIN ASKED IF THESE LIGHTS WERE ON THE SAME BUS AND HE AVOIDED THE QUESTION AND SAID I GAVE HIM BAD INFO. HE SAID THAT THE CIRCUIT BREAKER WAS PROBABLY POPPED ALL ALONG. I CORRECTED HIM AND EXPLAINED THE NUMEROUS TIMES THAT WE CHKED THE CIRCUIT BREAKERS AND THAT I WATCHED IT POP WHILE THE MAINT TECHNICIAN WAS STANDING 12 INCHES AWAY FROM IT. CONTRACT MAINT WROTE IN THE CORRECTIVE ACTION THAT THE CIRCUIT BREAKER WAS FOUND TRIPPED UPON ARR TO THE ACFT. THIS IS INTENTIONAL FALSIFICATION OF THE MAINT LOGBOOK AND THERE IS A RECORDED PHONE CALL TO PROVE IT. CHIEF PLT WAS CONTACTED AND THE TAPES WERE PULLED. THIS IS A SEVERE SAFETY PROB WHEN THE MAINT CTL AND THE CONTRACT MAINT LIES TO SIGN OFF AN ACFT FOR FLT. ONCE I RETURNED TO THE ACFT, THE CIRCUIT BREAKER POPPED AGAIN WHEN THE APU GENERATOR WAS SELECTED ON. I NOTIFIED MAINT AND SVC OPS AND DEFERRED. A FLT DELAY OF 2 HRS AND 35 MINS OCCURRED. I BELIEVE THAT IF MAINT WORKED TOGETHER WITH THE FLT CREW, INSTEAD OF BLAMING, WE WOULD HAVE A MUCH SAFER OP. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THAT AFTER ALL THE RUNNING AROUND THE MAINT PEOPLE GOT THE IDEA THE DC SVC BUS HAD A FAULT. THE RPTR SAID THE FIX WAS PULLING AND CAPPING THE CIRCUIT BREAKER AND DEFERRING THE ITEM.

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.