user9253
Joined: 28 Mar 2008
Posts: 1908
Location: Riley TWP Michigan
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 Posted: Sun Jan 25, 2015 5:16 pm Post subject: FMEA |
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| Quote: | . . . okay, step through the FMEA for a shorted cell in
any battery. How will the event manifest? How will the
pilot become aware of it? What is the recommended plan
of action to be taken by the pilot? Most important . . .
what features can be incorporated into the full-up system
to offer a pilot the best response to the event? |
Good suggestion and worthy of a new thread. A shorted AGM battery is highly unlikely. But I think the symptoms would be low system voltage and high current on the ammeter no matter if the shunt measures battery current or alternator output. Of course the pilot would not know what the problem is. There could be a short external to the battery (which is more likely). The prudent thing to do would be to shut off the master switch and land to investigate the problem.
Another interesting failure is of the master contactor coil. How will the pilot know? If the alternator keeps working, which is likely, then there might not be any clues. The voltage will remain the same. An alternator load meter will not change much. An ammeter that measures battery charge-discharge current will be on zero, not far from where it usually is. The pilot might not realize the contactor coil failed until he closes the throttle or maybe not until the next engine start.
It would be worthwhile to analyze each component of the electrical system and ask, if this part fails, how will I know and what should I do about it.
Joe
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Joe Gores |
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