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From: n295vv (n295 v v)

During the last trip I noticed that my EI meter was showing extreme surges in the amperage, while the voltage remained constant.  I was seeing 5.8 amps +0 -5.2 amps during its scan which is reporting in fractions of a second.  It was reporting practically all amps within this range.

At the suggestion of Don Goetz, I selectively pulled breakers in flight to isolate the problem, but was unable to figure it out.

The alternator had been recently overhauled do to an oil seal leak, and I considered it to be in excellent shape and not causing the problem.

Upon arriving back from my trip, I consulted Terry Norris of Aircraft Systems at Greater Rockford (Illinois) Airport (RFD), who has done all of my electrical overhaul work for several years, and who is a super technical guy.

He said to go through all of the electrical connections between the alternator, push-pull breakers, master switch, and key switch, and check to see that some screw has not loosened on a connection.  Simply stated, he says that a slightly loose screw will cause an increase in resistance in the circuit, which the electronic voltage controller will adapt to, which in turn will cause the amperage to jump, which in turn will.....anyway, you get the idea.

Yesterday, I found the the large screws on my main 80 amp breaker were very slightly loose, and I corrected them.  Terry Norris says that he finds that a 1/4 volt of voltage drop will be accomodated, but if the connection causes 1/2 volt, the electronic voltage controllers will cause surges such as I am seeing.

I will update you as soon as this weather clears and I get to test fly the plane.

David Jones
Pecatonica, Illinois

[Thanks for the report, David... it sounds like putting a screwdriver to
every electrical connection during annual inspection would be good idea.
Something folks should likely add to their annual checklist, irrespective
of the aircraft model.   <Marv>   ]

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