From: N295VV@aol.com
Message-ID: <ab79de6b.243b6608@aol.com>
Date: Tue, 6 Apr 1999 09:28:40 EDT
Subject: Re: Amperage surges--IV
To: lancair.list@olsusa.com
Reply-To: N295VV@aol.com
Mime-Version: 1.0

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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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