REFLECTOR: Alternator Field

[Rene Dugas]

Dear fellows,

I flew from Houston to north Louisiana on  Sunday.  My Alt. Field
Circuit Breaker opened three times on the flight.  The Vision picked it
up within 3 seconds.  I pressed it in again and flew without event for
about 30 minutes and it popped again.  I noticed that the gear pump
cycled at the same time(yellow motor run light momentarily illuminated).
I checked the bulbs on the gear indicator and cycled the pump without
event.  No problems for 20 minutes and it popped again.  Pushed it in
and continued to charge at usual 12 amps.  Upon landing no problems with
gear motor running with strobes and pitot heat on at 47 amps.  Checked
wire to alt. no burns or evidence of short.  I've been told the spring
in the CB can get weak causing inappropriate opening.  I feel this may
be related to my pump not being able to spin with significant slack in
the gear play causing an electric motor unable to move condition causing
a high draw condition.  Just a feeling.  I am not an EE!  Ideas on order
of tests or start replacing parts - CB, wiring, Alt., Etc.  Is there a
condition in the alternator that will cause this and can I check for it?
I jacked my plane up and my gear will cycle about each 20 to 30 minutes
which matches the frequency of the problem.  I can not run it on jacks
to test.  I had the CB open twice before in 250 hrs and reran the wire.
No problem in over 150 hrs.

Ideas?

Rene'

 

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