A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Owning
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Transient alternator problem



 
 
Thread Tools Display Modes
  #1  
Old July 7th 04, 04:01 AM
John Clonts
external usenet poster
 
Posts: n/a
Default Transient alternator problem


"Jeremy Lew" wrote in message
...
Was flying IFR in the clear on top of an overcast layer today. I noticed

at
some point that the ammeter was indicating zero, and not moving. The Alt
warning light was not illuminated, except when I pressed the test button.

I
started to shut down non-essential electriconics in case this was for

real.
After a minute or two, the ammeter needle resumed normal indications, and
stayed that way for the rest of the flight. The Alt warning light was
properly illumated during low-RPM operations on the ground, as well as
during the engine runup split switch check.

The warning light/ammeter needle discrepancy suggests to me that problem

was
in the ammeter, and that the alternator was functioning normally the whole
time. Anyone have any theories as to what would cause indications like
this? Is external RF interference possible?

(x-posted to rec.aviation.owning)

What a coincidence, we've had the same sort of intermittent problem with our
charging system on the last few flights! Of course, when we've had our
voltmeter there to diagnose it, it seems to work perfectly

Will let you know what we find-- please do likewise!

(Ours is a 1978 Cessna 210M - IO520).

Cheers,
John Clonts
Temple, Texas
N7NZ



  #2  
Old July 7th 04, 01:38 PM
Jeremy Lew
external usenet poster
 
Posts: n/a
Default

Ours is a '78 Warrior (PA-28-151/161).
According to our maintenance officer, the ALT warning light and zero ammeter
reading during low rpm (~1000) ground operations is actually not normal. It
did make me pause for a minute, but then I figured I was being paranoid
since I don't usually look at either of those indicators until the 2000 rpm
runup, when both of those indicators were normal.

We have a new alternator on order, I'll let you know what our outcome is
too.

Jeremy

"John Clonts" wrote in message
...

"Jeremy Lew" wrote in message
...
Was flying IFR in the clear on top of an overcast layer today. I

noticed
at
some point that the ammeter was indicating zero, and not moving. The

Alt
warning light was not illuminated, except when I pressed the test

button.
I
started to shut down non-essential electriconics in case this was for

real.
After a minute or two, the ammeter needle resumed normal indications,

and
stayed that way for the rest of the flight. The Alt warning light was
properly illumated during low-RPM operations on the ground, as well as
during the engine runup split switch check.

The warning light/ammeter needle discrepancy suggests to me that problem

was
in the ammeter, and that the alternator was functioning normally the

whole
time. Anyone have any theories as to what would cause indications like
this? Is external RF interference possible?

(x-posted to rec.aviation.owning)

What a coincidence, we've had the same sort of intermittent problem with

our
charging system on the last few flights! Of course, when we've had our
voltmeter there to diagnose it, it seems to work perfectly

Will let you know what we find-- please do likewise!

(Ours is a 1978 Cessna 210M - IO520).

Cheers,
John Clonts
Temple, Texas
N7NZ





  #3  
Old July 7th 04, 01:41 PM
Dave Butler
external usenet poster
 
Posts: n/a
Default

FWIW, on the '75 Archer I used to own, the ammeter needle would sometimes stick
against the faceplate and not move. The mechanic bent the needle a little bit so
it wouldn't drag against the faceplate. The bent needle looked like crap, but it
worked after that.

Dave

Jeremy Lew wrote:
Ours is a '78 Warrior (PA-28-151/161).
According to our maintenance officer, the ALT warning light and zero ammeter
reading during low rpm (~1000) ground operations is actually not normal. It
did make me pause for a minute, but then I figured I was being paranoid
since I don't usually look at either of those indicators until the 2000 rpm
runup, when both of those indicators were normal.

We have a new alternator on order, I'll let you know what our outcome is
too.

Jeremy

"John Clonts" wrote in message
...

"Jeremy Lew" wrote in message
...

Was flying IFR in the clear on top of an overcast layer today. I


noticed

at

some point that the ammeter was indicating zero, and not moving. The


Alt

warning light was not illuminated, except when I pressed the test


button.

I

started to shut down non-essential electriconics in case this was for


real.

After a minute or two, the ammeter needle resumed normal indications,


and

stayed that way for the rest of the flight. The Alt warning light was
properly illumated during low-RPM operations on the ground, as well as
during the engine runup split switch check.

The warning light/ammeter needle discrepancy suggests to me that problem


was

in the ammeter, and that the alternator was functioning normally the


whole

time. Anyone have any theories as to what would cause indications like
this? Is external RF interference possible?


(x-posted to rec.aviation.owning)

What a coincidence, we've had the same sort of intermittent problem with


our

charging system on the last few flights! Of course, when we've had our
voltmeter there to diagnose it, it seems to work perfectly

Will let you know what we find-- please do likewise!

(Ours is a 1978 Cessna 210M - IO520).

Cheers,
John Clonts
Temple, Texas
N7NZ








--
Dave Butler, software engineer 919-392-4367

  #4  
Old July 7th 04, 05:19 PM
Jeremy Lew
external usenet poster
 
Posts: n/a
Default

My needle moved to zero during cruise flight, so I don't think it could be
the case for me.

Jeremy

"Dave Butler" wrote in message
...
FWIW, on the '75 Archer I used to own, the ammeter needle would sometimes

stick
against the faceplate and not move. The mechanic bent the needle a little

bit so
it wouldn't drag against the faceplate. The bent needle looked like crap,

but it
worked after that.

Dave

Jeremy Lew wrote:
Ours is a '78 Warrior (PA-28-151/161).
According to our maintenance officer, the ALT warning light and zero

ammeter
reading during low rpm (~1000) ground operations is actually not normal.

It
did make me pause for a minute, but then I figured I was being paranoid
since I don't usually look at either of those indicators until the 2000

rpm
runup, when both of those indicators were normal.

We have a new alternator on order, I'll let you know what our outcome is
too.

Jeremy

"John Clonts" wrote in message
...

"Jeremy Lew" wrote in message
...

Was flying IFR in the clear on top of an overcast layer today. I

noticed

at

some point that the ammeter was indicating zero, and not moving. The

Alt

warning light was not illuminated, except when I pressed the test

button.

I

started to shut down non-essential electriconics in case this was for

real.

After a minute or two, the ammeter needle resumed normal indications,

and

stayed that way for the rest of the flight. The Alt warning light was
properly illumated during low-RPM operations on the ground, as well as
during the engine runup split switch check.

The warning light/ammeter needle discrepancy suggests to me that

problem

was

in the ammeter, and that the alternator was functioning normally the

whole

time. Anyone have any theories as to what would cause indications like
this? Is external RF interference possible?


(x-posted to rec.aviation.owning)

What a coincidence, we've had the same sort of intermittent problem with


our

charging system on the last few flights! Of course, when we've had our
voltmeter there to diagnose it, it seems to work perfectly

Will let you know what we find-- please do likewise!

(Ours is a 1978 Cessna 210M - IO520).

Cheers,
John Clonts
Temple, Texas
N7NZ








--
Dave Butler, software engineer 919-392-4367



  #5  
Old July 7th 04, 06:40 PM
Jim Weir
external usenet poster
 
Posts: n/a
Default

Had the same thing on the 182 about ten years ago. Drove me nuts for about a
week until I noticed that the throttle control was adjacent to the diode plate
on the rear of the alternator. Spreading the two apart, you could clearly see
where the throttle cable insulation was chafed through and touching the diode
plate, killing the alternator. Of course, on the ground with the engine torque
not moving the alternator just that few thousandths of an inch that made
contact, it wouldn't do it for love nor money except when the airplane was
actually flying.

Run your hand all the way around the rear diode plate on the alternator and see
if there is a cable nearby.

Jim


Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com
  #6  
Old July 8th 04, 06:49 PM
John Stevens
external usenet poster
 
Posts: n/a
Default

Dave Butler wrote in message ...
FWIW, on the '75 Archer I used to own, the ammeter needle would sometimes stick
against the faceplate and not move. The mechanic bent the needle a little bit so
it wouldn't drag against the faceplate. The bent needle looked like crap, but it
worked after that.

Dave


The correct term (so as not to scare the uninitiated) is "formed" not
"bent". Your mechanic "formed the needle a little bit". So it was
explained to me by an ex-IBM ield engineer, anyway.

John S.
  #7  
Old July 11th 04, 06:01 PM
Jeremy Lew
external usenet poster
 
Posts: n/a
Default

Alternator was removed and found to have worn brushes and somewhat corroded,
stiff springs. It was 5.5 years and 620 hours old, and was replaced with a
new one. It is believed that the brush condition was responsible for the
intermittant contact.

Jeremy

"John Clonts" wrote in message
...

"Jeremy Lew" wrote in message
...
Was flying IFR in the clear on top of an overcast layer today. I

noticed
at
some point that the ammeter was indicating zero, and not moving. The

Alt
warning light was not illuminated, except when I pressed the test

button.
I
started to shut down non-essential electriconics in case this was for

real.
After a minute or two, the ammeter needle resumed normal indications,

and
stayed that way for the rest of the flight. The Alt warning light was
properly illumated during low-RPM operations on the ground, as well as
during the engine runup split switch check.

The warning light/ammeter needle discrepancy suggests to me that problem

was
in the ammeter, and that the alternator was functioning normally the

whole
time. Anyone have any theories as to what would cause indications like
this? Is external RF interference possible?

(x-posted to rec.aviation.owning)

What a coincidence, we've had the same sort of intermittent problem with

our
charging system on the last few flights! Of course, when we've had our
voltmeter there to diagnose it, it seems to work perfectly

Will let you know what we find-- please do likewise!

(Ours is a 1978 Cessna 210M - IO520).

Cheers,
John Clonts
Temple, Texas
N7NZ





 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT +1. The time now is 10:09 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2023, Jelsoft Enterprises Ltd.
Copyright 2004-2023 AviationBanter.
The comments are property of their posters.