VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #41  
Old 09-28-2016, 02:19 PM
SmilingJack's Avatar
SmilingJack SmilingJack is offline
 
Join Date: Dec 2010
Location: Naples,FL
Posts: 880
Default

Thanks Bill! I'll be doing the upgrade as soon as the new parts come!
__________________
John Mastro
RV-8
Reply With Quote
  #42  
Old 12-27-2016, 12:17 PM
Raven31 Raven31 is offline
 
Join Date: May 2009
Location: Portales NM
Posts: 26
Default

Jim,

Did you ever find the issue with this problem?
Reply With Quote
  #43  
Old 12-27-2016, 12:18 PM
Raven31 Raven31 is offline
 
Join Date: May 2009
Location: Portales NM
Posts: 26
Default Solution?

Quote:
Originally Posted by jimgreen View Post
This is also a timely thread for me.
I have a PP 60 amp alternator with the idiot light. My ammeter only shows bus amps, not total amps. My PC680 battery is only about 6 months old.
Recently I notice the idiot light showing dimly at about 1200rpm and 14 amps.
At 28 amps the light is full red but the voltage shows 13v.
At 28amps and 2100-2400 rpm the light is on dimly even though the voltage is showing 13.9-14.1
First thought was loose belt, and it was a little loose but I adjusted it to the high end of the range and no change.

It doesn't make sense to me that I show plenty of voltage to be charging the battery and yet have a red light on. How is that idiot light wired exactly?

Ever find the issue?
Reply With Quote
  #44  
Old 12-27-2016, 05:16 PM
jimgreen jimgreen is offline
 
Join Date: Apr 2006
Location: Vancouver island, BC Canada
Posts: 360
Default

At PP's suggestion I replaced the voltage regulator unit which includes the brushes. This made no difference to the behaviour of the red light, but there was a change in the way the regulator behaved. It seems more 'dead beat' than the old one. It ramps up the voltage much more slowly and also puts out a lower voltage at low rpm.
I plan to remove the alternator and get it tested. Our local shop was too backed up at the time but I'll give it a go when I have the cowling off next.
I can't fault its performance, but that light should not be flickering.

Did you have a similar problem?
Jim
__________________
Jim Green
RV7 tip up
IO360 Whirlwind 200RV
Building RV8 with buddy
Reply With Quote
  #45  
Old 12-27-2016, 08:24 PM
Raven31 Raven31 is offline
 
Join Date: May 2009
Location: Portales NM
Posts: 26
Default

Quote:
Originally Posted by jimgreen View Post
At PP's suggestion I replaced the voltage regulator unit which includes the brushes. This made no difference to the behaviour of the red light, but there was a change in the way the regulator behaved. It seems more 'dead beat' than the old one. It ramps up the voltage much more slowly and also puts out a lower voltage at low rpm.
I plan to remove the alternator and get it tested. Our local shop was too backed up at the time but I'll give it a go when I have the cowling off next.
I can't fault its performance, but that light should not be flickering.

Did you have a similar problem?
Jim
Yeah the other night flying home for Christmas .. it flickered and then stayed on steady with 14.6 volts and 2 amps.. I found a broken ring terminal on the main airplane ground cable engine to airframe and thought that was it .. I replaced that terminal and still have an alternator light on .. tested many things today and still have the light .. I turned every electrical switch on and it still maintains 14.4 volts and 2-3 amps. I'm stumped.
Reply With Quote
  #46  
Old 04-20-2017, 07:53 AM
Rupester Rupester is offline
 
Join Date: Dec 2005
Location: Mahomet, Illinois
Posts: 2,127
Default

Recently, my low voltage light light began to appear frequently, on and off, for the better part of an hour. When I went to the EFIS engine page, the voltage was fluctuating up and down from 12.6V to 12.1. ( the alarm limit 12.0). No matter how long I watched, the voltage never stayed steady, it was constantly up and down across 0.5V spread, almost sinusoidal in pattern. I could see the alarm sound whenever the voltage dropped below 12. Turning on the boost pump dropped the bottom voltage in the fluctuation to 11.9V, then it would stay in alarm until acknowledged nearly.
My voltage is measured at GRT EFIS display #1, and due to the Schottkey diode (AeroElectrics Z-11), always shows less than 13.0 volts.

- Battery voltage checked fine (PC680 only 5 mo's old), as did field voltage at the Plane Power 60A alt, and supply voltage at the B+ terminal.
- Belt tension is fine per torque spec.
- I have tug-tested all wire connections, especially those at the Plane Power plug. No loose connections found.
- Had the alternator tested at a local alternator shop .... they found no problems.

Will now install a new 3-terminal plug a la Dan's discovery. Fingers crossed that takes care of the issue.
__________________
Terry Ruprecht
RV-9A Tip-up; IO-320 D2A
S. James cowl/plenum
(Dues paid thru Nov '17)
Reply With Quote
  #47  
Old 04-20-2017, 06:19 PM
gasman gasman is offline
 
Join Date: Mar 2007
Location: Sonoma County
Posts: 3,211
Default

Quote:
Originally Posted by Rupester View Post
Recently, my low voltage light light began to appear frequently, on and off, for the better part of an hour. When I went to the EFIS engine page, the voltage was fluctuating up and down from 12.6V to 12.1. ( the alarm limit 12.0). No matter how long I watched, the voltage never stayed steady, it was constantly up and down across 0.5V spread, almost sinusoidal in pattern. I could see the alarm sound whenever the voltage dropped below 12. Turning on the boost pump dropped the bottom voltage in the fluctuation to 11.9V, then it would stay in alarm until acknowledged nearly.
My voltage is measured at GRT EFIS display #1, and due to the Schottkey diode (AeroElectrics Z-11), always shows less than 13.0 volts.

- Battery voltage checked fine (PC680 only 5 mo's old), as did field voltage at the Plane Power 60A alt, and supply voltage at the B+ terminal.
- Belt tension is fine per torque spec.
- I have tug-tested all wire connections, especially those at the Plane Power plug. No loose connections found.
- Had the alternator tested at a local alternator shop .... they found no problems.

Will now install a new 3-terminal plug a la Dan's discovery. Fingers crossed that takes care of the issue.
Set your alarm limit to 13 so you will be notified when the alternator fails. With it set at 12 volts, you are notified that your BATTERY is now at 25% and your safety margin is gone.

If my alternator fails and I see it at 13 volts, my battery will out last my fuel supply.
__________________
VAF #897
2016 =VAF= Dues PAID
Reply With Quote
  #48  
Old 04-21-2017, 01:08 PM
Kingfish Kingfish is offline
 
Join Date: Oct 2012
Location: Westfield, IN
Posts: 3
Default buss connection

Hi Terry

I had a very similar experience and replaced a perfectly good alternator only to find the real problem was a slightly loose screw securing the positive cable connector to the positive buss.

Worth checking.

Mike
Reply With Quote
  #49  
Old 04-22-2017, 12:25 PM
Rupester Rupester is offline
 
Join Date: Dec 2005
Location: Mahomet, Illinois
Posts: 2,127
Default

Thanks, Mike. That was in my first round of connection checks. 😉
__________________
Terry Ruprecht
RV-9A Tip-up; IO-320 D2A
S. James cowl/plenum
(Dues paid thru Nov '17)
Reply With Quote
  #50  
Old 05-03-2017, 05:38 PM
Rupester Rupester is offline
 
Join Date: Dec 2005
Location: Mahomet, Illinois
Posts: 2,127
Default Update

Put the bird back together and flew for 1.0 today. Charging system worked perfectly .... just like prior to the problem on 4/12. The puzzling part is why it's performing well. Here's the scoop:
- 60A PP alternator bench tested fine at the alternator shop
- I did not replace the Sumitomo 3 contact plug. I looked closely at both the new one I ordered and the one still on the airplane. I could see little benefit to replacing with an identical-in-very-way new plug. The prongs on the alternator were not corroded and looked fine, as did the plug's female sockets. Decided to reassemble and fly; if the problem was still there, THEN I would replace the 3-wire plug.
- tug tested all connections a second time... found nothing
- cleaned both pulleys with MEK to reduce the possibility of slippage
- carefully examined the existing belt ... looked fine
- put it all back together; tightened the alt belt to the same torque as before, 8 ft-lbs.

And today the previous problem was magically gone. That implies it was either a slipping belt or a flaky 3-contact plug (that worked fine when re-inserted). I'm betting it's the latter vs the former. Time will tell.
__________________
Terry Ruprecht
RV-9A Tip-up; IO-320 D2A
S. James cowl/plenum
(Dues paid thru Nov '17)
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 -6. The time now is 10:34 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.