X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-px0-f198.google.com ([209.85.216.198] verified) by logan.com (CommuniGate Pro SMTP 5.3c4) with ESMTP id 4032221 for flyrotary@lancaironline.net; Sun, 20 Dec 2009 12:50:02 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.216.198; envelope-from=wdleonard@gmail.com Received: by pxi36 with SMTP id 36so3049236pxi.26 for ; Sun, 20 Dec 2009 09:49:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=WdpMEpV5539ejKlb0LddnpZzm7L3RYW4l5FbMgsvuxY=; b=WA068fEo/t1q1jZx4EwZsl2dLpX4hBlWwyXUWX0MrFnjC9OBAAesEVWFF06f15xnLN /WYVmctxL00u3lhRq+FsffGwkA57I6bQ2dctGuB0PknofiEIJkd5ZmQk+9DS+BRH/N8U 5dbUqLtAan+6ZN1LrUPoCwHaZoFVRCVIvqu84= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=SnsuDOq99j1uDX3dGFL95PtPkT4q9Jpa6TIjopcvjlKriojY1C1VXrGtjEqcNeHyfv hH5mmCLbybIeuUZNo65py640y0DMjpuYK0ScUMWcChI4EZrsYliKR4CQeJo133pBCaZI 5saL8kvEX/4l3SqAHpoau53UClcSn1BahgZq8= MIME-Version: 1.0 Received: by 10.142.250.7 with SMTP id x7mr4166487wfh.24.1261331365536; Sun, 20 Dec 2009 09:49:25 -0800 (PST) In-Reply-To: References: Date: Sun, 20 Dec 2009 09:49:25 -0800 Message-ID: <1c23473f0912200949k60441f74m452115dd130b8786@mail.gmail.com> Subject: Re: [FlyRotary] Re: Real Life No Alternator test From: David Leonard To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=001636ed69dafca5ad047b2c9721 --001636ed69dafca5ad047b2c9721 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable HI Al, yes, I have been considering that. My field is external like yours. In that supply I have a 10amp fuse and the switch itself, along with the necessary crimps on the spade connectors. I suppose I could tryed a temporary short across those connections to see if that that fixed the problem, but it did not. Also voltage measured at the field is the same as on my engine monitor. I wonder if we are wearing out the brushes more quickly because of our high continuous RPM. --=20 David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net On Sun, Dec 20, 2009 at 7:55 AM, Al Gietzen wrote: > Dave; > > > > Regarding the varying, or higher charging voltage, I=92ve had similar > behavior. I=92ve determined that a possible cause is the difference wher= e you > are measuring the voltage, and what the regulator is seeing. I provide t= he > field current from a separate source, having undone the internal connecti= on > from the alternator output. You may have a similar setup. That means that > any resistance =96 voltage drops =96 from the battery to the alternator f= ield, > will result in the regulator seeing a lower voltage, and increasing the > output. > > > > I have two potential contact resistance points in that circuit; the batte= ry > contactor, and a pullable breaker that I use to turnoff the field current= if > I want. A couple of weeks ago when I started up the voltage (at the EM2) > was reading over 15V, and triggering the over limit light. After a coupl= e > of resets of the breaker, and a couple of shutdowns (turning off battery > contactor), the voltage settled down at 14-14.5. > > > > I=92m not fully convinced the contacts were the problem, but I think it > likely. May be relevant to your situation. > > > > Early this year I had replaced the voltage regulator after seeing high > voltage. Next time I=92ll replace the pullable breaker or the battery > contactor. > > > > (I bet the skiing at mammoth was great, and the weather beautiful.) > > > > Al > > > > > > > > -----Original Message----- > *From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *O= n > Behalf Of *David Leonard > *Sent:* Saturday, December 19, 2009 5:52 PM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Real Life No Alternator test > > > > I have been having an intermittent and slowly worsening problem with high > voltage. Over most of the last 30 hrs or so it settled in around 14.6 or > 14.7 volts. But on yesterday's flight home from Mammoth I noticed it > hovering around 15V and some of my avionics were acting up, so I decided = to > do a little alternator out experiment. > > > > I turned off the alternator and all unnecessary draw - radio, strobes, Bl= ue > Mountain EFIS, electric AI. I kept on the engine instrumentation, > transponder, music (a most critical item given the beauty of the sunset), > audio panel, rocky mountain microencoder, and trio auto pilot (also allow= ing > me to more fully enjoy the flight). I was showing 8 amps to run the engin= e > bus (coils and injectors). > > > > With my 33 amp hour Panasonic SLA battery I flew for 45 minutes and 200 > miles over the Sierras, passing dozens of airports, and into the LA basin > before it got dark enough that I decided to turn the lights on. The plan > was to turn the alternator back on when the voltage dropped below 11.5 vo= lts > but it never dropped below 11.9V. It did charge at a brisk 60amps when I > turned the alternator back on so there couldn't have been too much time > left. Still, that did quite a bit of confidence building regarding the > ability to carry on in the event of an alternator failure. > > > > I also set a personal record for the most beautiful and clear sunset I ha= ve > seen while flying. I could see San Nicholas Island from over 150 miles > away. > > > > Time to install a spare alternator. > > > -- > David Leonard > > Turbo Rotary RV-6 N4VY > http://N4VY.RotaryRoster.net > http://RotaryRoster.net > --001636ed69dafca5ad047b2c9721 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
HI Al, yes, I have been considering that.=A0 My field is external like= yours.=A0 In that supply I have a 10amp fuse and the switch itself, along = with the necessary crimps on the spade connectors.=A0 I suppose I could try= ed a temporary short across those connections to see if that that fixed the= problem, but it did not.=A0 Also voltage measured at the field is the same= as on my engine monitor.
=A0
I wonder if we are wearing out the brushes more quickly because of our= high continuous RPM.
=A0
--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net


On Sun, Dec 20, 2009 at 7:55 AM, Al Gietzen <ALVentures@cox.net<= /a>> wrote:

Dave= ;

=A0<= /font>

Regarding t= he varying, or higher charging voltage, I=92ve had similar behavior.=A0 I= =92ve determined that a possible cause is the difference where you are meas= uring the voltage, and what the regulator is seeing. =A0I provide the field= current from a separate source, having undone the internal connection from= the alternator output. You may have a similar setup. That means that any r= esistance =96 voltage drops =96 from the battery to the alternator field, w= ill result in the regulator seeing a lower voltage, and increasing the outp= ut.

=A0<= /font>

I have two = potential contact resistance points in that circuit; the battery contactor,= and a pullable breaker that I use to turnoff the field current if I want. = =A0A couple of weeks ago when I started up the voltage (at the EM2) was rea= ding over 15V, and triggering the over limit light.=A0 After a couple of re= sets of the breaker, and a couple of shutdowns (turning off battery contact= or), the voltage settled down at 14-14.5.

=A0<= /font>

I=92m not f= ully convinced the contacts were the problem, but I think it likely.=A0 May= be relevant to your situation.

=A0<= /font>

Early this = year I had replaced the voltage regulator after seeing high voltage.=A0 Nex= t time I=92ll replace the pullable breaker or the battery contactor.=

=A0<= /font>

(I bet the = skiing at mammoth was great, and the weather beautiful.)

=A0<= /font>

Al

=A0<= /font>

=A0<= /font>

=A0<= /font>

-----Origina= l Message-----
From: Rot= ary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of David Leonard
Sent: Saturday, December 19= , 2009 5:52 PM
To: Rotar= y motors in aircraft
Subject: [FlyRotary] Real Life No Alternator test

=A0

I have been having an in= termittent and slowly worsening problem with high voltage.=A0 Over most of = the last 30 hrs or so it settled in around 14.6 or 14.7 volts.=A0 But on ye= sterday's flight home from Mammoth I noticed it hovering around 15V and= some of my avionics were acting up, so I decided to do a little alternator= out experiment.

=A0

I turned off the alterna= tor and all unnecessary draw - radio, strobes, Blue Mountain EFIS, electric= AI.=A0 I kept on the engine instrumentation, transponder, music (a most cr= itical item given the beauty of the sunset), audio panel, rocky mountain mi= croencoder, and trio auto pilot (also allowing me to more fully enjoy the f= light). I was showing 8 amps to run the engine bus (coils and injectors).= =A0

=A0

With my 33 amp hour Pana= sonic SLA battery I flew for 45 minutes and=A0200 miles over the Sierras, p= assing dozens of airports,=A0and into the LA basin before it got dark enoug= h that I decided to turn the lights on.=A0 The plan was to turn the alterna= tor back on when the voltage dropped below 11.5 volts but it never dropped = below 11.9V.=A0 It did charge at a brisk 60amps when I turned the alternato= r back on so there couldn't have been too much time left.=A0 Still, tha= t did quite a bit of confidence building regarding the ability to carry on = in the event of an alternator failure.

=A0

I also set a personal re= cord for the most beautiful and clear sunset I have seen while flying.=A0 I= could see San Nicholas Island from over 150 miles away.

=A0

Time to install a spare = alternator.


--
David Leonard=

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.= net

<= br>

--001636ed69dafca5ad047b2c9721--