X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 28 Nov 2013 13:27:05 -0500 Message-ID: X-Original-Return-Path: Received: from qmta08.westchester.pa.mail.comcast.net ([76.96.62.80] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTP id 6617710 for lml@lancaironline.net; Thu, 28 Nov 2013 07:17:03 -0500 Received-SPF: pass receiver=logan.com; client-ip=76.96.62.80; envelope-from=jmorgan1023@comcast.net Received: from omta02.westchester.pa.mail.comcast.net ([76.96.62.19]) by qmta08.westchester.pa.mail.comcast.net with comcast id v06c1m0070QuhwU580GVnk; Thu, 28 Nov 2013 12:16:29 +0000 Received: from [192.168.1.103] ([24.11.157.196]) by omta02.westchester.pa.mail.comcast.net with comcast id v0GU1m00U4EXR5U3N0GVpr; Thu, 28 Nov 2013 12:16:29 +0000 From: Jack Morgan Mime-Version: 1.0 (Apple Message framework v1283) Content-Type: multipart/alternative; boundary="Apple-Mail=_D2C490A6-3F55-4077-AB8C-5453E0C48123" Subject: Re: stuck solemoid X-Original-Date: Thu, 28 Nov 2013 07:16:28 -0500 In-Reply-To: X-Original-To: Lancair Mailing List References: X-Original-Message-Id: <8BBA231C-D2F2-44C0-9D2C-29DEF1F2FF61@comcast.net> X-Mailer: Apple Mail (2.1283) --Apple-Mail=_D2C490A6-3F55-4077-AB8C-5453E0C48123 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 Hi Gordon, The starter solenoid is indeed different than the continuous duty master = solenoid. While they look the same and have a similar contact structure, = the starter solenoid has a much heavier spring to break the contacts = which in turn requires much more coil current (therefore power) to = offset the strong spring. That is why the starter solenoid cannot = sustain continuous operation and overheats. The master solenoid has a = much weaker spring which allows less power to activate it and in turn = allows continuous operation. The weaker spring in the master cannot = overcome the normal welding (called wetting in the relay world) that = results from the high starter current during both contact closure and = break. The master can conduct the starter current fine once closed due = to the large contact structure similar to the starter solenoid. You are not the first, nor will you be the last, to suffer this fate = when the two similar looking relays get mixed up. If you open up your = failed solenoid carefully you will find the movable solenoid armature is = welded to one or both of the side fixed contacts. The tiny weld will be = relatively easy to break and the solenoid will be otherwise fine. The above experience is just one of the many ways to get burned by = improper relay application. Aint this electrical stuff fun. Jack Morgan On Nov 28, 2013, at 6:00 AM, Lancair Mailing List wrote: > From: "Gordon Porter" > Subject: stuck starter solenoid > Date: November 27, 2013 10:50:42 AM EST > To: lml@lancaironline.net >=20 >=20 > Just thought I would throw in a data point here amidst all the relay = talk. > =20 > Two weeks ago I had what turned out to be a stuck starter solenoid. I = had been troubleshooting my noise issue and had done a series of = startups and shutdowns. Four over 20 minutes or so. On the last = shutdown, I momentarily grounded the mags as normal and pulled the = throttle and mixture. Prop kept going=85.thought it was what we used to = call dieseling. Turned off mags=85still running. Fuel off.. still = running. Master off killed it. Master back on turned prop again, and = quickly blew the fuse on my Vertical Power system at the main battery. = I thought I had a problem with the dreaded starter adapter, but that = looked OK. > =20 > I'll save the whole troubleshooting story, but it was indeed the = starter solenoid. 2007 kit, about 90 hours total time. It was a Hersee = solenoid that I got directly from Lancair in the FWF kit for the starter = circuit. The part number was 24144 if my memory is correct (I do have a = pic). I looked it up on their website. It was a continuous duty = solenoid like you would use for a master, and not an intermittent as = needed for the starter circuit. It seems to really make a difference. = Someday I will cut it open to see what it looks like. > =20 > =20 > Gordon >=20 --Apple-Mail=_D2C490A6-3F55-4077-AB8C-5453E0C48123 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=windows-1252 Hi = Gordon,

The starter solenoid is indeed different than = the continuous duty master solenoid. While they look the same and have a = similar contact structure, the starter solenoid has a much heavier = spring to break the contacts which in turn requires much more coil = current (therefore power) to offset the strong spring. That is why the = starter solenoid cannot sustain continuous operation and overheats. The = master solenoid has a much weaker spring which allows less power to = activate it and in turn allows continuous operation. The weaker spring = in the master cannot overcome the normal welding (called wetting in the = relay world) that results from the high starter current during both = contact closure and break. The master can conduct the starter current = fine once closed due to the large contact structure similar to the = starter solenoid.

You are not the first, nor = will you be the last, to suffer this fate when the two similar looking = relays get mixed up. If you open up your failed solenoid carefully you = will find the movable solenoid armature is welded to one or both of the = side fixed contacts. The tiny weld will be relatively easy to break and = the solenoid will be otherwise fine.

The above = experience is just one of the many ways to get burned by improper relay = application. Aint this electrical stuff = fun.

Jack = Morgan

On Nov 28, 2013, at 6:00 AM, = Lancair Mailing List wrote:

From: "Gordon Porter" = <Subject: stuck starter = solenoid
To: 
Just thought I would throw in a data point here amidst all = the relay talk.
 
Two weeks ago I had what turned out to be a stuck starter = solenoid.  I had been troubleshooting my noise issue and had done a = series of startups and shutdowns.  Four over 20 minutes or = so.  On the last shutdown, I momentarily grounded the mags as = normal and pulled the throttle and mixture.  Prop kept = going=85.thought it was what we used to call dieseling.  Turned off = mags=85still running.  Fuel off.. still running.  Master off = killed it.  Master back on turned prop again, and quickly blew the = fuse on my Vertical Power system at the main battery.  I thought I = had a problem with the dreaded starter adapter, but that looked = OK.
 
I'll save the whole = troubleshooting story, but it was indeed the starter solenoid.  = 2007 kit, about 90 hours total time.  It was a Hersee solenoid that = I got directly from Lancair in the FWF kit for the starter = circuit.  The part number was 24144 if my memory is correct (I do = have a pic).  I looked it up on their website.  It was a = continuous duty solenoid like you would use for a master, and not an = intermittent as needed for the starter circuit.  It seems to really = make a difference.  Someday I will cut it open to see what it looks = like.
 
Gordon


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