---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 08/19/12: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:18 AM - Re: AeroElectric-List Digest: 9 Msgs - 08/18/12 (James Meade) 2. 07:04 AM - Re: snorkel for alternator cooling (Robert L. Nuckolls, III) 3. 08:48 AM - Re: snorkel for alternator cooling (jonlaury) 4. 09:31 AM - extra cooling for alternator (Janet Amtmann) ________________________________ Message 1 _____________________________________ Time: 06:18:05 AM PST US Subject: AeroElectric-List: Re: AeroElectric-List Digest: 9 Msgs - 08/18/12 From: "James Meade" From Wikipedia. See the reference tables to confirm the entry. "The AWG tables are for a single, solid, round conductor. The AWG of a stranded wire is determined by the total cross-sectional area of the conductor, which determines its current-carrying capacity and electrical resistance. Because there are also small gaps between the strands, a stranded wire will always have a slightly larger overall diameter than a solid wire with the same AWG." http://en.wikipedia.org/wiki/American_wire_gauge ________________________________ Message 2 _____________________________________ Time: 07:04:49 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: snorkel for alternator cooling At 11:58 AM 8/18/2012, you wrote: Thanks to everyone who replied. Bob N. Thanks for your explanation. No, nothing special about my alternator installation, N-D in the standard position for a Lyc. I was only concerned because someone who had done the cooling duct on an RV6 was concerned because I had none. I thought better safe than sorry. Added cooling doesn't hurt anything . . . usually. We added a scupper on the fuselage of the single engine airplanes at Cessna way back when to bring outside ram air into the radio stack. I recall a flurry of activity over that installation when a customer reported damage to radios due to ingress of rain! On the other hand, 'things' added to any project has a cost of ownership in $time$ to install and maintain that thing . . . and loss of weight and volume resources for having installed it. Alternator cooling has been a hot topic of discussion on the various OBAM aviation forums since I've been participating. Folks have attributed many failures of alternators to 'a lack of cooling' but without supporting evidence. I have yet to see any MEASUREMENTS of performance that suggests a reduction of risk for cost or safety for having added cooling to the alternator. I'm not suggesting that you should not add the cooling . . . I have no basis for asserting ANY justification one way or the other. Intuitively, I have observed what happens under the hood of my car for an alternator that gets heavily loaded in the worst of local temperature and airflow conditions yet it has hummed along nicely for 11+ years and 170,000 miles . . . without a forced air cooling feature. The scat tube is light, the time expended in the grand scheme of things is small. But it would be really interesting to know if the effort has any beneficial effect. Bob . . . ________________________________ Message 3 _____________________________________ Time: 08:48:56 AM PST US Subject: AeroElectric-List: Re: snorkel for alternator cooling From: "jonlaury" nuckolls.bob(at)aeroelect wrote: > At 11:58 AM 8/18/2012, you wrote: > ... snip > > The scat tube is light, the time expended in > the grand scheme of things is small. But it > would be really interesting to know if the effort > has any beneficial effect. > > > Bob . . . The cooling shroud that I built and the scat tube (7") are a few ounces and part of the "mission" of this project has been to have fun.Designing and fabbing this thing qualifies. Knowing that I was going to build an airplane that was dependent on electrowhizzies to keep air underneath the wheels, I asked an old-school alternator/starter repair shop guy (the kind of place with alternators up to the rafters and huge, antediluvian black machines peppered with large analog meters and cats sleeping on top) for the best way to keep alternators alive and he said to just keep the diode plate(s) cool. So that is what I did. For both alternators [Wink] John Read this topic online here: http://forums.matronics.com/viewtopic.php?p=381243#381243 ________________________________ Message 4 _____________________________________ Time: 09:31:03 AM PST US Subject: AeroElectric-List: extra cooling for alternator From: Janet Amtmann Many thanks for all who chimed in on my concern about extra cooling for a stock alternator. Bob's explanation sound good, and it saves me some work in not installing something that might or might not have any beneficial effect. J=FCrgen Amtmann RV-6 N188LF Do not archive ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.