rob(at)robcaldwell.net
Guest
|
 Posted: Sun Aug 18, 2019 4:52 am Post subject: AeroElectric-List Digest: 5 Msgs - 08/17/19 |
 |
|
Sorry to disturb the flow of this thread…. However, I have tried repeatedly to unsubscribe from this list, followed the instructions to the letter, even contacted the admin with no success. If anyone can give me a hand I would be greatly appreciative.
Please unsubscribe: rob(at)robcaldwell.net (rob(at)robcaldwell.net)
Thank you! | Quote: | On Aug 18, 2019, at 2:30 AM, AeroElectric-List Digest Server <aeroelectric-list(at)matronics.com (aeroelectric-list(at)matronics.com)> wrote:
* Online Versions of Today's List Digest Archive Today's complete AeroElectric-List Digest can also be found in either of the two Web Links listed below. The .html file includes the Digest formatted in HTML for viewing with a web browser and features Hyperlinked Indexes and Message Navigation. The .txt file includes the plain ASCII version of the AeroElectric-List Digest and can be viewed with a generic text editor such as Notepad or with a web browser. HTML Version: fransew(at)gmail.com (fransew(at)gmail.com)>The purpose of a fuse in the alternator output circuit is to protect the batteryfrom short circuits. Alternator output is self current limiting. The quantityof electrons flowing is limited by the ability of the magnets to push them. There is no inductive voltage spike when a load is removed from the alternator.The voltage will go up because the electrons being pushed by magnets haveno where to go. But the voltage is not induced by a collapsing magnetic field. Alternator windings can fry due to overheating caused by inadequate cooling ordue to prolonged high current output. Electrically speaking, there are twoseparate alternators. But both are contained in one physical enclosure. Operatingboth alternators simultaneously at full output generates lots of heat whichcould fry windings. The solution is to redesign the alternator with largerwires and/or better cooling. Or limit the load. Or limit the total outputcurrent by operating only one alternator at a time.--------Joe GoresRead this topic online here:http://forums.matronics.com/viewtopic.php?p=490918#490918________________________________ Message 2 _____________________________________Time: 06:34:37 AM PST USSubject: Bent EGT Probe Acceptable?From: "jdubner" <jdubner(at)yahoo.com>Would it be permissible to bend an EGT probe as in the attached image and stillreceive good service from it? This is for avoiding interference with the cowland other obstructions in a Long-EZ installation.Thanks,Joe--------RV-8AIndependence, ORRead this topic online here:http://forums.matronics.com/viewtopic.php?p=490919#490919Attachments: http://forums.matronics.com//files/bent_egt_probe_example_543.jpg________________________________ Message 3 _____________________________________Time: 09:02:28 AM PST USSubject: Re: Revmaster PM alternatorsFrom: "dj_theis" <djtheis58(at)gmail.com>Thanks Joe,The purpose of a fuse in the alternator output circuit is to protect the batteryfrom short circuits. Alternator output is self current limiting.I appreciate your feedback. The short circuit protection meant to protect thebattery was not something I had considered as the design intent. I Understandthe fixed current model of the PM alternator so what a damaged winding suggestsis a weak or less than robust design, as you imply. If you noticed, the ignition circuits are part of the same flywheel assembly andin neither of these cases did the ignition fail. This is evidence to me thatthe self destructive heat generated by a stator winding was not high enoughto propagate the damage beyond the source of the heat (the physical relationshipis as the drawing shows, the ignition coils separate the alternator windings).Now that I think of it, the 450 hour plane did have a previous incident where theignition coil failed and the smell he sensed when the alternator failed ledhim to expect one of the ignition coils had failed again. Note, with none ofthese failures did the engine stop running. The ignition coils are redundant.One feeds the upper ignition and one feeds the lower.I doubt I can obtain any forensic data on the failed systems but I will give ita shot and see what might be learned. My goal is to modify (improve) my engine charging system to avoid any of thesefailures.Thanks again for your feedback Joe. It helps a lot.Dan TheisSonex 1362R |
--------Scratch building Sonex #1362Read this topic online here:http://forums.matronics.com/viewtopic.php?p=490920#490920________________________________ Message 4 _____________________________________Time: 06:39:43 PM PST USFrom: Art Zemon <art(at)zemon.name>Subject: Re: Flaky EGT ProbeBob,The Lycoming operating manual says:LEANING WITH MANUAL MIXTURE CONTROL. (Economy cruise, 75% power or less, | Quote: | | without flowmeter or EGT gauge.)<snip>Fuel Injected Engines.(1) Slowly move mixture control from =9CFull Rich=9D position |
toward lean | Quote: | | position.(2) Continue leaning until slight loss of power is noted (loss of powermay or may not be accompanied by roughness.(3) Enrich until engine runs smoothly and power is regained. |
I tried this method and compared the results with using the EGT (also perLycoming's operating manual). I got the same fuel flow both ways.I learned the manual method in airplanes that lacked an EGT probe on eachcylinder. It's quick and doesn't require me to interrupt my scan. -- Art Z.On Fri, Aug 16, 2019 at 1:18 AM Bob Verwey <bob.verwey(at)gmail.com> wrote: | Quote: | Hi ArtSo how is it that you dont use your EGT? To me it is a prized tool in theengine management arsenal!On Fri, 16 Aug 2019 at 05:03, Art Zemon <art(at)zemon.name> wrote: | Quote: | | Folks,One of my four EGT probes is flaky. Sometimes it works. Most of the timeit reads zero (too low to register). I don't actually use the EGT foranything so I'm not very excited about spending money to fix it. But itannoys me to see three nice green bars and one black space where thereshould be a green bar.Are these things repairable? -- Art Z.--https://CheerfulCurmudgeon.com/*Love the stranger for you yourselves were strangers in Egypt. *Deut.10:19 |
--Best...Bob Verwey082 331 2727 |
-- https://CheerfulCurmudgeon.com/*Love the stranger for you yourselves were strangers in Egypt. *Deut. 10:19________________________________ Message 5 _____________________________________Time: 06:45:09 PM PST USFrom: Art Zemon <art(at)zemon.name>Subject: Re: Re: Dual Alternator "Failure" - SOLVEDYou're so right, Joe.And for anyone interested, here is the full write-up on my blog:https://cheerfulcurmudgeon.com/2019/08/17/dual-alternator-failure/Cheers, -- Art Z.On Wed, Aug 14, 2019 at 8:07 PM user9253 <fransew(at)gmail.com> wrote: | Quote: | | The above situation reinforces the recommendation to have a separate fusefor each and every load, no matter how small or insignificant. Fuse areinexpensive. |
-- https://CheerfulCurmudgeon.com/*Love the stranger for you yourselves were strangers in Egypt. *Deut. 10:19
[/quote]
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
