---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 07/08/22: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:05 PM - Re: Re: Thermocouples: grounded or ungrounded (Paul Eckenroth) ________________________________ Message 1 _____________________________________ Time: 02:05:16 PM PST US From: Paul Eckenroth Subject: Re: AeroElectric-List: Re: Thermocouples: grounded or ungrounded [image: IMG-1229.jpg] Bob I agree with what you are saying concerning the ideal method of monitoring the coils. However I need to work with what I have and I don't think I can monitor 12 individual coils with the tools at my disposal. I do plan on using your idea of the rotary switch and I appreciate the schematic. I thought all might be interested in a picture of the stator after removal. The one coil suffered catastrophic damage with the phenolic spacer completely destroyed by the heat. I have machined the case to allow more ventilation and will add two blast tubes directly at the coils. And hope for the best. Paul I did check with GRT and their EIS/ EFIS cannot read thermocouples except through the 4 or 6 EGT and CHT inputs. On Thu, Jul 7, 2022 at 3:22 PM Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > The most important temperature readings will be of the stator. > > > yeaaahhh . . . sort of. Temperature numbers of the stator > stack adjacent to mounting bolts will be greatly > influenced by heat transfer to the crankcase. > > We know that the stator failures are generally limited > to one pole. How do the wires look on remaining poles? > To precipitate this 'isolated' failure suggests a thermal > runaway event where the resistance of copper rises with > temperature which in turn, increases energy dissipated in > the wires. I.e. a positive feedback for temperature > excursion. > > To catch a pending failure suggest a need to monitor > each winding . . . unless field experience shows that > failures are concentrated. > > In any case, other temperatures around the system's > components may be interesting data but I'm skeptical > as to their ability to flag impending failure any > one coil. > > Bob . . . > > Un impeachable logic: George Carlin asked, "If black boxes > survive crashes, why don't they make the whole airplane > out of that stuff?" > ------------------------------------------------------------------------------------- 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.