---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 04/26/23: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:59 AM - Re: Which Oil Pressure Switch? (Robert L. Nuckolls, III) 2. 10:10 AM - Re: Wiring Looms (Robert L. Nuckolls, III) 3. 10:28 AM - Re: Wiring Looms (Robert L. Nuckolls, III) 4. 04:54 PM - Re: Which Oil Pressure Switch? (Mudfly) 5. 06:27 PM - Re: Re: Which Oil Pressure Switch? (A RICHARD GOLDMAN) ________________________________ Message 1 _____________________________________ Time: 09:59:20 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Which Oil Pressure Switch? [quote="nuckolls.bob(at)aeroelect"]At 07:56 AM 4/21/2023, you wrote: Shawn, Could you set this hourmeter up on the bench and measure the current draw on the enable pin in the pull-up configuration? I think I have a simple solution using p-lead signal from a mag to drive the enable pin but having that current value would facilitate optimization of the components. Bob . . . //// (o o) ===========o00o=(_)=o00o======== < Go ahead, make my day . . . > < show me where I'm wrong. > ================================ In the interest of creative evolution of the-best-we-know-how-to-do based on physics and good practice. ________________________________ Message 2 _____________________________________ Time: 10:10:19 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Wiring Looms At 05:48 AM 4/25/2023, you wrote: > > >Have over 40yrs experience in automotive and now swapped to >aviation; what an absolute joy!! > >Regarding wiring looms.. what spec wire are people using in aircraft >looms, and what is being used as the outer protective sheathing? Is >it a specific shrink wrap fire retardant material? > >Thanks in advance. Designers of TC aircraft go out of their way to avoid a necessity for mechanically shielding wire bundles. When external covers are found on the drawings, there's a special risk for mechanical damage to the bundle . . . wheel wells, exposure to foot traffic, etc. There are lots of things in airplanes that would suffer operational compromise if they came into antagonistic contact with foreign bodies. Bus bars, control cables . . . and yeah, wire bundles. First rule of thumb is to conduct the failure modes effects analysis to identify risk and then eliminate it. If not possible/practical, then add 'shielding'. Shielding is rarely found to be useful. Bob . . . //// (o o) ===========o00o=(_)=o00o======== < Go ahead, make my day . . . > < show me where I'm wrong. > ================================ In the interest of creative evolution of the-best-we-know-how-to-do based on physics and good practice. ________________________________ Message 3 _____________________________________ Time: 10:28:17 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Wiring Looms >Under the cowl you can use Mil Spec 22759/11, which has silver, >rather than solder coating the copper strands. The insulation is >Teflon, rather than Tefzel. This wire withstands higher heat [200 C] >than 22759/16. The Teflon insulation is softer, so it can be bent >into tighter radii. Many avionics shops will use the /11 wire behind >the instrument panel, to allow tighter loops in the harness. One >caveat with the /11 wire, don't secure it to tightly or use Nylon >wire ties, as this can saw through the soft Teflon insulation over >time. FYI, I have found it easier to get the /11 wire in colors. Teflon over silver plated wire is not recommended for general airframe wiring or appliance fabrication. I don't think our wire bundle shops even had Teflon in inventory . . . Had a conversation about Teflon with with Greg Richter of BlueMountain fame starting on page 38 of this document: https://tinyurl.com/2tbearkn Bob . . . //// (o o) ===========o00o=(_)=o00o======== < Go ahead, make my day . . . > < show me where I'm wrong. > ================================ In the interest of creative evolution of the-best-we-know-how-to-do based on physics and good practice. ________________________________ Message 4 _____________________________________ Time: 04:54:46 PM PST US Subject: AeroElectric-List: Re: Which Oil Pressure Switch? From: "Mudfly" Will do Bob. I'll try and get that set up tomorrow and post what I find. Thanks. Shawn Shawn, Could you set this hourmeter up on the bench and measure the current draw on the enable pin in the pull-up configuration? I think I have a simple solution using p-lead signal from a mag to drive the enable pin but having that current value would facilitate optimization of the components. Bob . . . //// (o o) ===========o00o=(_)=o00o========= < show me where I'm wrong. > ================================ In the interest of creative evolution of the-best-we-know-how-to-do based on physics and good practice.[/quote] Read this topic online here: http://forums.matronics.com/viewtopic.php?p=510710#510710 ________________________________ Message 5 _____________________________________ Time: 06:27:41 PM PST US From: A RICHARD GOLDMAN Subject: Re: AeroElectric-List: Re: Which Oil Pressure Switch? Whatever you choose for a transducer for any liquid pressure, make sure you install a restrictor in line to prevent major fluid loss in case of physical sensor leakage or breakage. Sent from my iPhone > On Apr 26, 2023, at 6:54 PM, Mudfly wrote: > > > Will do Bob. I'll try and get that set up tomorrow and post what I find. > Thanks. > Shawn > > > > Shawn, > > Could you set this hourmeter up on the bench > and measure the current draw on the enable > pin in the pull-up configuration? I think > I have a simple solution using p-lead > signal from a mag to drive the enable pin > but having that current value would facilitate > optimization of the components. > > > Bob . . . > > //// > (o o) > ===========o00o=(_)=o00o========= > > < show me where I'm wrong. > > ================================ > > In the interest of creative evolution > of the-best-we-know-how-to-do based > on physics and good practice.[/quote] > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=510710#510710 > > > > > > > > > ------------------------------------------------------------------------------------- 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.