---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 05/04/18: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:40 AM - Re: Re: Z-13/8 Question (Ken Ryan) 2. 09:47 AM - Re: Velcro Ties (FLYaDIVE) 3. 10:02 AM - Re: Z 16 OVP fuselink question (William Daniell) 4. 10:51 AM - Re: Velcro Ties (Ernest Christley) 5. 02:08 PM - Re: Z 16 OVP fuselink question (user9253) 6. 02:19 PM - Re: Z 16 OVP fuselink question (Robert L. Nuckolls, III) 7. 04:35 PM - Re: Z 16 OVP fuselink question (CORRECTION) (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 09:40:30 AM PST US From: Ken Ryan Subject: Re: AeroElectric-List: Re: Z-13/8 Question Bob, >From my limited experience, I see no demonstrable benefit to working with wire as fine as 24AWG. Certainly the weight is a non-issue. 24AWG is downright dainty compared to 20AWG. I think it is criminal that Ray Allen uses such fine wire in its servo pigtails. To me, using such fine wire is just asking for trouble. On Sat, Apr 28, 2018 at 11:43 AM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 12:26 PM 4/28/2018, you wrote: > > Thanks Bob. That clears some things up for me. You have not commented on > using 20AWG with a 24AWG fuselink. I'm sure at some point the mechanical > properties of the wire become an issue. Is 24AWG too small to be messing > with for a fuselink? > > > Actually, no . . . > > We used a lot of 24AWG in the airframe wiring > on Premier . . . lots of grumbling at the outset > but I think if proved to be pretty much a non > issue. When crimping 24AWG into the red pidg > terminals, I do double the strip length and > fold the strands back to double the copper > in the crimp . . . and i'm not sure that > offers demonstrable benefit. > > Play around with it on the bench and see > what YOU think . . . > > Bob . . . > ________________________________ Message 2 _____________________________________ Time: 09:47:57 AM PST US From: FLYaDIVE Subject: Re: AeroElectric-List: Velcro Ties Because I work on a lot of certified aircraft and on them it is not permitted. Your logic is good... And another reason why to replace the Velcro with ty-wraps. The Velcro is REPLACEABLE, so I can use it on other planes without buying more and Velcro cost more than a handful of ty-wraps. Barry On Thu, May 3, 2018 at 10:11 PM, Ernest Christley wrote: > Why do you replace the velcro, Barry? I've left it on, and after 6 > months, if you can't find the end of the strip, it is VERY hard to get off. > > > On Thursday, May 3, 2018 3:23 PM, FLYaDIVE wrote: > > > Art: > > I use Velcro all the time. GREAT for when you are figuring out where and > how to run wires. Then AFTER all is good, I replace them with Black > Ty-Wraps. Well, not all black ty-wraps. I use RED on power lines green on > signal lines and yellow on audio lines. When ever I can... Sometimes > bundles just don't cooperate. > > Barry > > On Wed, May 2, 2018 at 10:02 PM, Art Zemon wrote: > > Folks, > > Do you have any thoughts about using Velcro ties, or generic hook 'n' loop > straps, for dressing wires behind the instrument panel? It's seeming like a > good idea to me, especially in a plane where the panel is not "done." But > maybe my ol' brain is simply addled with exhaustion. > > Thanks, > -- Art Z. > > -- > https://CheerfulCurmudgeon. com/ > > *"If I am not for myself, who is for me? And if I am only for myself, what > am I? And if not now, when?" Hillel* > > ________________________________ Message 3 _____________________________________ Time: 10:02:54 AM PST US From: William Daniell Subject: Re: AeroElectric-List: Z 16 OVP fuselink question Joe and Bob, Thanks so much...as usual a real education. I had no idea that a 22 AWG fuselink is equivalent to a 30-40AMP fuse. Intuitively I thought it was much less. Much appreciated. So if a 22AWG wire is normally "rated" to 5A which means 10degC (Ch8-8) current rise presumably therefore needs 40A to get to melting point. By the same token the 16AWG fuselink at the starter contactor (from the alternator) and from the battery contactor to the buss performs in a similar way. If this is correct the 16AWG fuselink rated at 12.5A for 10 degC current rise will melt at something like 100A. Whereas the 12AWG wire it's protecting will melt at something like 150 . Is this correct? Will William Daniell LONGPORT +57 310 295 0744 On Thu, May 3, 2018 at 8:24 PM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 06:51 AM 5/3/2018, you wrote: > > The positive wire from the buss to master (and OVP module) to ALT relay i s > protected by 22AWG fuselink. > > Can I use an ATC fuse instead? > > I have reformed and simplified my electrical system based on AEC.=C3=82 I now > have a fuse buss instead of breakers etc.=C3=82 I have a slot spare and to use > an ATC fuse would be simpler. > > > A piece of 22AWG wire has a hard fault > fusing characteristic on a par with a > 40-50 at MaxiFuse. You could use a > MaxiFuse but it's bulkier than the > fusible link. > > > Bob . . . > ________________________________ Message 4 _____________________________________ Time: 10:51:08 AM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Velcro Ties :-) That last one was the best.=C2- Don't want to be handing out that expensi ve velcro to everybody that wanders in.=C2- I only have the one plane to work on...for now, so it makes a good place to store my spares.=C2- :-) On Friday, May 4, 2018 12:48 PM, FLYaDIVE wrote: Because I work on a lot of certified aircraft and on them it is not permit ted. Your logic is good...=C2- And another reason why to replace the Velcro wi th ty-wraps. The Velcro is REPLACEABLE, so I can use it on other planes without buying m ore and Velcro cost more than a handful of ty-wraps. Barry On Thu, May 3, 2018 at 10:11 PM, Ernest Christley wrot e: Why do you replace the velcro, Barry?=C2- I've left it on, and after 6 mo nths, if you can't find the end of the strip, it is VERY hard to get off. On Thursday, May 3, 2018 3:23 PM, FLYaDIVE wrote: Art: I use Velcro all the time. GREAT for when you are figuring out where and ho w to run wires.=C2- Then AFTER all is good, I replace them with Black Ty- Wraps.=C2- Well, not all black ty-wraps.=C2- I use RED on power lines g reen on signal lines and yellow on audio lines.=C2- When ever I can...=C2 - Sometimes bundles just don't cooperate. Barry On Wed, May 2, 2018 at 10:02 PM, Art Zemon wrote: Folks, Do you have any thoughts about using Velcro ties, or generic hook 'n' loop straps, for dressing wires behind the instrument panel? It's seeming like a good idea to me, especially in a plane where the panel is not "done." But maybe my ol' brain is simply addled with exhaustion. Thanks,=C2- =C2- -- Art Z. -- https://CheerfulCurmudgeon. com/ "If I am not for myself, who is for me? And if I am only for myself, what a m I? And if not now, when?" Hillel ________________________________ Message 5 _____________________________________ Time: 02:08:58 PM PST US Subject: AeroElectric-List: Re: Z 16 OVP fuselink question From: "user9253" See the website below for a pdf listing the fusing (melting) current of wires. It is a lot higher than one might expect. The choice of wire size has more to do with voltage drop and insulation properties than the ampacity of the wire. http://www.hsmwire.com/New%20PDFs/Fusing_Currents_Melting_Temperature_Copper_Aluminum_Magnet_Wire.pdf -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=479856#479856 ________________________________ Message 6 _____________________________________ Time: 02:19:36 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Z 16 OVP fuselink question At 12:01 PM 5/4/2018, you wrote: >Joe and Bob, > >Thanks so much...as usual a real education.=C2 =C2 >I had no idea that a 22 AWG fuselink is >equivalent to a 30-40AMP fuse.=C2 =C2 Intuitively I >thought it was much less.=C2 =C2 Much appreciated. > >So if a 22AWG wire is normally "rated" to 5A >which means 10degC (Ch8-8) current rise >presumably therefore needs 40A to get to melting point.=C2 Exactly . . . see https://goo.gl/zye61w Circuit protection is about keeping insulation temperatures comfortably below maximum rated operating vales. Wire size is all about maintaining distribution voltage drops below acceptable levels based on system design goals. 5% is the max-drop rule of thumb although other values may be adopted by program managers. Wire sizing tends to be very conservative . . . unless you are as weight-sensitive as a moon mission or Voyager flight, the design rules will keep wires pretty cool. >By the same token the 16AWG fuselink at the >starter contactor (from the alternator) and from >the battery contactor to the buss performs in a >similar way. If this is correct the 16AWG >fuselink rated at 12.5A for 10 degC current rise >will melt at something like 100A. Whereas the >12AWG wire it's protecting will melt at something like 150. Fusible links in vehicles are expected to protect major feeders of a distribution system against hard faults . . . generally experienced only during major disassembly of the vehicle. By hard fault, were talking many times hundreds to thousands of amps supplied by a battery . . . not the soft fault precipitated by a failing appliance. https://goo.gl/QEBeZs >Is this correct? Generally . . . When we use plain-vanilla wire as a fusible link in the OBAM aircraft world, it's a good idea to use the silicone/fiberglas sleeving over it to limit the propagation of heat damage during a fusing event. In the ground transportation industries, fusible links are fabricated from wire having friendlier outcomes during the fusing event. Hypalon insulation (A Dupont product that targeted electric locomotives in mines) is used on many fusible link replacement assemblies available at your local car parts stores . . . or in bulk wire on places like eBay. https://goo.gl/RH2eEY The material selected for a fusible link has little to do the loads presented by downstream appliances. The wire in fusible link is EXPECTED to burn . . . at many degrees above the insulation rating. Selection of material is about reduction of risk in the rare but catastrophic event. Bob . . . ________________________________ Message 7 _____________________________________ Time: 04:35:57 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Z 16 OVP fuselink question (CORRECTION) The redirection link didn't capture the whole page . . . here's a 'fix' . . . Fusible links in vehicles are expected to protect major feeders of a distribution system against hard faults . . . generally experienced only during major disassembly of the vehicle. By hard fault, were talking many times hundreds to thousands of amps supplied by a battery . . . not the soft fault precipitated by a failing appliance. https://goo.gl/up9oNB Bob . . . 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