---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 11/22/22: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 0. 11:47 AM - Coming Soon - The List of Contributors - Please Make A Contribution Today! (Matt Dralle) 1. 06:38 AM - Fuse or CB for largish wires into cabin? (rockitdoc) 2. 07:32 AM - Re: Fuse or CB for largish wires into cabin? (user9253) 3. 08:35 AM - Re: Re: Fuse or CB for largish wires into cabin? (Bob Verwey) 4. 01:48 PM - Re: Final Elect. System Review (bcone1381) 5. 03:26 PM - Fusible Links in lieu of ANL protectors (rockitdoc) 6. 04:36 PM - Re: Fusible Links in lieu of ANL protectors (Charlie England) 7. 05:26 PM - Re: Fuse or CB for largish wires into cabin? (user9253) 8. 05:40 PM - Re: Fusible Links in lieu of ANL protectors (Eric Page) 9. 06:46 PM - Re: Fusible Links in lieu of ANL protectors (Robert L. Nuckolls, III) ________________________________ Message 0 _____________________________________ Time: 11:47:37 AM PST US From: Matt Dralle Subject: AeroElectric-List: Coming Soon - The List of Contributors - Please Make A Contribution Today! Each year at the end of the List Fund Raiser, I post a message and link acknowledging everyone that so generously made a Contribution to support the Lists. Its my way of publicly thanking everyone that took a minute to show their appreciation for the Lists. Please take a moment and assure that your name is on that List of Contributors (LOC)! As a number of members have pointed out over the years, the List seems at least as valuable a building / entertainment tool as your typical magazine subscription! Assure that your name is on this year's LOC! Show others that you appreciate the Lists. Making a Contribution to support the Lists is fast and easy using your Credit card or Paypal on the Secure Web Site: https://matronics.com/contribution or by dropping a personal check in the mail to: Matt Dralle / Matronics 581 Jeannie Way Livermore CA 94550 I would like to thank everyone that has so generously made a Contribution thus far in this year's List Fund Raiser! Remember that its YOUR support that keeps these Lists going and improving! Don't forget to include a little comment about how the Lists have helped you! Best regards, Matt Dralle Matronics Email List Administrator ________________________________ Message 1 _____________________________________ Time: 06:38:00 AM PST US Subject: AeroElectric-List: Fuse or CB for largish wires into cabin? From: "rockitdoc" I am designing my power distribution for my RV-14A. Single battery, dual alternators, two Dynon HDX1100's and two Pmags. I am using fuses for everything except Pmags and alternators. I am planning an always hot bus coming off the master contactor before the battery for stuff that would be nice if the contactor fails. Should this wire (10AWG), and for that matter, the wire from the other side of the contactor to the main bus (6AWG), be protected by fuse or CBs since they enter the cabin? Thanks, in advance. Scott -------- RV14A Began 7-23-20 Fuse and tail Completed 2-20-21 Wiring in Process Waiting on Wings, Finish, Engine Read this topic online here: http://forums.matronics.com/viewtopic.php?p=508985#508985 Attachments: http://forums.matronics.com//files/wiring_diagram_v25_592.pdf ________________________________ Message 2 _____________________________________ Time: 07:32:04 AM PST US Subject: AeroElectric-List: Re: Fuse or CB for largish wires into cabin? From: "user9253" The engine is more likely to quit than the battery contactor is to fail. After a forced landing, that always hot #10 wire could make sparks which will ignite leaking gasoline. Having fuses in series is not a good idea. A shorted load could blow both the load fuse and the main fuse. Do not fuse the 6AWG main bus feeder. If the battery contactor fails while flying, you might not even know it because the alternator is supplying electrical power, not the battery. If you are still concerned about the main contactor failing, see the attached circuit. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=508986#508986 Attachments: http://forums.matronics.com//files/contactor_bypass_211.pdf ________________________________ Message 3 _____________________________________ Time: 08:35:44 AM PST US From: Bob Verwey Subject: Re: AeroElectric-List: Re: Fuse or CB for largish wires into cabin? Joe, slight thread drift.. My BD4 is wired with the battery in the back and a fat wire terminates at a firewall stud. The Master Contactor is activated by a switched earth wire 20AWG (with in-line fuse as well) at the panel Master Switch. The concern about unwanted electron flow refers... In the event of a mishap which mashes wires, if the contactor earth wire is shorted out to the airframe by bent metal, then the fat cable gets energised...and being in close proximity to the earth wire, possibly would suffer a breach, and start "welding", the very situation we are trying to avoid. Does one fuse the main cable? ...bearing in mind the horrendous amperage demand of an IO470 starter. On Tue, 22 Nov 2022 at 17:34, user9253 wrote: > > The engine is more likely to quit than the battery contactor is to fail. > After a forced landing, that always hot #10 wire could make sparks which > will ignite leaking gasoline. > Having fuses in series is not a good idea. A shorted load could blow both > the load > fuse and the main fuse. Do not fuse the 6AWG main bus feeder. > If the battery contactor fails while flying, you might not even know it > because the alternator is supplying electrical power, not the battery. > If you are still concerned about the main contactor failing, see the > attached circuit. > > -------- > Joe Gores > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=508986#508986 > > > Attachments: > > http://forums.matronics.com//files/contactor_bypass_211.pdf > > -- Best Regards, Bob Verwey 082 331 2727 ________________________________ Message 4 _____________________________________ Time: 01:48:21 PM PST US Subject: AeroElectric-List: Re: Final Elect. System Review From: "bcone1381" Bob; Battery Condition will be checked every annual with a Lawn Mower destination when 80% capacity is reached. I believe that is an Industry Best Practice. Fusible Link Question. You have a Cartoon titled "How to Fabricate Fusible Links." In block one you say THIS TECHNIQUE IS SUITED FOR 24 AND 22AWG FUSE LINKS ONLY (USE TO PROTECT 20 AND 8AW G WIRES RESEPCTIVELY). CONTACT US FOR SITUATIONS WHERE YOU MAY NEED LARGER FUSE LINKS. What should I know about a 14 AWG fusible Link? NOTE OF GRATITUDE: I cant tell you how much I appreciated your reply. My concerns include fear that I will build in a hidden failure point, or a single point of failure like N811HB. A few days ago I stated reviewing past archive of my questions dating back 5 years to fabricate a list of industry best practices. I'm humbled at your patience and a lot of time with me on this forum. More than I deserve. -------- Brooks Cone Bearhawk Patrol Kit Build Read this topic online here: http://forums.matronics.com/viewtopic.php?p=509072#509072 ________________________________ Message 5 _____________________________________ Time: 03:26:01 PM PST US Subject: AeroElectric-List: Fusible Links in lieu of ANL protectors From: "rockitdoc" I am building an RV14A. I planned on using ANL current limiters for the two alternators (60A PP and 40AB&C), but have since learned of these fusible link thingys. I would prefer not to drill more holes in my firewall to mount the ANLs an fusible links would foot the bill nicely. That is, if they provide the services necessary to protect stuff. If they do, where can one obtain, or how does one fabricate relatively largish fusible links? B&C supplies a 20-24ga link kit which nI have, but what about links much larger? Thanks, in advance, as usual. Scott -------- RV14A Began 7-23-20 Fuse and tail Completed 2-20-21 Wings 99% Finish 90% Engine 99% Wiring in Process Read this topic online here: http://forums.matronics.com/viewtopic.php?p=509074#509074 ________________________________ Message 6 _____________________________________ Time: 04:36:33 PM PST US Subject: Re: AeroElectric-List: Fusible Links in lieu of ANL protectors From: Charlie England On 11/22/2022 5:25 PM, rockitdoc wrote: > > I am building an RV14A. I planned on using ANL current limiters for the two alternators (60A PP and 40AB&C), but have since learned of these fusible link thingys. I would prefer not to drill more holes in my firewall to mount the ANLs an fusible links would foot the bill nicely. That is, if they provide the services necessary to protect stuff. > > If they do, where can one obtain, or how does one fabricate relatively largish fusible links? B&C supplies a 20-24ga link kit which nI have, but what about links much larger? > > Thanks, in advance, as usual. > > Scott > > -------- > RV14A > Began 7-23-20 > Fuse and tail Completed 2-20-21 > Wings 99% > Finish 90% > Engine 99% > Wiring in Process > Historically, they've been pretty common in automotive environments, so they're easy to get. 8 gauge B lead? https://www.google.com/search?q=12+gauge+fusible+link&rlz=1C1CHBF_enUS843US843&oq=12+gauge+fusible+link&aqs=chrome..69i57.5702j0j7&sourceid=chrome&ie=UTF-8 Big 6 gauge B lead? https://www.google.com/search?q=10+gauge+fusible+link&rlz=1C1CHBF_enUS843US843&oq=10+gauge+fusible+link&aqs=chrome..69i57.4102j0j7&sourceid=chrome&ie=UTF-8 You can solder, or use bare copper crimps, & heat-shrink for insulation, or (at least for the smaller lead) you can probably find a Fast-on crimp that's big enough. The purpose-built link wire has its own flame-proof insulation to contain the heat long enough for the link to open. I like them because not only do they reduce the hardware to be mounted, they also greatly reduce the number of terminations/connectors in the circuit. Charlie -- This email has been checked for viruses by Avast antivirus software. www.avast.com ________________________________ Message 7 _____________________________________ Time: 05:26:34 PM PST US Subject: AeroElectric-List: Re: Fuse or CB for largish wires into cabin? From: "user9253" Don't put a fuse in series with the starter motor circuit. A fuse has a certain amount of resistance which will reduce engine cranking speed. As for the main power bus feeder, it is normally not fused, but some builder do install a fuse. If that fuse fails, the panel goes dark. Good workmanship will minimize the danger. Adding extra components complicates the electrical system and increases the danger. If the bus feeder shorts out, the pilot can shut off the battery contactor. Your concern about the battery contactor coil energizing wire accidentally shorting to ground is valid. But I don't know of a safer way to wire it. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=509076#509076 ________________________________ Message 8 _____________________________________ Time: 05:40:45 PM PST US Subject: AeroElectric-List: Re: Fusible Links in lieu of ANL protectors From: "Eric Page" For wrapping your fusible links, search eBay for "silicone fiberglass sleeve". It's similar to fire sleeve, but available in thin-wall versions and small diameters. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=509077#509077 ________________________________ Message 9 _____________________________________ Time: 06:46:04 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Fusible Links in lieu of ANL protectors At 05:25 PM 11/22/2022, you wrote: > > >I am building an RV14A. I planned on using ANL current limiters for >the two alternators (60A PP and 40AB&C), but have since learned of >these fusible link thingys. I would prefer not to drill more holes >in my firewall to mount the ANLs an fusible links would foot the >bill nicely. That is, if they provide the services necessary to protect stuff. Fusible links are the way to go. Just splice them onto the risk-source end of your protected feeder. For the big alternator, I suggest an 8AWG (or larger) feeder with this fusible link. https://tinyurl.com/2md9xov3 For the little alternator build a 10AWG feeder (or larger) with this fusible link. https://tinyurl.com/2mek723r These are just a few options. You can buy BULK fusible link wire but you wind up with a extra wire you will probably never need. Buying automotive pre-fab links is a lot less fussy and nothing to inventory. 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.