---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 12/24/16: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:56 AM - Re: Re: IBBS battery with B and C alternators? (Robert L. Nuckolls, III) 2. 10:33 AM - Re: IBBS battery with B and C alternators? (Jeff Page) 3. 11:05 AM - EFII ignition and injection Z-13/8 (johnbright) 4. 12:53 PM - 2016 List of Contributors (Matt Dralle) ________________________________ Message 1 _____________________________________ Time: 05:56:48 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: IBBS battery with B and C alternators? At 05:24 PM 12/23/2016, you wrote: > >The only contactor failure I've had is when it welded itself shut, >due to a short in the starter motor. It's quite unusual not being >able to turn off the aircraft.. > >On 23Dec2016, at 7:12 PM, user9253 wrote: > > > > > If you're going to that much trouble why not just have two > independently switched contactors? > >There is not much trouble, same number of components either >way. The relay has the advantage of less current, less weight, less >cost, and less space. I am not necessarily recommending this >circuit. Just offering it for others who want redundancy. Contactor failure (or failure of the control wiring/swtich to a contactor is rare. Figure Z-13/8 was designed so that ENDURANCE mode flight was not only possible with the contactor deliberately opened to reduce en route energy demands. Have you done a load analysis of your proposed installation? Have you selected a system architecture? I'm betting that with a little pre-planning and adjustment of architecture, a Plan-B can be identified for every single- failure event but without adding a lot of weight, cost-of-ownership and system complexity. Electrical system failures as root or even contributing cause for a bad day in the cockpit are exceedingly rare. Most bad days in the cockpit arise from poor pilot preparedness for steering around the many inevitable pot-holes in their flying experience. I'll suggest a review of the Z-figures, accompanying notes and supporting narratives in the 'Connection would be useful. Particularly the chapter on system reliability (where 'system' includes prop-to-tailcone environs and all components in between). If you don't have a paper copy of the 'Connection, you can download a .pdf at http://www.aeroelectric.com/Book/AEC_R12A.pdf I've been out of pocket for the last few days . . .had a melt-down of my office computer. Just got a re-build up and running late yesterday. Leaving for Wichita today for Christmas celebrations. Be back on line late Sunday. In the mean time, let's see if we can figure out why Z-13/8 WILL NOT serve to PLAN for any real risks to the enjoyment of your airplane. Lets do failure mode effects analysis to your proposed system with a goal of keeping ANY and ALL single failures from creating an EMERGENCY . . . the goal is to upgrade a component because you're tired of replacing it . . . not because it damned near got you killed. FMEA is the easy, light, most economical way to craft an electrical system and mitigate any worries associated with flying it. Merry Christmas folks! See you in a few days. Bob . . . ________________________________ Message 2 _____________________________________ Time: 10:33:46 AM PST US From: Jeff Page Subject: AeroElectric-List: Re: IBBS battery with B and C alternators? In the event of an emergency landing or fire, it is necessary to turn off both switches. I suggest making that ergonomically easy to do in a single motion. Jeff Page Dream Aircraft Tundra #10 > Time: 08:14:43 AM PST US > Subject: AeroElectric-List: Re: IBBS battery with B and C alternators? > From: "user9253" > > Here is a circuit for those concerned about the master contactor > failing. An automotive > relay is connected in parallel with the master contactor. The relay > is disabled during engine starting to prevent excessive current from flowing > through the relay contacts. Prior to turning on the master > contactor, the relay > can be energized to be sure that it works. The relay must be shut off to > start the engine. After engine start, the relay may be turned back > on. If the > alternator fails, the battery master contactor can be shut off to > conserve energy. > During cruise flight, the relay will only carry battery charging > current. Aircraft > load current will flow directly from the alternator to the main power bus, > not through the relay. > When playing with avionics in the hangar with the engine off, the > relay can be > turned on instead of master contactor. Notice that the arrows on > arc-suppression > diodes point towards positive. > > -------- > Joe Gores > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=464274#464274 > > > Attachments: > > http://forums.matronics.com//files/contactor_bypass_462.pdf > http://forums.matronics.com//files/contactor_bypass_143.jpg ________________________________ Message 3 _____________________________________ Time: 11:05:30 AM PST US Subject: AeroElectric-List: EFII ignition and injection Z-13/8 From: "johnbright" With EFII ignition and injection is Z-13/8 a good choice? I'm not sure the current draw of one pump, one ignition, and injectors; could be too much for the 8 amp alternator. Is Z-13/8 suitable for a 20 amp backup alternator or would that lead one to Z-12? I know I need to do a load analysis. Thanks for the LA-IFP accident report. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=464299#464299 ________________________________ Message 4 _____________________________________ Time: 12:53:39 PM PST US From: Matt Dralle Subject: AeroElectric-List: 2016 List of Contributors Dear Listers, The 2016 Matronics Email List and Forum Fund Raiser officially ended a couple of weeks ago and it's time that I published this year's List of Contributors. It is the people on this list that directly make these Email Lists and Forums possible! Their generous Contributions keep the servers and Internet connection up and running! You can still show your support this year and pick up a great gift at the same time. The Contribution Web Site is fast, easy, and secure: http://www.matronics.com/contribution Or, by dropping a personal check in the mail to: Matt Dralle / Matronics 581 Jeannie Way Livermore CA 94550 I also want to thank Andy, Bob, George, and Jon for their generous support through the supply of many great gifts this year!! These guys have some excellent products and I encourage you to visit their respective web sites: Andy Gold - The Builder's Bookstore - http://www.buildersbooks.com Bob Nucklolls - AeroElectric - http://www.aeroelectric.com George Race - Race Consulting - http://www.mrrace.com Jon Croke - HomebuiltHELP - http://www.homebuilthelp.com And finally, I'm proud to present The 2016 Fund Raiser List of Contributors: http://www.matronics.com/loc/2016.html Thank you again to everyone that made a Contribution this year!! 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