---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 05/09/24: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:17 AM - Re: Failure Tolerant Architectures (Stuart Hutchison) 2. 04:01 PM - Re: Failure Tolerant Architectures (user9253) 3. 04:57 PM - Re: Re: Failure Tolerant Architectures (Stuart Hutchison) 4. 07:20 PM - Re: Lamar voltage regulator and overvoltage relay (Robert L. Nuckolls, III) 5. 07:24 PM - Re: Failure Tolerant Architectures (user9253) 6. 08:18 PM - Re: Lamar voltage regulator and overvoltage relay (N1921R) ________________________________ Message 1 _____________________________________ Time: 12:17:22 AM PST US From: Stuart Hutchison Subject: Re: AeroElectric-List: Failure Tolerant Architectures A related anecdote Bob On a recent VFR cross-country I had an under current warning on the EFIS during taxi for departure indicating -17A from the battery. Cycling the alternator switch and field CB did nothing. I taxied back in and shut down, then restarted to see if higher RPM would help - the problem disappeared, but wasn=99t normal for our aircraft. We have an almost new 25Ah battery, so I got airborne knowing I could just load shed to get to the next destination 2hrs away if required (with maintenance options at the arrival location) - no problem getting there. On return however, the same problem cropped up, so I load shed the GNS430, autopilot, and electronic ignition in the air and got down to -4A (ie about 5 hours battery endurance with EFIS, backup radio and iPad moving map). After refuel and restart the problem was gone again for most of the last 1hr leg, then reoccured. We suspected the alternator was failing (PlanePower EI70), but discovered the B-lead had almost completely broken through at the alternator terminal (under the silicon boot). Perhaps the crowbar was stepping in and resetting after shut/cool down, what do you think? Kind regards, Stuart > On 7 May 2024, at 4:48=AFAM, Robert L. Nuckolls, III wrote: > > At 12:09 PM 5/3/2024, you wrote: >> >> BoB, Quoting from your post... >> >> "I'm increasingly of the opinion that Z-101 should be the ONLY z-figure in any 'upgrade' to the connection" >> >> While I like the concepts in Z-101 I'm not sold on this being the only idea. > > Of course, there are LOTS of ideas . . . the vast > majority of which have been demonstrated over > the past century in millions of general aviation > light aircraft. I'm aware of none that left the factories > at Beech, Mooney, Cessna or Piper with two > batteries. > > >> There has >> been a number of posts about incorporating a back up battery in its architecture >> which seems counter productive. > > > Not sure what posts you're referring to. > > Yes, some of the z-figures do show how to > add-a-battery . . . some of them decades > old. > > In the OBAM aviation environment we were able > to explore a lot of options with some notion > of improving on a design . . . we learned a lot > over the years . . . including how to > conduct failure modes effects analysis: > > (1) Assuming your battery has been sized and > maintained to meet YOUR battery-only > performance requirements, under what conditions > would you suffer a loss-of-battery emergency > . . . i.e. panel goes dark, engine stops . . .? > > (2) Assume you're cruising along at altitude > watching the ground go by, what kind of battery > failure would produce an event that > got your attention? What would be the nature > of that event? > > > > Bob . . . > > //// > (o o) > ===========o00o=(_)=o00o======= == > < Go ahead, make my day . . . > > < show me where I'm wrong. > > ======================= ========= > > In the interest of creative evolution > for the-best-we-know-how-to-do based > on physics and repeatable experiment. > ________________________________ Message 2 _____________________________________ Time: 04:01:24 PM PST US Subject: AeroElectric-List: Re: Failure Tolerant Architectures From: "user9253" It is unlikely that two things went wrong at the same time. Fix the cable and test fly it. Crowbar circuits usually don't reset themselves. Many of us can not open files with the extension p7s. How about a JPG or PNG picture? -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=513572#513572 ________________________________ Message 3 _____________________________________ Time: 04:57:07 PM PST US From: Stuart Hutchison Subject: Re: AeroElectric-List: Re: Failure Tolerant Architectures For sure Joe. The alternator is likely just fine. B-lead fixed and all good now. However, I=99m interested to know how a damaged B-lead could cause intermittent normal then totally off-line then normal indications if the crowbar doesn=99t reset during shut-down? As an internally regulated system all this would be part of the PlanePower alternator. There was no pic in the first e-mail, I don=99t know what p7s is but here=99s a JPG. Regards, Stuart > On 10 May 2024, at 9:00=AFAM, user9253 wrote: > > > It is unlikely that two things went wrong at the same time. Fix the cable and test fly it. > Crowbar circuits usually don't reset themselves. > Many of us can not open files with the extension p7s. How about a JPG or PNG picture? > > -------- > Joe Gores > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=513572#513572 > > > > > > > > > ________________________________ Message 4 _____________________________________ Time: 07:20:46 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Lamar voltage regulator and overvoltage relay At 08:48 PM 5/5/2024, you wrote: > >Someone on VAF asked and made me curious. > >Aircraft has: >Electrosystems 60A alternator PN ALX8421RS >Lamar voltage regulator B-00267-2 >Lamar overvoltage relay B-00339-1 >Owner suspects regulator is bad. > >I wonder: >What is this overvoltage relay and how is it wired. This is a generic ov sensor that drives a normally closed relay to break the field supply lead in case of an ov event. >Can a Ford regulator VR166 be used in combination with this >overvoltage relay? (Lamar regulator B-00267-2 is only available used >and is expensive.) The VR166 or any of it's dozens of siblings will work fine. We'll have an updated OV module available presently but a simple fused feeder to the relay-style ov management module will suffice nicely. Bob . . . //// (o o) ===========o00o=(_)=o00o======== < Go ahead, make my day . . . > < show me where I'm wrong. > ================================ In the interest of creative evolution for the-best-we-know-how-to-do based on physics and repeatable experiment. ________________________________ Message 5 _____________________________________ Time: 07:24:41 PM PST US Subject: AeroElectric-List: Re: Failure Tolerant Architectures From: "user9253" The vast majority of electrical problems are caused by bad connections, not equipment failure. And bad connections can cause intermittent symptoms as the resistance varies. It is great that you found the problem and fixed it. Good going. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=513574#513574 ________________________________ Message 6 _____________________________________ Time: 08:18:03 PM PST US Subject: AeroElectric-List: Re: Lamar voltage regulator and overvoltage relay From: "N1921R" Thank you Bob Nuckolls. -------- John Bright, RV-6A N1921R, working on FWF. Single battery, alternator on main bus, Monkworkz generator on engine/essential bus. 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