---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 07/17/18: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:26 AM - Re: B&C switches (user9253) 2. 08:17 AM - Fw: Re: Question for Bob (Rocketman1988) 3. 08:23 AM - Re: Fw: Re: Question for Bob (John Tipton) 4. 09:20 AM - Re: Re: B&C switches (Ken Ryan) 5. 09:45 AM - Re: Re: B&C switches (Ken Ryan) 6. 10:02 AM - Fw: Re: Question for Bob (user9253) 7. 10:39 AM - Re: Re: B&C switches (Robert L. Nuckolls, III) 8. 10:46 AM - Electronic Bus Manager Versus Fuses & Breakers (user9253) 9. 11:48 AM - Failure Mode Effects Analysis (Robert L. Nuckolls, III) 10. 12:08 PM - Fw: Re: Question for Bob (Rocketman1988) 11. 02:24 PM - Re: Fw: Re: Question for Bob (Robert L. Nuckolls, III) 12. 02:25 PM - Cost effective technology (Robert L. Nuckolls, III) 13. 03:16 PM - Re: Re: B&C switches (Charlie England) 14. 03:23 PM - Re: Re: B&C switches (FLYaDIVE) ________________________________ Message 1 _____________________________________ Time: 05:26:53 AM PST US Subject: AeroElectric-List: Re: B&C switches From: "user9253" Nothing lasts forever, including the newfangled electronic bus managers. When something goes wrong, the whole box must be sent back to the manufacturer for repair, if they are still in business. Compare that to conventional wiring when a fuse blows. Yes, electrical knowledge is required to figure out why the fuse blew. But the aircraft is still flyable without that one circuit, which any mechanic can troubleshoot. Fuses are just as easy to install as the electronic box and cost a whole lot less. Being able to view the current draw of each circuit on the EFIS screen is a nice feature. But wouldn't it be better to be looking out the windows and to do troubleshooting when on the ground? -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=481691#481691 ________________________________ Message 2 _____________________________________ Time: 08:17:46 AM PST US Subject: AeroElectric-List: Fwd: Re: Question for Bob From: "Rocketman1988" Very true. You posted a reply in another thread that stated battery contactor failures in flight are exceedingly rare. Hypothetically, you could put a battery contactor in the feed line to a forward buss. This contactor would be checked prior to every flight, as the engine could not be started if there was a failure, and the ability to isolate the battery is retained. Given that there would be two separate feeders to that buss, the likelihood of both contactors failing simultaneously would be quite small, leaving the buss powered in the event of a single failure. Thoughts? Read this topic online here: http://forums.matronics.com/viewtopic.php?p=481699#481699 ________________________________ Message 3 _____________________________________ Time: 08:23:51 AM PST US Subject: Re: AeroElectric-List: Fwd: Re: Question for Bob From: John Tipton It's a pity that this topic didn't have a proper Thread/Subject line, for future reference John Sent from my iPad ----x--O--x---- > On 17 Jul 2018, at 4:17 pm, Rocketman1988 wrote: > > > Very true. > > You posted a reply in another thread that stated battery contactor failures in flight are exceedingly rare. Hypothetically, you could put a battery contactor in the feed line to a forward buss. This contactor would be checked prior to every flight, as the engine could not be started if there was a failure, and the ability to isolate the battery is retained. Given that there would be two separate feeders to that buss, the likelihood of both contactors failing simultaneously would be quite small, leaving the buss powered in the event of a single failure. > > Thoughts? > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=481699#481699 > > > > > > > > > ________________________________ Message 4 _____________________________________ Time: 09:20:28 AM PST US From: Ken Ryan Subject: Re: AeroElectric-List: Re: B&C switches Bob, I would love to hear actual specifics on precisely what aspects of the EFII bus manager make it unsafe (or less safe) than your legacy drawings, and more importantly, how the legacy drawings overcome the deficits of the Bus Manager. Ken Ryan On Mon, Jul 16, 2018 at 7:13 PM Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 08:54 PM 7/16/2018, you wrote: > > den_beaulieu@yahoo.com> > > Thanks Bob, I get nervous when you get "mystified"... my setup is a dual > battery, with single PMA alternator The alternator runs thru a 40A ANL > then to a common terminal with Batt #1 to the Main bus relay, and the #2 > battery runs to the Essential (endurance) bus relay. The EarthX batteries > have onboard battery management (BMS) for battery "issues", and I have the > B&C OVP module for the alternator, along with cockpit disconnect switch. I > went with the EFII Bus Manager as a way to help with my system wiring > during my design phase. Pros and Cons are always ready to be heard by > me...only way I can consider improvements for the next time or as needed. > I did go ahead and start wiring for the hydraulic pump with items from the > "care" package you sent. Decided to tap power directly from the #1 > battery, thru the MANL to the relays which are all located on the engine > firewall forward. About a 8" run from the positive terminal to the MANL, > and 6" run to the relays, and plenty of convenient grounding tabs! I've > attached a pic for comments. Thanks for everyone's interest and > insight...very much appreciated! Dave > > > I understand . . . and no doubt the EFII > gizmo performs as advertised. But you've already > experienced a design conundrum with where to tie > your hydraulic pump feeder to the system. > > Products like the ECII, EXP-Bus, etc all perform > as advertised in the designer's airplane and > probably most of his/her customers. But the problem > you're wrestling wasn't conceived by the designer > of the whiz-bang-box . . . further, the design > chooses to march to the beat of a different drum > when it comes to FMEA and legacy design goals > for aircraft. > > This is why there are so many variations on a > theme in the z-figures. For TC single engine aircraft, > the wirebook for a C150 wasn't materially different > than for a C210. Even today, that line of aircraft > use a lot of common hardware. Cessna has their own > whiz-bang box > > [image: Emacs!] > > Even includes the ground power connector! > > The difference between this whiz-bang-box and > the EFII is that the box was designed to condense > about 80 years of lessons learned into a labor > saving product that didn't introduce new risks > or radically modify normal and abnormal operating > instructions. > > One would hope that producers of EXB-Bus, EFII > et. als. had some philosophy founded in good > FMEA outcomes while maximizing flexibility of > application for the greatest number of builders. > Sadly, I'm seeing little, if any, consideration > for such matters in these products. > > This is why I am reluctant to suggest work-arounds > for problem like yours. Offering a personal band-aid > on a poorly designed accessory might easily be > mis-interpreted as some kind of agreement with > the design of the product. Suffice it to say that > there are good reasons why I would not be able to > qualify those products onto a TC aircraft under > the rules in place when I was last involved in > such things. > > Having said all that, I'll suggest you locate your > MANL as close as practical to the EFII battery(+) > terminal and tie it in there. This will FUNCTION > but it's a really scuzzy band-aid. > > Bob . . . > ________________________________ Message 5 _____________________________________ Time: 09:45:36 AM PST US From: Ken Ryan Subject: Re: AeroElectric-List: Re: B&C switches Good point Joe, regarding future maintenance considerations. But that is not a safety issue. Bob said that the Bus Manager is poorly designed in that it appears to him that a proper FEMA analysis was not conducted. I'm not arguing the point, but I do think such a statement should be accompanied by the specifics that back up the opinion. (Much the same as if someone declared Bob's OV module is poorly designed without providing any specifics.) Incidentally, the "newfangled" OV module suffers a similar problem of very limited availability. On Tue, Jul 17, 2018 at 4:31 AM user9253 wrote: > > Nothing lasts forever, including the newfangled electronic bus managers. > When something goes wrong, the whole box must be sent back to the > manufacturer for repair, if they are still in business. Compare that to > conventional wiring when a fuse blows. Yes, electrical knowledge is > required to figure out why the fuse blew. But the aircraft is still > flyable without that one circuit, which any mechanic can troubleshoot. > Fuses are just as easy to install as the electronic box and cost a whole > lot less. > Being able to view the current draw of each circuit on the EFIS screen > is a nice feature. But wouldn't it be better to be looking out the windows > and to do troubleshooting when on the ground? > > -------- > Joe Gores > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=481691#481691 > > ________________________________ Message 6 _____________________________________ Time: 10:02:39 AM PST US Subject: AeroElectric-List: Fwd: Re: Question for Bob From: "user9253" Rocketman1988, Your reasoning is valid. The chances of two contactors failing on a single flight are infinitesimal. Infinitesimal is defined as the the amount an aircraft carrier sinks in the water when a fly lands on its deck. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=481703#481703 ________________________________ Message 7 _____________________________________ Time: 10:39:52 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: B&C switches At 07:26 AM 7/17/2018, you wrote: > >Nothing lasts forever, including the newfangled electronic bus >managers. When something goes wrong, the whole box must be sent >back to the manufacturer for repair, if they are still in >business. Compare that to conventional wiring when a fuse >blows. Yes, electrical knowledge is required to figure out why the >fuse blew. But the aircraft is still flyable without that one >circuit, which any mechanic can troubleshoot. Fuses are just as >easy to install as the electronic box and cost a whole lot less. > Being able to view the current draw of each circuit on the EFIS > screen is a nice feature. But wouldn't it be better to be looking > out the windows and to do troubleshooting when on the ground? A good question. A friend of mine was offered a 'heck of a deal" on a new hay baler. $thousands$ in discounts. Emacs! The dealer even brought it out and hooked it up to his tractor some 55 miles from his dealership. I was astounded at the complexity of this machine compared with the 20 year old JD bailer that was supposed to get retired. This new machine had cables, sensors, actuators, electronic control box and a long bundle of wires that routed up to the cab of the tractor to communicate with a touch-screen control panel. The following day (with the dealer having gone home) several hours were expended trying to figure out how to get this marvel of agricultural technology to wake up. It even got the attention of neighboring farmers who had identical machines. Two days later, the dealer was back and discovered that a particular but critical cable assembly was not installed. After fixing that error, the machine lit up, sang Dixie and said, "Lets go roll up that hay." The following week, my friend was loading a new roll of netting when a cable assembly got tangled in some moving part and got ripped out of the connector and broke something else. Dealer came back and opined that repairs would only take $3,000 worth of parts and the 'good' news was that they were in stock in Wichita . . . they would be in tomorrow. A couple more days later, the machine was back in the field spitting out thousand pound bales of feed. Direct losses for the downtime were pretty impressive not to mention indirect losses for delays in getting feed out of the field before it got too dry. I could not help but wonder if his old baler could not have been refurbished for a whole lot less money. Better yet, it uses technology that was well understood, spare parts only 20 miles way and talents to repair were in possession of the owner! The fine art of striving for market success goes far deeper than getting excited about having incorporated the latest gee-whiz features. More than once, I've often stared at the screen on my 'smart phone' wishing I had more control over what it did well . . . and being able to dump what I don't need (about 75% of what's installed). Someone once opined, "Sometimes the best way to drive a nail is with a hammer." Bob . . . ________________________________ Message 8 _____________________________________ Time: 10:46:30 AM PST US Subject: AeroElectric-List: Electronic Bus Manager Versus Fuses & Breakers From: "user9253" What I do not like to see is an electrically-challenged builder installing a bus manager because he thinks that doing so will be easier than using fuses or circuit breakers. I do not think it is any easier. On the other hand, if a builder is knowledgeable about electronics and wants to have the latest and greatest gizmos including a bus manager, then fine. To each his own. I prefer fuses for simplicity and less cost and less weight. And fused circuits are easy for me to troubleshoot. Sometimes the choice is not a matter of right or wrong, but rather two or more ways to accomplish the goal, each being acceptable. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=481705#481705 ________________________________ Message 9 _____________________________________ Time: 11:48:58 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Failure Mode Effects Analysis At 11:44 AM 7/17/2018, you wrote: >Good point Joe, regarding future maintenance considerations. But >that is not a safety issue. Bob said that the Bus Manager is poorly >designed in that it appears to him that a proper FEMA analysis was >not conducted. I'm not arguing the point, but I do think such a >statement should be accompanied by the specifics that back up the >opinion. (Much the same as if someone declared Bob's OV module is >poorly designed without providing any specifics.) Incidentally, the >"newfangled" OV module suffers a similar problem of very limited availability. Conducting an FEMA is a process of considering the consequences of perhaps hundreds of simple failures with respect to: 1. How are the ways that this particular component can fail? 2. How would this particular failure manifest in terms of system performance? 3. Does the failure elevate risk for a comfortable termination of flight? 4. How would the pilot become aware of that failure? 5. Is the system fitted with a means by which that failure can be mitigated? 6. Is the failure pre-flight detectable? If not, should a means for pre-flight testing or in-flight annunciation be incorporated? Deducing the answer to these questions for EVERY part of an airplane allows the competent and experienced observer to write a report that speaks to the rational for sprinkling holy-water on the collection of parts that make up a component of the overall system. FMEA can and should be applied to every part of a system whether a nut and screw or a transistor in the EFCI. To be sure there are few really critical parts but unless they are identified and accounted for, the system is burdened with unnecessary and perhaps catastrophic risk. The goal is to achieve a high level of confidence that the system is failure tolerant. This means that probable failures are either (1) insignificant with respect to comfortable termination of flight or (2) have backup plans that makes the failure insignificant. This is the foundation for my assertions that there should be no reason that OBAM aircraft should not be fitted with out-of-reach fuse panels. The ultimate salute to the FAA requirement for carrying spares for all 'critical' fuses is to eliminate all critical fuses. Crew awareness of failures is an important part of the analysis. I.e. no high risk failure should be allowed to go un-noticed . . . ideally, annunciated in flight or identified during pre-flight. Beyond the FMEA, there are cost of ownership issues. Some of which are obvious based on lessons learned; others that won't manifest until the marketplace has a chance to conduct the real-life studies. My concerns for devices like EFII, EXP-Bus extend beyond FMEA to also cover cost-of- ownership and abandonment of legacy design goals. Bob . . . ________________________________ Message 10 ____________________________________ Time: 12:08:33 PM PST US Subject: AeroElectric-List: Fwd: Re: Question for Bob From: "Rocketman1988" As the OP, I wanted to ask Bob, specifically, a question. The title was meant to do just that. I do, however, agree with you that there is a good discussion goin on. Not sure if I can change the title, I will try... Read this topic online here: http://forums.matronics.com/viewtopic.php?p=481707#481707 ________________________________ Message 11 ____________________________________ Time: 02:24:10 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Fwd: Re: Question for Bob At 02:07 PM 7/17/2018, you wrote: > > >As the OP, I wanted to ask Bob, specifically, a question. The title >was meant to do just that. I do, however, agree with you that there >is a good discussion goin on. Not sure if I can change the title, I will try... Don't worry about it. "Thread creep" is a very common phenomenon during such discussions. It's exacerbated by my own scrambling of responses when dealing with more than one thread. Thread titles can be quickly obsoleted. Bob . . . ________________________________ Message 12 ____________________________________ Time: 02:25:52 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Cost effective technology At 07:26 AM 7/17/2018, you wrote: > >Nothing lasts forever, including the newfangled electronic bus >managers. When something goes wrong, the whole box must be sent >back to the manufacturer for repair, if they are still in >business. Compare that to conventional wiring when a fuse >blows. Yes, electrical knowledge is required to figure out why the >fuse blew. But the aircraft is still flyable without that one >circuit, which any mechanic can troubleshoot. Fuses are just as >easy to install as the electronic box and cost a whole lot less. > Being able to view the current draw of each circuit on the EFIS > screen is a nice feature. But wouldn't it be better to be looking > out the windows and to do troubleshooting when on the ground? A good question. A friend of mine was offered a 'heck of a deal" on a new hay baler. $thousands$ in discounts. Emacs! The dealer even brought it out and hooked it up to his tractor some 55 miles from his dealership. I was astounded at the complexity of this machine compared with the 20 year old JD bailer that was supposed to get retired. This new machine had cables, sensors, actuators, electronic control box and a long bundle of wires that routed up to the cab of the tractor to communicate with a touch-screen control panel. The following day (with the dealer having gone home) several hours were expended trying to figure out how to get this marvel of agricultural technology to wake up. It even got the attention of neighboring farmers who had identical machines. Two days later, the dealer was back and discovered that a particular but critical cable assembly was not installed. After fixing that error, the machine lit up, sang Dixie and said, "Lets go roll up that hay." The following week, my friend was loading a new roll of netting when a cable assembly got tangled in some moving part and got ripped out of the connector and broke something else. Dealer came back and opined that repairs would only take $3,000 worth of parts and the 'good' news was that they were in stock in Wichita . . . they would be in tomorrow. A couple more days later, the machine was back in the field spitting out thousand pound bales of feed. Direct losses for the downtime were pretty impressive not to mention indirect losses for delays in getting feed out of the field before it got too dry. I could not help but wonder if his old baler could not have been refurbished for a whole lot less money. Better yet, it uses technology that was well understood, spare parts only 20 miles way and talents to repair were in possession of the owner! The fine art of striving for market success goes far deeper than getting excited about having incorporated the latest gee-whiz features. More than once, I've often stared at the screen on my 'smart phone' wishing I had more control over what it did well . . . and being able to dump what I don't need (about 75% of what's installed). Someone once opined, "Sometimes the best way to drive a nail is with a hammer." Bob . . . ________________________________ Message 13 ____________________________________ Time: 03:16:51 PM PST US Subject: Re: AeroElectric-List: Re: B&C switches From: Charlie England Ken, There was a long discussion on this list about multiple single points of failure in the Bus Manager device, and there have been several threads on the VAF forum discussing multiple single points of failure in the device. Here's one: http://www.vansairforce.com/community/showthread.php?t=146753&highlight=bus+manager Unfortunately, the VAF forum owner considers his profit margin more important than the service his members supply (for free), so all the images have disappeared. But you should be able to get some idea from just the text in that thread. The response of Robert Paisley (face of Bus Manager's parent company) is that 'there have been no failures so far, so move along; nothing to see here'. You can kludge stuff around it to make the total a/c system somewhat less vulnerable to single failures in the Bus Manager taking down the whole system, but why pay the big bucks, only to have to do that? On 7/17/2018 11:44 AM, Ken Ryan wrote: > Good point Joe, regarding future maintenance considerations. But that > is not a safety issue. Bob said that the Bus Manager is poorly > designed in that it appears to him that a proper FEMA analysis was not > conducted. I'm not arguing the point, but I do think such a statement > should be accompanied by the specifics that back up the opinion. (Much > the same as if someone declared Bob's OV module is poorly designed > without providing any specifics.) Incidentally, the "newfangled" OV > module suffers a similar problem of very limited availability. > > On Tue, Jul 17, 2018 at 4:31 AM user9253 > wrote: > > > > > Nothing lasts forever, including the newfangled electronic bus > managers. When something goes wrong, the whole box must be sent > back to the manufacturer for repair, if they are still in > business. Compare that to conventional wiring when a fuse blows. > Yes, electrical knowledge is required to figure out why the fuse > blew. But the aircraft is still flyable without that one circuit, > which any mechanic can troubleshoot. Fuses are just as easy to > install as the electronic box and cost a whole lot less. > Being able to view the current draw of each circuit on the EFIS > screen is a nice feature. But wouldn't it be better to be looking > out the windows and to do troubleshooting when on the ground? > > -------- > Joe Gores > --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 14 ____________________________________ Time: 03:23:07 PM PST US From: FLYaDIVE Subject: Re: AeroElectric-List: Re: B&C switches =8BStar Trek's Scotty =8Bsaid it best: The more complicated th ey make it the easier it is to destroy. OK, I'm not accurate in the quote, but you get the idea. Barry PS I'm NOT a Trek-ie! On Tue, Jul 17, 2018 at 1:39 PM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 07:26 AM 7/17/2018, you wrote: > > > Nothing lasts forever, including the newfangled electronic bus managers. > When something goes wrong, the whole box must be sent back to the > manufacturer for repair, if they are still in business. Compare that to > conventional wiring when a fuse blows. Yes, electrical knowledge is > required to figure out why the fuse blew. But the aircraft is still > flyable without that one circuit, which any mechanic can troubleshoot. > Fuses are just as easy to install as the electronic box and cost a whole > lot less. > Being able to view the current draw of each circuit on the EFIS screen > is a nice feature. But wouldn't it be better to be looking out the windo ws > and to do troubleshooting when on the ground? > > > A good question. A friend of mine was offered a 'heck of > a deal" on a new hay baler. $thousands$ in discounts. > > [image: Emacs!] > > > The dealer even brought it out and hooked it up to his > tractor some 55 miles from his dealership. I was astounded > at the complexity of this machine compared with the > 20 year old JD bailer that was supposed to get retired. > > This new machine had cables, sensors, actuators, electronic > control box and a long bundle of wires that routed up to > the cab of the tractor to communicate with a touch-screen > control panel. > > The following day (with the dealer having gone home) > several hours were expended trying to figure out how > to get this marvel of agricultural technology to wake > up. It even got the attention of neighboring farmers > who had identical machines. Two days later, the dealer > was back and discovered that a particular but critical > cable assembly was not installed. After fixing that > error, the machine lit up, sang Dixie and said, "Lets > go roll up that hay." > > The following week, my friend was loading a new > roll of netting when a cable assembly got tangled > in some moving part and got ripped out of the connector > and broke something else. Dealer came back and opined > that repairs would only take $3,000 worth of parts > and the 'good' news was that they were in stock in > Wichita . . . they would be in tomorrow. > > A couple more days later, the machine was back in the > field spitting out thousand pound bales of feed. > Direct losses for the downtime were pretty impressive > not to mention indirect losses for delays in getting > feed out of the field before it got too dry. > > I could not help but wonder if his old baler could > not have been refurbished for a whole lot less money. > Better yet, it uses technology that was well understood, > spare parts only 20 miles way and talents to repair > were in possession of the owner! > > The fine art of striving for market success goes > far deeper than getting excited about having incorporated > the latest gee-whiz features. More than once, I've often > stared at the screen on my 'smart phone' wishing > I had more control over what it did well . . . and > being able to dump what I don't need (about 75% of > what's installed). > > Someone once opined, "Sometimes the best way to > drive a nail is with a hammer." > > Bob . . . > ------------------------------------------------------------------------------------- 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.