---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 01/28/20: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:10 AM - Z-14 implementation for SDS (Krea Ellis) 2. 05:53 AM - Re: Z-14 implementation for SDS (Robert L. Nuckolls, III) 3. 07:04 AM - Re: Z-14 implementation for SDS (Ernest Christley) 4. 07:19 AM - This doesn't seem right, but what do I know (Paul Zimmer) 5. 07:38 AM - Re: This doesn't seem right, but what do I know (Robert L. Nuckolls, III) 6. 07:42 AM - Z-14 implementation for SDS (Krea Ellis) 7. 08:04 AM - Re: Z-14 implementation for SDS (Charlie England) 8. 08:28 AM - Re: Plan-B fuel flow . . . (Robert L. Nuckolls, III) 9. 08:49 AM - Re: This doesn't seem right, but what do I know (Paul Zimmer) 10. 11:05 AM - Re: This doesn't seem right, but what do I know (Charlie England) 11. 05:01 PM - To Krea: the Q. you haven't asked yet :-) (Charlie England) 12. 05:29 PM - Re: Proposed Z-14 implementation (johnbright) 13. 06:18 PM - Re: Plan-B fuel flow . . . (johnbright) 14. 07:47 PM - Re: Replacing an EGT Probe (Art Zemon) ________________________________ Message 1 _____________________________________ Time: 03:10:32 AM PST US From: Krea Ellis Subject: AeroElectric-List: Z-14 implementation for SDS Ive tried to register to log in, but no luck - so I have to post a new thread. Sorry. Z14 architecture. As with John Bright, the issue is powering the injectors. All other components are redundant (ECU, fuel pump, 6 cylinder coil pack) and can be powered by an individual hot battery bus - protected by CBs and controlled by a Honeywell TL switch. My dilemma for the injectors is whether or not to power them from a Schottky diode protected injector bus, fed by each hot battery bus - or power them through a double pole triple throw switch. Normal position - 3 injectors powered by their respective hot battery bus, or all injectors powered by either A or B hot battery bus - with all power running through the TL switch. If the injector bus loses power for whatever reason, the engine dies. Trying to decide which architecture is the most reliable. Thank you. ________________________________ Message 2 _____________________________________ Time: 05:53:25 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Z-14 implementation for SDS >If the injector bus=9D loses power for whatever reason, the engine dies. > >Trying to decide which architecture is the most reliable. But what might be the reason? 99.999% of the time, when a bus looses power, it's because the source of power for that bus was lost . . .not because of any catastrophic failure of wiring and/or bus structure. This is a good topic for conducting an artful FMEA. I posed the question earlier: Assume all injectors are powered from the z-14 aux bus. What failure of a device would bring down the bus in a manner that had no handy mitigation i.e. a plan-B? Bob . . . ________________________________ Message 3 _____________________________________ Time: 07:04:13 AM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Z-14 implementation for SDS On Tuesday, January 28, 2020, 6:10:55 AM EST, Krea Ellis wrote: If the =9Cinjector bus=9D loses power for whatever reason, the engine dies. The Wright brother had an engine that dripped fuel into a bowl at the intak e.=C2- That method doesn't give a lot of control, but it still works.=C2 - If you can gravity feed fuel, you might consider running a line to some place on the intake and control it with a needle valve. ________________________________ Message 4 _____________________________________ Time: 07:19:39 AM PST US From: Paul Zimmer Subject: AeroElectric-List: This doesn't seem right, but what do I know I use and monitor two Hall effect current sensors on my RV. One measures the current flow on the "B" lead from the main alternator, and the other measures the current flow to/from the main battery. What doesn't make sense to me is there are periodic and frequent current flows to/from the battery (1 to 5 amps) during normal cruise operations, this during periods of static and relatively light load (12-15 amps) on the electrical system, much smaller than the capacity of the 60A Plane Power alternator. I would expect all power to be supplied directly from the alternator as it is supplying the current at a higher voltage (~14.5v or so) than the battery. These periods of flow to/from the battery are short in duration normally lasting only a few seconds. Is this normal and to be expected, or does it suggest a problem with the internally regulated alternator, or perhaps with the current sensor itself? Any insight explaining what I am seeing will be appreciated. Thanks ________________________________ Message 5 _____________________________________ Time: 07:38:05 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: This doesn't seem right, but what do I know >These periods of flow to/from the battery are short >in duration normally lasting only a few seconds. > >Is this normal and to be expected, or does it >suggest a problem with the internally regulated >alternator, or perhaps with the current sensor itself? > >Any insight explaining what I am seeing will be appreciated. The battery's physics reacts to BUS VOLTAGE. Any period battery energy outflow MUST be paired with a drop in bus voltage to something below the battery's present open-circuit voltage. The voltage doesn't have to drop to the battery's natural delivery level (~12.5 volts for SVLA) . . . a battery across an operating bus will support small outflow currents at voltages higher than 12.5. What is your normal bus voltage and do you notice any depression of voltage that corresponds to battery outflow events? Bob . . . ________________________________ Message 6 _____________________________________ Time: 07:42:01 AM PST US From: Krea Ellis Subject: AeroElectric-List: Z-14 implementation for SDS Ive tried to register to log in, but no luck - so I have to post a new thread. Sorry. Z14 architecture. As with John Bright, the issue is powering the injectors. All other components are redundant (ECU, fuel pump, 6 cylinder coil pack) and can be powered by an individual hot battery bus - protected by CBs and controlled by a Honeywell TL switch. My dilemma for the injectors is whether or not to power them from a Schottky diode protected injector bus, fed by each hot battery bus - or power them through a double pole triple throw switch. Normal position - 3 injectors powered by their respective hot battery bus, or all injectors powered by either A or B hot battery bus - with all power running through the TL switch. If the injector bus loses power for whatever reason, the engine dies. Trying to decide which architecture is the most reliable. Thank you. ________________________________ Message 7 _____________________________________ Time: 08:04:04 AM PST US Subject: Re: AeroElectric-List: Z-14 implementation for SDS From: Charlie England On 1/28/2020 5:08 AM, Krea Ellis wrote: > > Ive tried to register to log in, but no luck - so I have to post a new thread. Sorry. > > Z14 architecture. As with John Bright, the issue is powering the injectors. All other components are redundant (ECU, fuel pump, 6 cylinder coil pack) and can be powered by an individual hot battery bus - protected by CBs and controlled by a Honeywell TL switch. > > My dilemma for the injectors is whether or not to power them from a Schottky diode protected injector bus, fed by each hot battery bus - or power them through a double pole triple throw switch. Normal position - 3 injectors powered by their respective hot battery bus, or all injectors powered by either A or B hot battery bus - with all power running through the TL switch. > > If the injector bus loses power for whatever reason, the engine dies. > > Trying to decide which architecture is the most reliable. Well, most safety related analysis techniques I've read about tend to assign 'reliable' to stuff we can't make redundant or for which we can't supply an alternative, like wings and other structure. If it's reasonably possible to provide an alternative for a safety of flight item, we *assume* that it can fail, *regardless of its reliability*, and provide an alternative (ex: pitch trim backs up direct pitch control from the stick). If you route all power for the injectors through a single multi-section switch, a mechanical failure of the switch (no matter how 'reliable') can take out all power to all injectors. In my opinion, it fails failure mode analysis, since there's no 'plan B' for a mechanical switch failure. Charlie ________________________________ Message 8 _____________________________________ Time: 08:28:33 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Plan-B fuel flow . . . At 09:00 AM 1/28/2020, you wrote: >On Tuesday, January 28, 2020, 6:10:55 AM EST, >Krea Ellis wrote: > >If the =9Cinjector bus=9D loses power for whatever reason, the engine dies. > > >The Wright brother had an engine that dripped >fuel into a bowl at the intake. That method >doesn't give a lot of control, but it still >works. If you can gravity feed fuel, you might >consider running a line to someplace on the >intake and control it with a needle valve. Speaking of redundant fuel delivery systems, I'm recalling a conversation from waaayyy back in the dark ages . . . I think it was prompted by the John Denver crash in a LongEz. The investigators theorized that he ran a tank dry and may have stood on a rudder pedal trying to reach a fuel tank selector handle causing loss of control under engine-out conditions. The conversation debated a desire by some Ez owners not to have to run three fuel lines the length of the cockpit to a more conveniently located selector valve. I suggested an alternative, no-valve, all electric approach to fuel management on canard-pusher aircraft. Emacs! The suggestion also provided an alternative, completely independent, fuel delivery system. 4-port primer systems were a functional possibility for most Ez engines. I had recalled several "I leaned about flying from that" stories wherein a pilot brought his ship to a comfortable landing using a primer pump to keep the engine delivering useful power. So why not install an on-purpose, primer/run system? The pump driven, primer system would feed from one tank, the main fuel supply from the other tank. A third pump would transfer fuel from the left tank to the right tank. A needle valve in the primer line would be used to calibrate primer fuel flow to approximate that needed for 70% or so power. Don't know how many of these system were installed but I did get a report from one reader that did a calibrated, 4-port installation and flight tested it. He said it worked nicely. This arrangement had a high probability of enabling a graceful return to earth in case of problems in the primary fuel delivery system. Light, cheap, low energy requirements and completely independent of primary system. Bob . . . ________________________________ Message 9 _____________________________________ Time: 08:49:38 AM PST US From: Paul Zimmer Subject: Re: AeroElectric-List: This doesn't seem right, but what do I know I can=99t say that I=99ve noticed a bus voltage drop during the se times of battery outflow, but before I say one way or the other, I=99ll need t o pay a little closer attention, and perhaps record the engine monitor parameters during a flight which would allow for an after the fact thorough analysis of what actually went on. I=99ll circle back at a later date. Thank s On Tue, Jan 28, 2020 at 10:43 AM Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > > > These periods of flow to/from the battery are short > in duration normally lasting only a few seconds. > > Is this normal and to be expected, or does it > suggest a problem with the internally regulated > alternator, or perhaps with the current sensor itself? > > Any insight explaining what I am seeing will be appreciated. > > > The battery's physics reacts to BUS VOLTAGE. > Any period battery energy outflow MUST be > paired with a drop in bus voltage to something > below the battery's present open-circuit > voltage. > > The voltage doesn't have to drop to > the battery's natural delivery > level (~12.5 volts for SVLA) . . . > a battery across an operating bus > will support small outflow currents > at voltages higher than 12.5. > > What is your normal bus voltage and do > you notice any depression of voltage > that corresponds to battery outflow > events? > > > Bob . . . > ________________________________ Message 10 ____________________________________ Time: 11:05:30 AM PST US Subject: Re: AeroElectric-List: This doesn't seem right, but what do I know From: Charlie England If you were using a shunt, I'd suggest checking any fuseholders used to protect the sense wires. Any minor variations in resistance in the sense lines can cause significant instrument error, showing discharge. Charlie On 1/28/2020 10:46 AM, Paul Zimmer wrote: > I cant say that Ive noticed a bus voltage drop during these times of > battery outflow, but before I say one way or the other, Ill need to > pay a little closer attention, and perhaps record the engine monitor > parameters during a flight which would allow for an after the fact > thorough analysis of what actually went on. Ill circle back at a > later date. Thanks > > On Tue, Jan 28, 2020 at 10:43 AM Robert L. Nuckolls, III > > > wrote: > > > >> These periods of flow to/from the battery are short >> in duration normally lasting only a few seconds. >> >> Is this normal and to be expected, or does it >> suggest a problem with the internally regulated >> alternator, or perhaps with the current sensor itself? >> >> Any insight explaining what I am seeing will be appreciated. > > The battery's physics reacts to BUS VOLTAGE. > Any period battery energy outflow MUST be > paired with a drop in bus voltage to something > below the battery's present open-circuit > voltage. > > The voltage doesn't have to drop to > the battery's natural delivery > level (~12.5 volts for SVLA) . . . > a battery across an operating bus > will support small outflow currents > at voltages higher than 12.5. > > What is your normal bus voltage and do > you notice any depression of voltage > that corresponds to battery outflow > events? > > > Bob . . . > ________________________________ Message 11 ____________________________________ Time: 05:01:30 PM PST US From: Charlie England Subject: AeroElectric-List: To Krea: the Q. you haven't asked yet :-) I installed these in my RV6. The '2 seats with 5Lv' model will give you what you're looking for. https://www.ebay.com/itm/Car-Seat-Heater-Kit-Carbon-Fiber-Universal-Heated-Cushion-Warmer-2-level-5-level/253250702661?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 Hope that helps, Charlie ________________________________ Message 12 ____________________________________ Time: 05:29:24 PM PST US Subject: AeroElectric-List: Re: Proposed Z-14 implementation From: "johnbright" nuckolls.bob(at)aeroelect wrote: > At 02:29 PM 1/27/2020, you wrote: > > Okay, riddle me this . . . suppose all injectors were > powered from the aux bus of Z14. Deduced and cite the > failure that would bring the aux bus down . . . and > what would be the mitigating action? > > > Bob . . . Thanks Bob, The feed to the bus itself could be interrupted resulting in engine stoppage. It is unlikely to lose a bus feed but not impossible; probably due to poor craftsmanship which in my anecdotal experience occurs too often. Also in an electrical fire in the cockpit scenario the crew would take the main and aux power buses down. I took a shot a bus config trade study for electronic injection + ignition; attached as a gif and in my filespace linked from my signature. -------- John Bright, RV-6A, at FWF, O-360, dual SDSEFI EM-5-F Dual Batt Dual Alt RV-6A SDS dual EM-5-F john_s_bright@yahoo.com, Newport News, Va Read this topic online here: http://forums.matronics.com/viewtopic.php?p=494516#494516 Attachments: http://forums.matronics.com//files/bus_config_trades_for_electronic_injection__ignition_rev_01282020_819.jpg ________________________________ Message 13 ____________________________________ Time: 06:18:38 PM PST US Subject: AeroElectric-List: Re: Plan-B fuel flow . . . From: "johnbright" Dave Anders did something like this on his SDS EFI RV-4: http://www.vansairforce.com/community/showpost.php?p=1191654&postcount=140 Some photos of his RV-4: http://www.sdsefi.com/dave.htm -------- John Bright, RV-6A, at FWF, O-360, dual SDSEFI EM-5-F Dual Batt Dual Alt RV-6A SDS dual EM-5-F john_s_bright@yahoo.com, Newport News, Va Read this topic online here: http://forums.matronics.com/viewtopic.php?p=494517#494517 ________________________________ Message 14 ____________________________________ Time: 07:47:51 PM PST US From: Art Zemon Subject: Re: AeroElectric-List: Replacing an EGT Probe Thanks, folks. I'll try one of the old EGT probes and see if it works. Cheers, -- Art Z. -- https://CheerfulCurmudgeon.com/ *Love the stranger for you yourselves were strangers in Egypt. *Deut. 10:19 ------------------------------------------------------------------------------------- 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.