---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 11/11/21: 11 ---------------------------------------------------------- Today's Message Index: ---------------------- 0. 10:00 AM - List Contribution - Value of the List... (Matt Dralle) 1. 08:07 AM - Z-101 schematic question (heedh23) 2. 10:09 AM - Re: Re: RV-10 Electrical Review with Electric AC and FlyEFII (ashleysc@broadstripe.net) 3. 10:50 AM - Re: Z-101 schematic question (Charlie England) 4. 01:26 PM - Re: Z-101 schematic question (johnbright) 5. 04:56 PM - Re: Re: RV-10 Electrical Review with Electric AC and FlyEFII (Charlie England) 6. 05:23 PM - Re: Re: RV-10 Electrical Review with Electric AC and FlyEFII (ashleysc@broadstripe.net) 7. 05:24 PM - O Re: RV-10 Electrical Review with Electric AC and FlyEFI (melstien) 8. 05:43 PM - O Re: RV-10 Electrical Review with Electric AC and FlyEF (melstien) 9. 06:05 PM - Re: O Re: RV-10 Electrical Review with Electric AC and FlyEF (Kelly McMullen) 10. 07:28 PM - Re: EFII System32 (Sebastien) ________________________________ Message 0 _____________________________________ Time: 10:00:36 AM PST US From: Matt Dralle Subject: AeroElectric-List: List Contribution - Value of the List... If you look forward to checking your List email everyday (and a lot of you have written to say that you do!), then you're probably getting at least $20 or $30 worth of Entertainment from the Lists each year. You'd pay twice that for a subscription to some magazine or even a dinner out. Isn't the List worth at least that much to you? Wouldn't it be great if you could pay that amount and get a well-managed media source free of advertising, SPAM, and viruses? Come to think of it, you do... :-) Won't you please take a minute to make your Contribution today and support these Lists? https://matronics.com/contribution Or, drop a personal check in the mail to: Matt Dralle / Matronics 581 Jeannie Way Livermore CA 94550 USA I want to say THANK YOU to everyone that has made a Contribution thus far during this year's List Fund Raiser!! These Lists are made possible exclusively through YOUR generosity!! Thank you for your support! Matt Dralle Email List Admin. ________________________________ Message 1 _____________________________________ Time: 08:07:38 AM PST US Subject: AeroElectric-List: Z-101 schematic question From: "heedh23" Hi all- Following the current Z-101 / RV-10 discussion with interest, as I am beginning to plan out my own electrical system. Two n00b questions for my education- 1. What is the significance of the B in a circle symbol near the aux/engine bus feeder diode, the primary alternator field breaker, and the aux bus relay? I couldnt find a definition for that symbol in my copy of the Aeroelectric Connection. 2. I am currently flying an OBAM SeaRey, which has long battery runs from nose battery to pusher engine, plus a composite hull. The RV-10 reverses the position of the battery / engine, but has similar long power runs. I got used to running thick wire through the hull :). My question - if the main bus fuse distribution occurs just behind the firewall and the battery is in the rear, why not power the main bus via the heavy gauge wire running from the alternator B lead/starter solenoid back to the hot side of the battery contactor rather than running a separate bus feed from the rear-mounted contactor back to the bus? I recognize that the weight of the smaller gauge bus power lead is small, and inexpensive, but it seems like a similar optimization is already happening between the starter and B lead. Merely curious. Thanks in advance, -Ed Read this topic online here: http://forums.matronics.com/viewtopic.php?p=504165#504165 ________________________________ Message 2 _____________________________________ Time: 10:09:24 AM PST US From: ashleysc@broadstripe.net Subject: Re: AeroElectric-List: Re: RV-10 Electrical Review with Electric AC and FlyEFII Hi Charlie; Hi All; I apologize beforehand if this comment is out of context. I didn't read all the foregoing. But I'll make it brief: 1. The aircraft has two fuel tanks, one in each wing. 2. It has a "Main " pump which can draw from either tank and two "Auxiliary " pumps (a right aux and a left aux). 3. Any one of these three pumps were proved to be able to provide 1.9 to 2. 0 times the requisite fuel for wide open throttle, with the aircraft tilted at 20 degrees up attitude and one gallon of fuel remaining in the tanks. 4. Since the carburetor has a pressure regulator and vapor return line, the pumps cannot over-pressure the system. 5. Each pump has its own switch/circuit breaker. 6.The pump failure mode is to "fail open," that is fuel will flow through a failed pump. 7. There are two 20 amp alternators in the aircraft, which can operate sing ly or in parallel. 8. So, to summarize: It would take the failure of three pumps, or three swi tches, or two alternators to incapacitate the aircraft. Cheers! Stu. ----- Original Message ----- From: "Charlie England" Sent: Wednesday, November 10, 2021 2:15:52 PM Subject: Re: AeroElectric-List: Re: RV-10 Electrical Review with Electric A C and FlyEFII It *might* work, if you could dial the pressure up to electronic injection levels. The pump is possibly capable of that much pressure; but I just don' t know if Andair would configure it that way. There's also the issue of add itive pressure, though I suppose that if you kept the bypass regulator betw een the 2nd pump & the engine, it would probably work. I'd want test data; either my own or the pump mfgr's before installing that kind of setup. I just downloaded the System32 install manual and scrolled down to the powe r wiring page. I tried to find the Bus Manager install manual (ref by the N OTE on this page), but couldn't find it on their web site. Comments are bas ed on what I can see, with available docs from the mfgr that I could find. Looking at the diagram, I see three (3) (scratch that; at least 6; likely q uite a few more if I could see inside the box) single points of failure, on this one page, any one of which *would* stop the engine. Depending on how you count failures, I can see closer to a dozen. All of those failure modes are hardware related; they don't count control logic (inside the 'black bo xes'), which I can't see. Now some of them are quite unlikely, but some hav e a much higher probability of occurring, and there are relatively simple f ixes for all of them. (Doing FMEA doesn't really look at probabilities; it looks at Effects .) I keep coming back to the mantra of: if it's nearly imp ossible to make redundant (like the wing spar, or only one throttle body on the engine), I'll evaluate and likely accept the risk, but if it's relativ ely easy to provide a backup for flight critical items, I'm going to find a way to do it. Please believe me when I say I'm truly not trying to be insulting, but I wo uld not want to fly in a plane wired like that. There's just not a diplomat ic way to tell someone that an easily corrected thing could kill them if no t corrected. If I haven't offended you System32 users too much and you're i nterested, we can discuss some of the failure modes and ideas to fix them. Charlie On 11/10/2021 2:59 PM, Sebastien wrote: No argument about other black boxes Charlie, I was just trying to point out that the EFII fuel pump black box is a control circuit, not a power circui t. The output to the fuel pump relay is one wire. If the black box end of t hat wire goes to ground, or open, or 15v, or whatever, the fuel pump keeps running. As for inline fuel pumps, I hadn't run into that problem yet. Would this no t work? Andair Products On Wed, Nov 10, 2021 at 10:51 AM Charlie England < ceengland7@gmail.com > w rote:
Your example of the GNS + VOR/ILS is the perfect example of proper 'what if ' thinking; if the GNS availability is down for any reason, you have an ind ependent method of accomplishing your goal. 'Black box' control of the fuel pumps (or any other multiple device backup system) might or might not meet those criteria. It's been demonstrated that some of them do not accomplish this, and some have been demonstrated to have failure modes that can take out *everything* they supply power to. I'm just trying to point out that sa ying that it's worked for X hours or Y years just says that you haven't see n a failure mode yet that could affect both the primary and the backup. Wit hout analyzing the circuits in the box, you don't know the failure modes. C ompletely different situation from two separate radio systems with separate power sources, antennas, etc. My point about the fuel pumps is knowing the product when it isn't 'traditi onal'. The fuel pumps used by FLYEFII (and others) for electronic injection are *not* like traditional fuel pumps. Unlike traditional Lyc engine drive n pumps, and unlike the traditional boost pumps, those Walbro pumps will *n ot* pass fuel if they aren't running. I don't know of any 'different pump' that you could run that would supply t he needed ~40 PSI and could still be run in series without any issues. If y ou know of one, please share the info; it could well simplify a lot of EFI installations. Charlie On 11/10/2021 11:58 AM, Sebastien wrote:
Or just use different pumps and run them in series (the way a legacy system is installed) instead of in parallel with FLYEFII's manifold.
As a FYI, the Walbro pumps shown on FLYEFII's web page are positive displac ement pumps. That means that if the pump isn't turning, no fuel will move t hrough that pump. See the problem with that thought path?
I can't say that I do Charlie:
Or just use different pumps and run them in series (the way a legacy system is installed) instead of in parallel with FLYEFII's manifold.
When selecting fuel pumps, the ability to flow fuel when not turning has be en a basic requirement for series fuel pumps for about a century. The fuel flow test performed before first flight will demonstrate whether or not the correct pumps have been selected. As for the black box, it is completely unnecessary to analyze the failure m odes and their effects since any failure of the box (including a bad temper ed Gremlin eating the box and leaving the wires dangling) will either leave the relay powering the primary fuel pump as normal, or erroneously switch to backup. The particular aircraft I've been working on has been flying aro und with a failed black box since day one. The black box is in a different country than the aircraft. The pump still runs. Similarly the Mooney I fly has a complicated Garmin GNS Navigator and a bac kup VOR/ILS. I have no need to analyse the different failure modes of the G armin in order to be confident that if it fails, I can use the other VOR/IL S. I just tune, identify, switch HSI source, set course, and set the desire d autopilot mode. However relay failures are something I know nothing about. If a likely fail ure mode of this relay could leave both pumps unpowered then the FLYEFII im plementation is poor. I haven't seen any data to suggest this but I'll ask them what research and testing they did next time I speak with them. On Wed, Nov 10, 2021 at 9:06 AM Charlie England < ceengland7@gmail.com > wr ote:
Everyone sets their own comfort level when it comes to risk. If you're happ y *and you're fully informed about the risks*, then that's your choice. I m ight make different choices, and some of mine on other subjects might be un acceptable to you. Do you *know* what's in the black box? Have you analyzed the failure modes and their effects? A fuel line failure would be difficult to 'plan around', except through careful and thoughtful installation work. But electrical fa ilure issues are relatively simple to plan for and to implement backup syst ems for potential failures. I'm just trying to point out that there are som e whizbang gadgets that can introduce more failure modes than they compensa te for, and we need to know when that is happening. I'd have more confidence in a vendor's position if he told me that he teste d for a potential problem, rather than just speculation. For instance, I as ked one of the a/c fuel boost pump (for conventional fuel injection) vendor s about their technique of looping bypassed fuel back to the inlet of the p ump and the risks of vapor lock/cavitation. His response was that they'd te sted it, including at elevated fuel temps. There's also the contrary data p oint that competitors' systems (using very similar dual pump setups) work j ust fine when running both pumps for takeoff & landing. I really want to understand as well as possible any system I install that's a departure from 'tradition', simply because failure modes will be differe nt and likely not as well documented. For instance, this: Or just use different pumps and run them in series (the way a legacy system is installed) instead of in parallel with FLYEFII's manifold. As a FYI, the Walbro pumps shown on FLYEFII's web page are positive displac ement pumps. That means that if the pump isn't turning, no fuel will move t hrough that pump. See the problem with that thought path? Charlie On 11/10/2021 10:17 AM, Sebastien wrote:
Charlie if the "black box" that switches fuel pumps fails, the primary fuel pump continues to run so no worries. The relay that switches pumps is NO p assing current to the primary pump, or energized and switching current to t he backup pump. I suppose the relay itself could be mechanically damaged an d shut off both pumps, but a fuel line could break cutting off fuel as well . The FLYEFII Bus Manager is expensive and requires two batteries, but it's a ctually a pretty well thought out unit. It just occurred to me that in our high wing we're not worried about cavita ting the pumps if we run both, but in an RV-10 it could be a concern. So in stead of fancy switching logic, install a third pump to feed the two EFII p umps and run all three for takeoff :). Or just use different pumps and run them in series (the way a legacy system is installed) instead of in paralle l with FLYEFII's manifold. On Wed, Nov 10, 2021 at 7:11 AM Charlie England < ceengland7@gmail.com > wr ote:
The fuel pump symptoms you describe are totally normal. If you run both pum ps, they will each require their own full rated current while running. Tota l fuel pressure shouldn't change more than a few PSI if the regulator is si zed properly. Excess fuel is bypassed by the regulator back to the tank. Up side is that if one pump fails during a critical phase of flight, fuel deli very doesn't even 'hiccup'. Auto-switching of the pumps: If that's totally inside your 'black box', do you *know* that black box doesn't have a single-point-of-failure inside? Kn owing means having the schematic for the guts of the black box, and a full understanding of the circuit. If you're using B&C regulators, I believe that the regulator is powered via pin 6 ('bus'). The various pins and their functions are described in their manual, here . Not sure why they labeled pin 3 as 'OV' since the manual sa ys overvoltage is sensed at the supply pin (6). Pin 3 is a 'remote sense' l ine that the regulator uses to accurately measure bus voltage so it can set proper voltage, and does the secondary job of detecting *under* (low) volt age. I can't specifically address the EFII system, but coil packs typically cons ume fairly low current, compared to the injectors. Injectors can have relat ively high inrush current each time they fire. This: " They have the coil packs and the injectors all being fed by 1 15 am p fuse. " just *screams* SINGLE POINT OF FAILURE at me. I could be wrong, b ut I'd want to be absolutely certain about it. Play what if. Short one wire to ground or short one coil internally to ground, etc, somewhere downstrea m of that fuse. What happens to the engine? Charlie On Tue, Nov 9, 2021 at 8:48 PM melstien < michael@elstien.us > wrote:
Hello John, Yes, I like to keep track of my changes so I try to add revision tags. I do n't always remember. I will take a look at the failure modes and probably better align this to t he Z101 and also try to organize it so it makes physical sense. That will a lso allow me to see where all my connection points should be. Currently it is just electrically correct (or will be if people suggest good changes) I will add separate filed switches on the alternators. I was not sure and t hat was one of my questions. The 40 Amp AC will be an experiment. I do not plan to add it to the alterna tor load except during level flight at altitude and near an airport. AC is a luxury. The Earthex batteries can draw at least 100 amps continuously so I think they will pick up any sag and my IBBS batteries on critical avionic s are also meant to do that as well. Engine Bus answers: 6 Cylinder as opposed to a 4 cylinder Yes, everything will have its own power lead and the coil packs will have a fusable link and a breaker Injectors will have a fusible link only I planned to not have the pump on automatice failover but to run them both during takeoff, landing and fuel tank switch-overs but Robert at FLYEFII di d not suggest that. he thought it might cause cavitation on the inlet. My t esting using my actual fuel lines and pressure regulator indicated that run ning both at the same time more than doubled the current draw (4.9 amps per pump solo) and the fule flow increased marginally. I think they were both fighting each other to supply pressure at the pump outlet and it was still only going through qty 1 -3/8 inch hose. I had thought about splicing each injector wire and coil pack power feed in to 2 wires and feeding them off Engine Bus A and engine Bus B all with diod e isolation. The schematic looked cool but it introduced to many connection s points which would probably have increased failures. FLYEFII suggests a 10 Amp fuse for the for the pumps and my load testing in dicates they only use 4.9 when run separately. I can review the wires size I used and see if it will support a 12 or 15 amp breaker. FlyEFII did not state what the coil pack would need when powered separately . They have the coil packs and the injectors all being fed by 1 15 amp fuse . I suspect that the coil packs will still need a 15 amp fuse per coil pack because they all charge at different times, so splitting them into 3 does not reduce the peak current, just the frequency it occurs. (I am a Mech Eng ineer so I am looking for guidance on that.) I have reached out to FLY EFII and requested guidance. FlyEFII informed me that the system at high RPM will consume 11 AMPs. That is all I have to go on. to meet my 1 hour of reserve, I can always move up the ETX 1200 battery. Its the same form factor and will carry an 18 amp loa d for 80 minutes. If that is not enough there is always the ETX1600 (120Amp /hours). Even two of the 1200's weight less than 1 PC680. Money is just the issue. Not a place to skimp. Regarding the coil packs, cylinder 1-4 are spread across coil packs A and B so they are redundant. If you lose A or B you still have 1 working plug pe r cylinder 1-4. FLY EFII added the 3rd coil pack and both plugs for cylinde rs 5 and 6 are on the same pack. I have informed FLYEFII that I would sugge st a different arrangement so both plugs were not on the same coil pack. I do know of a person who lost coil pack C and the engine ran without too muc h vibration, but I need to check into that story. I have 2 LR3Ds and the higher output backup alternator. I just noticed they come with an amber light. I will ties these outputs into my EFIS but a goo d light is also nice. I Prefer LED for lower heat and better vibration and longer life. OV Sense, so this is the contact that senses the buss voltage and is used t o increase or decrease the voltage ouput? I have them both going to the Mai n Bus, but maybe the backup should go to the engine bus. There is a possibi lity the main bus has power but the engine bus does not. Your thoughts? I reviewed your diagram and it is really what I intended mine to be, only w ith the second battery. Thanks for the feedback. I appreciate it. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=504060#504060
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________________________________ Message 3 _____________________________________ Time: 10:50:56 AM PST US Subject: Re: AeroElectric-List: Z-101 schematic question From: Charlie England On 11/11/2021 10:07 AM, heedh23 wrote: > > Hi all- > > Following the current Z-101 / RV-10 discussion with interest, as I am beginning to plan out my own electrical system. > > Two n00b questions for my education- > > 1. What is the significance of the B in a circle symbol near the aux/engine bus feeder diode, the primary alternator field breaker, and the aux bus relay? I couldnt find a definition for that symbol in my copy of the Aeroelectric Connection. > > 2. I am currently flying an OBAM SeaRey, which has long battery runs from nose battery to pusher engine, plus a composite hull. The RV-10 reverses the position of the battery / engine, but has similar long power runs. I got used to running thick wire through the hull :). My question - if the main bus fuse distribution occurs just behind the firewall and the battery is in the rear, why not power the main bus via the heavy gauge wire running from the alternator B lead/starter solenoid back to the hot side of the battery contactor rather than running a separate bus feed from the rear-mounted contactor back to the bus? I recognize that the weight of the smaller gauge bus power lead is small, and inexpensive, but it seems like a similar optimization is already happening between the starter and B lead. Merely curious. > > Thanks in advance, > -Ed No clue on the B symbol, but I think you're describing the 'typical' wiring method for rear bat/firewall main bus. The master contactor is at the battery, and the load side wire comes forward to the starter solenoid's hot side, and from there it can feed the main bus. Here's an old hand drawn 'rear battery' setup that Bob did years ago for the Z14 diagram. Not the exact thing you're describing, but electrically the same, if you eliminate the extra battery & crossfeed contactor. Charlie -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 4 _____________________________________ Time: 01:26:05 PM PST US Subject: AeroElectric-List: Re: Z-101 schematic question From: "johnbright" heedh23 wrote: > ...What is the significance of the B in a circle symbol near the aux/engine bus feeder diode, the primary alternator field breaker, and the aux bus relay?... > > Thanks in advance, > -Ed The circled Bs are changes at rev B. At rev A there was no diode part number, the aux bus feeder was 18 awg, and the main alternator field was thru 16 awg FLW followed by 12 awg hookup wire to the 5A breaker. BTW, in former times, Bob used shop-made 22 awg fuse links followed by 18 awg hookup wire. He went to store-bought fuselink wire recently and the smallest available in small quantities is 20 awg. -------- John Bright, RV-6A, at FWF, O-360 Z-101 single batt dual alt SDS EM-5-F. john_s_bright@yahoo.com, Newport News, Va https://drive.google.com/folderview?id=1u6GeZo6pmBWsKykLNVQMvu4o1VEVyP4K Read this topic online here: http://forums.matronics.com/viewtopic.php?p=504247#504247 ________________________________ Message 5 _____________________________________ Time: 04:56:10 PM PST US Subject: Re: AeroElectric-List: Re: RV-10 Electrical Review with Electric AC and FlyEFII From: Charlie England Hi Stu, I'm not sure we're talking about the same a/c and/or fuel delivery system. I think there may be 2 or 3 different installations mentioned in this thread; I've lost track of who is running which system. Is yours a carb engine, and not running the System32? If so, most or possibly all of my comments would not apply to your system. If running a carb, did you add the regulator/return line to reduce vapor lock issues, or for some other reason? All the carb'd Lycs I've operated just have the fuel line 'dead end' at the carb inlet. Which electric pumps are you running? Are you still running the engine driven pump? Sorry for any confusion, Charlie On 11/11/2021 12:08 PM, ashleysc@broadstripe.net wrote: > Hi Charlie; > Hi All; > I apologize beforehand if this comment is out of context. I didn't > read all the foregoing. But I'll make it brief: > 1. The aircraft has two fuel tanks, one in each wing. > 2. It has a "Main " pump which can draw from either tank and two > "Auxiliary" pumps (a right aux and a left aux). > 3. Any one of these three pumps were proved to be able to provide 1.9 > to 2.0 times the requisite fuel for wide open throttle, with the > aircraft tilted at 20 degrees up attitude and one gallon of fuel > remaining in the tanks. > 4. Since the carburetor has a pressure regulator and vapor return > line, the pumps cannot over-pressure the system. > 5. Each pump has its own switch/circuit breaker. > 6.The pump failure mode is to "fail open," that is fuel will flow > through a failed pump. > 7. There are two 20 amp alternators in the aircraft, which can operate > singly or in parallel. > 8. So, to summarize: It would take the failure of three pumps, or > three switches, or two alternators to incapacitate the aircraft. > Cheers! Stu. > > ------------------------------------------------------------------------ > *From: *"Charlie England" > *To: *aeroelectric-list@matronics.com > *Sent: *Wednesday, November 10, 2021 2:15:52 PM > *Subject: *Re: AeroElectric-List: Re: RV-10 Electrical Review with > Electric AC and FlyEFII > > It *might* work, if you could dial the pressure up to electronic > injection levels. The pump is possibly capable of that much pressure; > but I just don't know if Andair would configure it that way. There's > also the issue of additive pressure, though I suppose that if you kept > the bypass regulator between the 2nd pump & the engine, it would > probably work. I'd want test data; either my own or the pump mfgr's > before installing that kind of setup. > > I just downloaded the System32 install manual and scrolled down to the > power wiring page. I tried to find the Bus Manager install manual (ref > by the NOTE on this page), but couldn't find it on their web site. > Comments are based on what I can see, with available docs from the > mfgr that I could find. > > Looking at the diagram, I see three (3) (scratch that; at least 6; > likely quite a few more if I could see inside the box) single points > of failure, on this one page, any one of which *would* stop the > engine. Depending on how you count failures, I can see closer to a > dozen. All of those failure modes are hardware related; they don't > count control logic (inside the 'black boxes'), which I can't see. Now > some of them are quite unlikely, but some have a much higher > probability of occurring, and there are relatively simple fixes for > all of them. (Doing FMEA doesn't really look at probabilities; it > looks at /Effects/.) I keep coming back to the mantra of: if it's > nearly impossible to make redundant (like the wing spar, or only one > throttle body on the engine), I'll evaluate and likely accept the > risk, but if it's relatively easy to provide a backup for flight > critical items, I'm going to find a way to do it. > > Please believe me when I say I'm truly not trying to be insulting, but > I would not want to fly in a plane wired like that. There's just not a > diplomatic way to tell someone that an easily corrected thing could > kill them if not corrected. If I haven't offended you System32 users > too much and you're interested, we can discuss some of the failure > modes and ideas to fix them. > > Charlie > > > On 11/10/2021 2:59 PM, Sebastien wrote: > > No argument about other black boxes Charlie, I was just trying to > point out that the EFII fuel pump black box is a control circuit, > not a power circuit. The output to the fuel pump relay is one > wire. If the black box end of that wire goes to ground, or open, > or 15v, or whatever, the fuel pump keeps running. > > As for inline fuel pumps, I hadn't run into that problem yet. > Would this not work? > > Andair Products > > > On Wed, Nov 10, 2021 at 10:51 AM Charlie England > wrote: > > Your example of the GNS + VOR/ILS is the perfect example of > proper 'what if' thinking; if the GNS availability is down for > any reason, you have an independent method of accomplishing > your goal. 'Black box' control of the fuel pumps (or any other > multiple device backup system) might or might not meet those > criteria. It's been demonstrated that some of them do not > accomplish this, and some have been demonstrated to have > failure modes that can take out *everything* they supply power > to. I'm just trying to point out that saying that it's worked > for X hours or Y years just says that you haven't seen a > failure mode yet that could affect both the primary and the > backup. Without analyzing the circuits in the box, you don't > know the failure modes. Completely different situation from > two separate radio systems with separate power sources, > antennas, etc. > > My point about the fuel pumps is knowing the product when it > isn't 'traditional'. The fuel pumps used by FLYEFII (and > others) for electronic injection are *not* like traditional > fuel pumps. Unlike traditional Lyc engine driven pumps, and > unlike the traditional boost pumps, those Walbro pumps will > *not* pass fuel if they aren't running. > > I don't know of any 'different pump' that you could run that > would supply the needed ~40 PSI and could still be run in > series without any issues. If you know of one, please share > the info; it could well simplify a lot of EFI installations. > > Charlie > > > On 11/10/2021 11:58 AM, Sebastien wrote: > > Or just use different pumps and run them in series > (the way a legacy system is installed) instead of in > parallel with FLYEFII's manifold. > > > As a FYI, the Walbro pumps shown on FLYEFII's web page > are positive displacement pumps. That means that if > the pump isn't turning, no fuel will move through that > pump. See the problem with that thought path? > > > I can't say that I do Charlie: > > Or just use different pumps and run them in series > (the way a legacy system is installed) instead of in > parallel with FLYEFII's manifold. > > > When selecting fuel pumps, the ability to flow fuel when > not turning has been a basic requirement for series fuel > pumps for about a century. The fuel flow test performed > before first flight will demonstrate whether or not the > correct pumps have been selected. > > As for the black box, it is completely unnecessary to > analyze the failure modes and their effects since any > failure of the box (including a bad tempered Gremlin > eating the box and leaving the wires dangling) will either > leave the relay powering the primary fuel pump as > normal,or erroneously switch to backup. The particular > aircraft I've been working on has been flying around with > a failed black box since day one. The black box is in a > different country than the aircraft. The pump still runs. > > Similarly the Mooney I fly has a complicated Garmin GNS > Navigator and a backup VOR/ILS. I have no need to analyse > the different failure modes of the Garmin in order to be > confident that if it fails, I can use the other VOR/ILS. I > just tune, identify, switch HSI source, set course, and > set the desired autopilot mode. > > However relay failures are something I know nothing about. > If a likely failure mode of this relay could leave both > pumps unpowered then the FLYEFII implementation is poor. I > haven't seen any data to suggest this but I'll ask them > what research and testing they did next time I speak with > them. > > On Wed, Nov 10, 2021 at 9:06 AM Charlie England > wrote: > > Everyone sets their own comfort level when it comes to > risk. If you're happy *and you're fully informed about > the risks*, then that's your choice. I might make > different choices, and some of mine on other subjects > might be unacceptable to you. > > Do you *know* what's in the black box? Have you > analyzed the failure modes and their effects? A fuel > line failure would be difficult to 'plan around', > except through careful and thoughtful installation > work. But electrical failure issues are relatively > simple to plan for and to implement backup systems for > potential failures. I'm just trying to point out that > there are some whizbang gadgets that can introduce > more failure modes than they compensate for, and we > need to know when that is happening. > > I'd have more confidence in a vendor's position if he > told me that he tested for a potential problem, rather > than just speculation. For instance, I asked one of > the a/c fuel boost pump (for conventional fuel > injection) vendors about their technique of looping > bypassed fuel back to the inlet of the pump and the > risks of vapor lock/cavitation. His response was that > they'd tested it, including at elevated fuel temps. > There's also the contrary data point that competitors' > systems (using very similar dual pump setups) work > just fine when running both pumps for takeoff & landing. > > I really want to understand as well as possible any > system I install that's a departure from 'tradition', > simply because failure modes will be different and > likely not as well documented. For instance, this: > Or just use different pumps and run them in series > (the way a legacy system is installed) instead of in > parallel with FLYEFII's manifold. > > As a FYI, the Walbro pumps shown on FLYEFII's web page > are positive displacement pumps. That means that if > the pump isn't turning, no fuel will move through that > pump. See the problem with that thought path? > > Charlie > > On 11/10/2021 10:17 AM, Sebastien wrote: > > Charlie if the "black box" that switches fuel > pumps fails, the primary fuel pump continues to > run so no worries. The relay that switches pumps > is NO passing current to the primary pump, or > energized and switching current to the backup > pump. I suppose the relay itself could be > mechanically damaged and shut off both pumps, but > a fuel line could break cutting off fuel as well. > > The FLYEFII Bus Manager is expensive and requires > two batteries, but it's actually a pretty well > thought out unit. > > It just occurred to me that in our high wing we're > not worried about cavitating the pumps if we run > both, but in an RV-10 it could be a concern. So > instead of fancy switching logic, install a > /third/pump to feed the two EFII pumps and run > all three for takeoff :). Or just use different > pumps and run them in series (the way a legacy > system is installed) instead of in parallel with > FLYEFII's manifold. > > On Wed, Nov 10, 2021 at 7:11 AM Charlie England > wrote: > > The fuel pump symptoms you describe are > totally normal. If you run both pumps, they > will each require their own full rated current > while running. Total fuel pressure shouldn't > change more than a few PSI if the regulator is > sized properly. Excess fuel is bypassed by the > regulator back to the tank. Upside is that if > one pump fails during a critical phase of > flight, fuel delivery doesn't even 'hiccup'. > > Auto-switching of the pumps: If that's totally > inside your 'black box', do you *know* that > black box doesn't have a > single-point-of-failure inside? Knowing means > having the schematic for the guts of the black > box, and a full understanding of the circuit. > > If you're using B&C regulators, I believe that > the regulator is powered via pin 6 ('bus'). > The various pins and their functions are > described in their manual, here > . > Not sure why they labeled pin 3 as 'OV' since > the manual says overvoltage is sensed at the > supply pin (6). Pin 3 is a 'remote sense' line > that the regulator uses to accurately measure > bus voltage so it can set proper voltage, and > does the secondary job of detecting *under* > (low) voltage. > I can't specifically address the EFII system, > but coil packs typically consume fairly low > current, compared to the injectors. Injectors > can have relatively high inrush current each > time they fire. > This: "/They have the coil packs and the > injectors all being fed by 1 15 amp fuse./" > just *screams* SINGLE POINT OF FAILURE at me. > I could be wrong, but I'd want to be > absolutely certain about it. Play what if. > Short one wire to ground or short one coil > internally to ground,etc, somewhere > downstream of that fuse. What happens to the > engine? > > Charlie > > > On Tue, Nov 9, 2021 at 8:48 PM melstien > wrote: > > "melstien" > > Hello John, > > Yes, I like to keep track of my changes so > I try to add revision tags. I don't > always remember. > > I will take a look at the failure modes > and probably better align this to the Z101 > and also try to organize it so it makes > physical sense. That will also allow me > to see where all my connection points > should be. Currently it is just > electrically correct (or will be if people > suggest good changes) > > I will add separate filed switches on the > alternators. I was not sure and that > was one of my questions. > > The 40 Amp AC will be an experiment. I > do not plan to add it to the alternator > load except during level flight at > altitude and near an airport. AC is a > luxury. The Earthex batteries can draw at > least 100 amps continuously so I think > they will pick up any sag and my IBBS > batteries on critical avionics are also > meant to do that as well. > > Engine Bus answers: > 6 Cylinder as opposed to a 4 cylinder > Yes, everything will have its own power > lead and the coil packs will have a > fusable link and a breaker > Injectors will have a fusible link only > I planned to not have the pump on > automatice failover but to run them both > during takeoff, landing and fuel tank > switch-overs but Robert at FLYEFII did not > suggest that. he thought it might cause > cavitation on the inlet. My testing > using my actual fuel lines and pressure > regulator indicated that running both at > the same time more than doubled the > current draw (4.9 amps per pump solo) and > the fule flow increased marginally. I > think they were both fighting each other > to supply pressure at the pump outlet and > it was still only going through qty 1 -3/8 > inch hose. > I had thought about splicing each injector > wire and coil pack power feed into 2 wires > and feeding them off Engine Bus A and > engine Bus B all with diode isolation. > The schematic looked cool but it > introduced to many connections points > which would probably have increased failures. > > FLYEFII suggests a 10 Amp fuse for the for > the pumps and my load testing indicates > they only use 4.9 when run separately. I > can review the wires size I used and see > if it will support a 12 or 15 amp breaker. > > FlyEFII did not state what the coil pack > would need when powered separately. They > have the coil packs and the injectors all > being fed by 1 15 amp fuse. I suspect > that the coil packs will still need a 15 > amp fuse per coil pack because they all > charge at different times, so splitting > them into 3 does not reduce the peak > current, just the frequency it occurs. (I > am a Mech Engineer so I am looking for > guidance on that.) I have reached out to > FLY EFII and requested guidance. > > FlyEFII informed me that the system at > high RPM will consume 11 AMPs. That is > all I have to go on. to meet my 1 hour > of reserve, I can always move up the ETX > 1200 battery. Its the same form factor > and will carry an 18 amp load for 80 > minutes. If that is not enough there is > always the ETX1600 (120Amp/hours). Even > two of the 1200's weight less than 1 > PC680. Money is just the issue. Not a > place to skimp. > > Regarding the coil packs, cylinder 1-4 are > spread across coil packs A and B so they > are redundant. If you lose A or B you > still have 1 working plug per cylinder > 1-4. FLY EFII added the 3rd coil pack and > both plugs for cylinders 5 and 6 are on > the same pack. I have informed FLYEFII > that I would suggest a different > arrangement so both plugs were not on the > same coil pack. I do know of a person > who lost coil pack C and the engine ran > without too much vibration, but I need to > check into that story. > > I have 2 LR3Ds and the higher output > backup alternator. I just noticed they > come with an amber light. I will ties > these outputs into my EFIS but a good > light is also nice. I Prefer LED for > lower heat and better vibration and longer > life. > > OV Sense, so this is the contact that > senses the buss voltage and is used to > increase or decrease the voltage ouput? I > have them both going to the Main Bus, but > maybe the backup should go to the engine > bus. There is a possibility the main bus > has power but the engine bus does not. > Your thoughts? > > I reviewed your diagram and it is really > what I intended mine to be, only with the > second battery. > > Thanks for the feedback. I appreciate it. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=504060#504060 > > > > Virus-free. www.avast.com > > > -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 6 _____________________________________ Time: 05:23:42 PM PST US From: ashleysc@broadstripe.net Subject: Re: AeroElectric-List: Re: RV-10 Electrical Review with Electric AC and FlyEFII Hi Charlie; Yes, the aircraft has a carb mfg. by Rotec in Australia. The vapor return i s mainly to eliminate vapor lock and create faster starting. The carb has a pressure regulator and primer built in. The aircraft has no engine driven (mechanical) pump, only the three Facet pumps mentioned. I mainly posted my comment because there was a lot of discussion about failure modes and redu ndancy in the previous posts. I wanted to suggest a system such as mine cou ld have redundancy without being complicated or expensive. I appreciate you r comments. Cheers! Stu. ----- Original Message ----- From: "Charlie England" Sent: Thursday, November 11, 2021 5:00:27 PM Subject: Re: AeroElectric-List: Re: RV-10 Electrical Review with Electric A C and FlyEFII Hi Stu, I'm not sure we're talking about the same a/c and/or fuel delivery system. I think there may be 2 or 3 different installations mentioned in this threa d; I've lost track of who is running which system. Is yours a carb engine, and not running the System32? If so, most or possibly all of my comments wo uld not apply to your system. If running a carb, did you add the regulator/return line to reduce vapor lo ck issues, or for some other reason? All the carb'd Lycs I've operated just have the fuel line 'dead end' at the carb inlet. Which electric pumps are you running? Are you still running th e engine driven pump? Sorry for any confusion, Charlie On 11/11/2021 12:08 PM, ashleysc@broadstripe.net wrote: Hi Charlie; Hi All; I apologize beforehand if this comment is out of context. I didn't read all the foregoing. But I'll make it brief: 1. The aircraft has two fuel tanks, one in each wing. 2. It has a "Main " pump which can draw from either tank and two "Auxiliary " pumps (a right aux and a left aux). 3. Any one of these three pumps were proved to be able to provide 1.9 to 2. 0 times the requisite fuel for wide open throttle, with the aircraft tilted at 20 degrees up attitude and one gallon of fuel remaining in the tanks. 4. Since the carburetor has a pressure regulator and vapor return line, the pumps cannot over-pressure the system. 5. Each pump has its own switch/circuit breaker. 6.The pump failure mode is to "fail open," that is fuel will flow through a failed pump. 7. There are two 20 amp alternators in the aircraft, which can operate sing ly or in parallel. 8. So, to summarize: It would take the failure of three pumps, or three swi tches, or two alternators to incapacitate the aircraft. Cheers! Stu. ----- Original Message ----- From: "Charlie England" Sent: Wednesday, November 10, 2021 2:15:52 PM Subject: Re: AeroElectric-List: Re: RV-10 Electrical Review with Electric A C and FlyEFII It *might* work, if you could dial the pressure up to electronic injection levels. The pump is possibly capable of that much pressure; but I just don' t know if Andair would configure it that way. There's also the issue of add itive pressure, though I suppose that if you kept the bypass regulator betw een the 2nd pump & the engine, it would probably work. I'd want test data; either my own or the pump mfgr's before installing that kind of setup. I just downloaded the System32 install manual and scrolled down to the powe r wiring page. I tried to find the Bus Manager install manual (ref by the N OTE on this page), but couldn't find it on their web site. Comments are bas ed on what I can see, with available docs from the mfgr that I could find. Looking at the diagram, I see three (3) (scratch that; at least 6; likely q uite a few more if I could see inside the box) single points of failure, on this one page, any one of which *would* stop the engine. Depending on how you count failures, I can see closer to a dozen. All of those failure modes are hardware related; they don't count control logic (inside the 'black bo xes'), which I can't see. Now some of them are quite unlikely, but some hav e a much higher probability of occurring, and there are relatively simple f ixes for all of them. (Doing FMEA doesn't really look at probabilities; it looks at Effects .) I keep coming back to the mantra of: if it's nearly imp ossible to make redundant (like the wing spar, or only one throttle body on the engine), I'll evaluate and likely accept the risk, but if it's relativ ely easy to provide a backup for flight critical items, I'm going to find a way to do it. Please believe me when I say I'm truly not trying to be insulting, but I wo uld not want to fly in a plane wired like that. There's just not a diplomat ic way to tell someone that an easily corrected thing could kill them if no t corrected. If I haven't offended you System32 users too much and you're i nterested, we can discuss some of the failure modes and ideas to fix them. Charlie On 11/10/2021 2:59 PM, Sebastien wrote:
No argument about other black boxes Charlie, I was just trying to point out that the EFII fuel pump black box is a control circuit, not a power circui t. The output to the fuel pump relay is one wire. If the black box end of t hat wire goes to ground, or open, or 15v, or whatever, the fuel pump keeps running. As for inline fuel pumps, I hadn't run into that problem yet. Would this no t work? Andair Products On Wed, Nov 10, 2021 at 10:51 AM Charlie England < ceengland7@gmail.com > w rote:
Your example of the GNS + VOR/ILS is the perfect example of proper 'what if ' thinking; if the GNS availability is down for any reason, you have an ind ependent method of accomplishing your goal. 'Black box' control of the fuel pumps (or any other multiple device backup system) might or might not meet those criteria. It's been demonstrated that some of them do not accomplish this, and some have been demonstrated to have failure modes that can take out *everything* they supply power to. I'm just trying to point out that sa ying that it's worked for X hours or Y years just says that you haven't see n a failure mode yet that could affect both the primary and the backup. Wit hout analyzing the circuits in the box, you don't know the failure modes. C ompletely different situation from two separate radio systems with separate power sources, antennas, etc. My point about the fuel pumps is knowing the product when it isn't 'traditi onal'. The fuel pumps used by FLYEFII (and others) for electronic injection are *not* like traditional fuel pumps. Unlike traditional Lyc engine drive n pumps, and unlike the traditional boost pumps, those Walbro pumps will *n ot* pass fuel if they aren't running. I don't know of any 'different pump' that you could run that would supply t he needed ~40 PSI and could still be run in series without any issues. If y ou know of one, please share the info; it could well simplify a lot of EFI installations. Charlie On 11/10/2021 11:58 AM, Sebastien wrote:
Or just use different pumps and run them in series (the way a legacy system is installed) instead of in parallel with FLYEFII's manifold.
As a FYI, the Walbro pumps shown on FLYEFII's web page are positive displac ement pumps. That means that if the pump isn't turning, no fuel will move t hrough that pump. See the problem with that thought path?
I can't say that I do Charlie:
Or just use different pumps and run them in series (the way a legacy system is installed) instead of in parallel with FLYEFII's manifold.
When selecting fuel pumps, the ability to flow fuel when not turning has be en a basic requirement for series fuel pumps for about a century. The fuel flow test performed before first flight will demonstrate whether or not the correct pumps have been selected. As for the black box, it is completely unnecessary to analyze the failure m odes and their effects since any failure of the box (including a bad temper ed Gremlin eating the box and leaving the wires dangling) will either leave the relay powering the primary fuel pump as normal, or erroneously switch to backup. The particular aircraft I've been working on has been flying aro und with a failed black box since day one. The black box is in a different country than the aircraft. The pump still runs. Similarly the Mooney I fly has a complicated Garmin GNS Navigator and a bac kup VOR/ILS. I have no need to analyse the different failure modes of the G armin in order to be confident that if it fails, I can use the other VOR/IL S. I just tune, identify, switch HSI source, set course, and set the desire d autopilot mode. However relay failures are something I know nothing about. If a likely fail ure mode of this relay could leave both pumps unpowered then the FLYEFII im plementation is poor. I haven't seen any data to suggest this but I'll ask them what research and testing they did next time I speak with them. On Wed, Nov 10, 2021 at 9:06 AM Charlie England < ceengland7@gmail.com > wr ote:
Everyone sets their own comfort level when it comes to risk. If you're happ y *and you're fully informed about the risks*, then that's your choice. I m ight make different choices, and some of mine on other subjects might be un acceptable to you. Do you *know* what's in the black box? Have you analyzed the failure modes and their effects? A fuel line failure would be difficult to 'plan around', except through careful and thoughtful installation work. But electrical fa ilure issues are relatively simple to plan for and to implement backup syst ems for potential failures. I'm just trying to point out that there are som e whizbang gadgets that can introduce more failure modes than they compensa te for, and we need to know when that is happening. I'd have more confidence in a vendor's position if he told me that he teste d for a potential problem, rather than just speculation. For instance, I as ked one of the a/c fuel boost pump (for conventional fuel injection) vendor s about their technique of looping bypassed fuel back to the inlet of the p ump and the risks of vapor lock/cavitation. His response was that they'd te sted it, including at elevated fuel temps. There's also the contrary data p oint that competitors' systems (using very similar dual pump setups) work j ust fine when running both pumps for takeoff & landing. I really want to understand as well as possible any system I install that's a departure from 'tradition', simply because failure modes will be differe nt and likely not as well documented. For instance, this: Or just use different pumps and run them in series (the way a legacy system is installed) instead of in parallel with FLYEFII's manifold. As a FYI, the Walbro pumps shown on FLYEFII's web page are positive displac ement pumps. That means that if the pump isn't turning, no fuel will move t hrough that pump. See the problem with that thought path? Charlie On 11/10/2021 10:17 AM, Sebastien wrote:
Charlie if the "black box" that switches fuel pumps fails, the primary fuel pump continues to run so no worries. The relay that switches pumps is NO p assing current to the primary pump, or energized and switching current to t he backup pump. I suppose the relay itself could be mechanically damaged an d shut off both pumps, but a fuel line could break cutting off fuel as well . The FLYEFII Bus Manager is expensive and requires two batteries, but it's a ctually a pretty well thought out unit. It just occurred to me that in our high wing we're not worried about cavita ting the pumps if we run both, but in an RV-10 it could be a concern. So in stead of fancy switching logic, install a third pump to feed the two EFII p umps and run all three for takeoff :). Or just use different pumps and run them in series (the way a legacy system is installed) instead of in paralle l with FLYEFII's manifold. On Wed, Nov 10, 2021 at 7:11 AM Charlie England < ceengland7@gmail.com > wr ote:
The fuel pump symptoms you describe are totally normal. If you run both pum ps, they will each require their own full rated current while running. Tota l fuel pressure shouldn't change more than a few PSI if the regulator is si zed properly. Excess fuel is bypassed by the regulator back to the tank. Up side is that if one pump fails during a critical phase of flight, fuel deli very doesn't even 'hiccup'. Auto-switching of the pumps: If that's totally inside your 'black box', do you *know* that black box doesn't have a single-point-of-failure inside? Kn owing means having the schematic for the guts of the black box, and a full understanding of the circuit. If you're using B&C regulators, I believe that the regulator is powered via pin 6 ('bus'). The various pins and their functions are described in their manual, here . Not sure why they labeled pin 3 as 'OV' since the manual sa ys overvoltage is sensed at the supply pin (6). Pin 3 is a 'remote sense' l ine that the regulator uses to accurately measure bus voltage so it can set proper voltage, and does the secondary job of detecting *under* (low) volt age. I can't specifically address the EFII system, but coil packs typically cons ume fairly low current, compared to the injectors. Injectors can have relat ively high inrush current each time they fire. This: " They have the coil packs and the injectors all being fed by 1 15 am p fuse. " just *screams* SINGLE POINT OF FAILURE at me. I could be wrong, b ut I'd want to be absolutely certain about it. Play what if. Short one wire to ground or short one coil internally to ground, etc, somewhere downstrea m of that fuse. What happens to the engine? Charlie On Tue, Nov 9, 2021 at 8:48 PM melstien < michael@elstien.us > wrote:
Hello John, Yes, I like to keep track of my changes so I try to add revision tags. I do n't always remember. I will take a look at the failure modes and probably better align this to t he Z101 and also try to organize it so it makes physical sense. That will a lso allow me to see where all my connection points should be. Currently it is just electrically correct (or will be if people suggest good changes) I will add separate filed switches on the alternators. I was not sure and t hat was one of my questions. The 40 Amp AC will be an experiment. I do not plan to add it to the alterna tor load except during level flight at altitude and near an airport. AC is a luxury. The Earthex batteries can draw at least 100 amps continuously so I think they will pick up any sag and my IBBS batteries on critical avionic s are also meant to do that as well. Engine Bus answers: 6 Cylinder as opposed to a 4 cylinder Yes, everything will have its own power lead and the coil packs will have a fusable link and a breaker Injectors will have a fusible link only I planned to not have the pump on automatice failover but to run them both during takeoff, landing and fuel tank switch-overs but Robert at FLYEFII di d not suggest that. he thought it might cause cavitation on the inlet. My t esting using my actual fuel lines and pressure regulator indicated that run ning both at the same time more than doubled the current draw (4.9 amps per pump solo) and the fule flow increased marginally. I think they were both fighting each other to supply pressure at the pump outlet and it was still only going through qty 1 -3/8 inch hose. I had thought about splicing each injector wire and coil pack power feed in to 2 wires and feeding them off Engine Bus A and engine Bus B all with diod e isolation. The schematic looked cool but it introduced to many connection s points which would probably have increased failures. FLYEFII suggests a 10 Amp fuse for the for the pumps and my load testing in dicates they only use 4.9 when run separately. I can review the wires size I used and see if it will support a 12 or 15 amp breaker. FlyEFII did not state what the coil pack would need when powered separately . They have the coil packs and the injectors all being fed by 1 15 amp fuse . I suspect that the coil packs will still need a 15 amp fuse per coil pack because they all charge at different times, so splitting them into 3 does not reduce the peak current, just the frequency it occurs. (I am a Mech Eng ineer so I am looking for guidance on that.) I have reached out to FLY EFII and requested guidance. FlyEFII informed me that the system at high RPM will consume 11 AMPs. That is all I have to go on. to meet my 1 hour of reserve, I can always move up the ETX 1200 battery. Its the same form factor and will carry an 18 amp loa d for 80 minutes. If that is not enough there is always the ETX1600 (120Amp /hours). Even two of the 1200's weight less than 1 PC680. Money is just the issue. Not a place to skimp. Regarding the coil packs, cylinder 1-4 are spread across coil packs A and B so they are redundant. If you lose A or B you still have 1 working plug pe r cylinder 1-4. FLY EFII added the 3rd coil pack and both plugs for cylinde rs 5 and 6 are on the same pack. I have informed FLYEFII that I would sugge st a different arrangement so both plugs were not on the same coil pack. I do know of a person who lost coil pack C and the engine ran without too muc h vibration, but I need to check into that story. I have 2 LR3Ds and the higher output backup alternator. I just noticed they come with an amber light. I will ties these outputs into my EFIS but a goo d light is also nice. I Prefer LED for lower heat and better vibration and longer life. OV Sense, so this is the contact that senses the buss voltage and is used t o increase or decrease the voltage ouput? I have them both going to the Mai n Bus, but maybe the backup should go to the engine bus. There is a possibi lity the main bus has power but the engine bus does not. Your thoughts? I reviewed your diagram and it is really what I intended mine to be, only w ith the second battery. Thanks for the feedback. I appreciate it. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=504060#504060
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________________________________ Message 7 _____________________________________ Time: 05:24:51 PM PST US Subject: AeroElectric-List: O Re: RV-10 Electrical Review with Electric AC and FlyEFI From: "melstien" Hello Ron, I agree with your comments and thoughts. My goal upon any failure: Alternator or battery or... is the same as a it would be without EFII, which is to land as quickly as possible, not to continue the flight. I am trying to minimize how one failure causes the engine to get quiet. My goal of 1 hour of battery life is to enable proper time to get down from altitude in a location (think Central US or upstate NY) and in IFR conditions where landing my not be a simple task. If in VFR down here in Florida, we could be talking 5-10 minutes to the nearest airport. It sounds loike you like you like the System 32. Thank you for your comments. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=504250#504250 ________________________________ Message 8 _____________________________________ Time: 05:43:48 PM PST US Subject: AeroElectric-List: O Re: RV-10 Electrical Review with Electric AC and FlyEF From: "melstien" Hello Kelly, you are so right about weight and balance on the RV-10. Lighter weight batteries in the back will move the CG forward. What might be offsetting this is adding 2 batteries which may come close to the original PC680 weight but adds additional capacity. I also did not mention that I am seriously considering the newer Whirlwind 300-3B/B-77 propeller designed for the RV-10. It is lighter than the 2 blade Hazell by as much as 8-13 pounds on the nose. There a lot of variable to take into consideration. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=504252#504252 ________________________________ Message 9 _____________________________________ Time: 06:05:46 PM PST US Subject: Re: AeroElectric-List: O Re: RV-10 Electrical Review with Electric AC and FlyEF From: Kelly McMullen Sebastian, The original battery that Vans recommends is a Concorde RG-25AXC, which weighs about 24 lbs. I have the Odyssey equivalent, a PC925 at about the same weight. I have an MT 3 bladed prop, as the Whirlwind was not available when I built. It is also about 14 lbs lighter than the Hartzell 2 blade aluminum prop. I still need at least 50 lbs ballast in the baggage compartment if I don't have back seat passengers or baggage. Avoid a 3 bladed prop if you can get composite 2 bladed prop, as a 3 blade makes it very difficult to remove bottom cowling. Kelly On 11/11/2021 6:42 PM, melstien wrote: > > Hello Kelly, > > you are so right about weight and balance on the RV-10. Lighter weight batteries in the back will move the CG forward. What might be offsetting this is adding 2 batteries which may come close to the original PC680 weight but adds additional capacity. > > I also did not mention that I am seriously considering the newer Whirlwind 300-3B/B-77 propeller designed for the RV-10. It is lighter than the 2 blade Hazell by as much as 8-13 pounds on the nose. > > There a lot of variable to take into consideration. > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=504252#504252 > > > > > > > > > ________________________________ Message 10 ____________________________________ Time: 07:28:31 PM PST US From: Sebastien Subject: Re: AeroElectric-List: EFII System32 Thank you Charlie, 1. What is the failure mode of the relay that could kill the engine? 2. You mentioned DPDT switches can fail to both shorted, is this something that happens when you flip the switch or can the switch just be sitting there and fail? Thank you, Sebastien On Wed, Nov 10, 2021 at 5:44 PM Charlie England wrote: > On 11/10/2021 4:35 PM, Sebastien wrote: > > In a belated attempt to not derail Michael's electrical system thread, > > I'm starting this one to ask Charlie for more details on the possible > > problems with EFII's System32 fuel injection and ignition system when > > the electrical system architecture is based on the EFII Bus Manager. > > > > I have been hired to test fly an aircraft with this system. Haven't > > been able to get off the ground yet due to multiple setup problems and > > wiring mistakes but none of these were related to the Bus Manager. > > > > Charlie I would be very interested to hear anything you have to say > > FMEA wise about this system. > OK, for a start, here's a marked up copy of that page from the install > manual. I've likely overlooked some stuff in the quick run-through I > did, and could be more accurate with an internal schematic + board > layout of the Bus Manager. But I've marked six ways the system can kill > the engine, and highlighted a seventh *possible* way; I'd want to see > exactly how up to twelve fusible links are installed within the > backshell of the BM connector. Fusible links may or may not generate > enough heat to be a factor in any wire near them. They're typically > thermally insulated to protect other wires around them but they're > typically not tightly confined in an enclosure (the backshell, in this > case). > > As I said, it's difficult to completely evaluate the system without the > BM info. The drawing shows an external 'daisy chain' connection path > (circled in red) to the various components, but the yellow circled text > seems to indicate that path is inside the BM. Having said that, things > like the ECU select switch are likely to be external. > > Hope that's at least some food for thought, and maybe others will have > some input, as well. > > Charlie > > -- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > ------------------------------------------------------------------------------------- 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.