---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 02/03/09: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:36 AM - Re: Z-14 with dual Lightspeed III and SD-8 (Erich_Weaver@URSCorp.com) 2. 11:55 AM - Re: Re: Z-14 with dual Lightspeed III and SD-8 (RV Builder (Michael Sausen)) 3. 12:52 PM - Re: Re: Z-14 with dual Lightspeed III and SD-8 (Matt Prather) 4. 01:44 PM - Re: Re: Z-14 with dual Lightspeed III and SD-8 (RV Builder (Michael Sausen)) 5. 02:35 PM - Re: Re: Z-14 with dual Lightspeed III and SD-8 (Hinde, Frank George (Corvallis)) 6. 02:53 PM - Re: Re: Z-14 with dual Lightspeed III and SD-8 (Robert L. Nuckolls, III) 7. 03:18 PM - Re: Re: Z-14 with dual Lightspeed III and SD-8 (Robert L. Nuckolls, III) 8. 04:51 PM - Re: Re: Z-14 with dual Lightspeed III and SD-8 (RV Builder (Michael Sausen)) 9. 05:26 PM - Re: Z-14 with dual Lightspeed III and SD-8 (bcondrey) 10. 08:00 PM - Re: Re: Z-14 with dual Lightspeed III and SD-8 (Sam Hoskins) 11. 08:10 PM - Re: Re: Z-14 with dual Lightspeed III and SD-8 (Robert L. Nuckolls, III) 12. 08:53 PM - Dual Plasma III and Z-13/8..needing 2 x batteries and C/B's...?(Was Bob Nuckolls' Z-14 with Dual...) (Rob du Plooy) ________________________________ Message 1 _____________________________________ Time: 09:36:49 AM PST US Subject: AeroElectric-List: Re: Z-14 with dual Lightspeed III and SD-8 From: Erich_Weaver@URSCorp.com I dont think I am fully understanding this discussion. Bob, perhaps you could provide a simple summary of the issue and concerns here for the l ess enlightened? There are a lot of folks out here with single or dual lightspeed ignitions. Under what circumstances are they at risk? Any suggested course of action? A lot of concern seems to have been expres sed without much direct input from the manufacturer. erich ________________________________ Message 2 _____________________________________ Time: 11:55:28 AM PST US From: "RV Builder (Michael Sausen)" Subject: RE: AeroElectric-List: Re: Z-14 with dual Lightspeed III and SD-8 Thanks Bob for uncovering this. I had the same basic plan as you, using a fuse off each of the two main batteries running up each side of the fusel age to the two LSEIII's. I think knowing this now I will use a slightly larger fuse off the batter y, say 15amp with the appropriate wire of course, and then use breaker swit ches for the LSE's. My batteries are in the back and I certainly don't wan t two separate, unprotected wires running up the length of the fuselage. I f it's an OV and not enough to blow the 15amp fuses then I can reset the LS E's using the switch breakers. If it's something else that blows the 15amp , probably won't make a difference at that point as it's either a fried com ponent or a shorted wire. Does this sound like a workable solution to ever yone? Michael ________________________________ Message 3 _____________________________________ Time: 12:52:15 PM PST US Subject: RE: AeroElectric-List: Re: Z-14 with dual Lightspeed III and SD-8 From: "Matt Prather" I suspect such series protection will always blow the fuse and not the breaker - if they both have the same rating. The time constant for blowing most standard breakers is much slower than for fuses. You might be able to upsize the wiring and fuse and get something to work - by operating the fuse at a much smaller percentage of it's fault current rating than the breaker. You could also pick a device with a slower blow time than a normal ATC fuse. An MDL maybe? The behavior of the system might also depend on how "good" the short is that is presented by the LSE's internal crow bar. The peak current wouldn't likely be anywhere close to that of connecting copper straight across the battery terminals. The impedance of the crowbar comes into play. One question I can't remember being asked/answered is what voltage the LSE's crowbar is designed to trip at. I suspect it might be quite high as I think the systems are allowed to be run from a 24(28)V bus - the manual lists proper operation up to 35V. When using an LSE on an airplane with a 12(14)V buss, the alternator's OV crowbar might be depended on to trip sooner than the LSE crowbar. Regards, Matt- > Thanks Bob for uncovering this. I had the same basic plan as you, using > a fuse off each of the two main batteries running up each side of the > fuselage to the two LSEIII's. > > I think knowing this now I will use a slightly larger fuse off the > battery, say 15amp with the appropriate wire of course, and then use > breaker switches for the LSE's. My batteries are in the back and I > certainly don't want two separate, unprotected wires running up the > length of the fuselage. If it's an OV and not enough to blow the 15amp > fuses then I can reset the LSE's using the switch breakers. If it's > something else that blows the 15amp, probably won't make a difference at > that point as it's either a fried component or a shorted wire. Does > this sound like a workable solution to everyone? > > Michael > ________________________________ Message 4 _____________________________________ Time: 01:44:36 PM PST US From: "RV Builder (Michael Sausen)" Subject: RE: AeroElectric-List: Re: Z-14 with dual Lightspeed III and SD-8 Like I said, slightly larger fuse. :) Normal operation lists an LSEIII at 7.5AMP requirement with a 10Amp fuse. My reasoning is that doubling the initial fuse would allow the breaker to go first under normal circumstances. I do agree that a slo-blo type fuse would probably decrease the likeliness of the fuse blowing first. I would just assume deal with this back at the batteries but it's not practical to have the CB's back there with no easy way to reset when I'm flying alone troubleshooting an overly quiet engine. I could feed one LSE from the main bus and the second directly from a battery which would probably cover most circumstances. Michael -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Matt Prather Sent: Tuesday, February 03, 2009 2:50 PM Subject: RE: AeroElectric-List: Re: Z-14 with dual Lightspeed III and SD-8 I suspect such series protection will always blow the fuse and not the breaker - if they both have the same rating. The time constant for blowing most standard breakers is much slower than for fuses. You might be able to upsize the wiring and fuse and get something to work - by operating the fuse at a much smaller percentage of it's fault current rating than the breaker. You could also pick a device with a slower blow time than a normal ATC fuse. An MDL maybe? The behavior of the system might also depend on how "good" the short is that is presented by the LSE's internal crow bar. The peak current wouldn't likely be anywhere close to that of connecting copper straight across the battery terminals. The impedance of the crowbar comes into play. One question I can't remember being asked/answered is what voltage the LSE's crowbar is designed to trip at. I suspect it might be quite high as I think the systems are allowed to be run from a 24(28)V bus - the manual lists proper operation up to 35V. When using an LSE on an airplane with a 12(14)V buss, the alternator's OV crowbar might be depended on to trip sooner than the LSE crowbar. Regards, Matt- > Thanks Bob for uncovering this. I had the same basic plan as you, using > a fuse off each of the two main batteries running up each side of the > fuselage to the two LSEIII's. > > I think knowing this now I will use a slightly larger fuse off the > battery, say 15amp with the appropriate wire of course, and then use > breaker switches for the LSE's. My batteries are in the back and I > certainly don't want two separate, unprotected wires running up the > length of the fuselage. If it's an OV and not enough to blow the 15amp > fuses then I can reset the LSE's using the switch breakers. If it's > something else that blows the 15amp, probably won't make a difference at > that point as it's either a fried component or a shorted wire. Does > this sound like a workable solution to everyone? > > Michael > ________________________________ Message 5 _____________________________________ Time: 02:35:10 PM PST US From: "Hinde, Frank George (Corvallis)" Subject: RE: AeroElectric-List: Re: Z-14 with dual Lightspeed III and SD-8 Absolutely..Then ditch the mechanical fuel pump and put the electric pumps in the wingrrots. You now have a vapour lock proof fuel system that will run on just about anything, including ethanol. Slightly off topic but you'd be amazed at how many builders balk at two electric fuel pumps, but two EI's is perfectly acceptable. Frank RV7a..IFR All electric, fuel pumps included. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of RV Builder (Michael Sausen) Sent: Tuesday, February 03, 2009 1:42 PM Subject: RE: AeroElectric-List: Re: Z-14 with dual Lightspeed III and SD-8 --> Like I said, slightly larger fuse. :) Normal operation lists an LSEIII at 7.5AMP requirement with a 10Amp fuse. My reasoning is that doubling the initial fuse would allow the breaker to go first under normal circumstances. I do agree that a slo-blo type fuse would probably decrease the likeliness of the fuse blowing first. I would just assume deal with this back at the batteries but it's not practical to have the CB's back there with no easy way to reset when I'm flying alone troubleshooting an overly quiet engine. I could feed one LSE from the main bus and the second directly from a battery which would probably cover most circumstances. Michael ________________________________ Message 6 _____________________________________ Time: 02:53:53 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Z-14 with dual Lightspeed III and SD-8 At 11:26 AM 2/3/2009, you wrote: >I dont think I am fully understanding this discussion. Bob, perhaps >you could provide a simple summary of the issue and concerns here >for the less enlightened? There are a lot of folks out here with >single or dual lightspeed ignitions. Under what circumstances are they at risk? The roots of this discussion go back a lot of years and is not limited to any particular manufacturer's design goals. Let me see if I can give you a distilled down synopsis that moves toward focus on the specifics of Lightspeed ignition systems. History: Conventional wisdom for design and fabrication of electrical systems suggests we provide ship's accessories with power constrained within the boundaries cited numerous documents but they're all about the same. For our purposes, let's talk about Mil-Std-704. For details, use the search engine on my website and look for hits on "mil-std-704". A similar search term on the Matronics archives search engine will yield another discussion and data-set. In particular, you can get your own copy of this document at: http://www.aeroelectric.com/Reference_Docs/Mil-Specs/Mil-Std-704f.pdf On the accessory side, there's an equally large library of documents that speak to design goals for accessories. The TC aircraft industry is fond of RTCA DO-160. I can't post a copy of this document as the folks at RTCA are pretty protective of their work product. Again, use the search engine on my website and the Matronics archives to look up "DO-160". You can access an outline of the spirit and intent of DO-160 at: http://www.aeroelectric.com/articles/DO-160.pdf Irrespective of any words you read where the writer brushes off the simple-ideas offered in these documents, they have a long and rich history of successful product design, development and operation in both military and civilian certified aviation. I've made a good living by bench-marking my work- product and that of my associates against the design goals suggested therein. I've been guilty of plenty of screw-ups in 40+ years that have cost my employer some dollars and some customers some inconvenience. But mistakes of attention or understanding were never attributable to inadequacies of 160/704 used in concert to craft robust and reliable systems. This is why I've offered up these two documents as THE STARTING PLACE for every new design. OBAM aviation is blessed with the opportunity to develop and exploit a constellation of new ideas and products that promise to reduce weight, cost, complexity with increases in performance and safety. Best yet, these ideas can come into the marketplace unburdened by the regulatory, policy and procedural albatrosses that are dragging once great companies down into the tar-pits of economic and intellectual paralysis. Since my first visit to OSH in '86, I've been aware of dozens of exciting and useful ideas that should be explored and perhaps exploited in OBAM aviation. While listening to some starry-eyed entrepreneur's excited explanation of an idea, I was acutely aware of a lack of foundation in system integration basics. From that very first year, I've offered my services to any and all takers to help them craft input, output and power connections that will improve upon seamless integration with the rest of the airplane's accessories. To date, perhaps a half dozen folks have seen fit to take advantage of this offer. Only one required enough of my attention to justify billing them. I made this same offer to Klaus (and his competition!) on several occasions. I reminded them all that I'm aware of the intellectual property secrets of dozens of clients who do not perceive risks for having used my services. Nonetheless, for whatever reasons, very few folks have availed themselves of my offer. Current Events: Now comes a new revelation to the community that a popular product is fitted with crowbar ov protection. This raises a question as to perceived value for adding such a feature internal to a system accessory. NORMALLY . . . one designs an accessory assuming that the prospective customer/ system integrator is aware of and complies with the spirit and intent of 160/704. Further, given that engine operations depend on the function of at least one of two installed systems, what are the design goals that prevent BOTH systems from responding to the same OV event and shutting themselves down? Why would a designer believe that adding this feature adds value/safety to their product? Could it be a lack of faith in the customer/integrator's ability to comply with 160/704? This is a legitimate concern. My seminars are sprinkled liberally with folks who's professional skills have not trained them to think about these ideas. We can only guess at the thoughts and motivation for the case before us. The questions to be explored: (1) If the crowbar OV protection were left out, what is the product's ability to stand off Mil-Std-704 compliant transients. (2) If so, would it not be BETTER to tell the customer that their airplane's power generation system should be crafted to stay at or below those limits? If you buy a radio from King, Garmin, etc., this goes without asking or answering. (3) If not so, what if anything should be considered to make the product more robust? This is usually very easy. Power conditioning compliance taxes only a tiny portion of the total design and qualification time for clean-piece-of-paper designs. (4) Finally, if the product under discussion is not accompanied with detailed explanations of all features that influence in-flight operations, why not? The customer/system-integrator is severely limited in crafting a best-we-know-how-to-do system if there are hidden or inadequately described features that affect performance. Even worse, overlooked or hidden features could become root cause in a hazardous scenario. This is why we do FMEA studies in groups with a goal of leaving no failure mode unconsidered. Path Forward: I will suggest that customers of the Lightspeed systems invite Klaus to join the AeroElectric- List for the purpose of sharing and sifting the constellation of simple-ideas from which we can craft the optimum solution. > Any suggested course of action? A lot of concern seems to have > been expressed without much direct input from the manufacturer. Exactly. I'll make the List members aware that not all of my past contacts with Klaus have been without tension. This is why I'll suggest that any participation by yours truly be carried out in this open forum. Klaus may choose not to participate here. It's important that he believe this is not a Star-Chamber being set up to abuse him. But if there's any forum that offers the highest probability of achieving understanding and crafting a successful solution . . . it's right here. As a first contribution to the solution I will assert that crafting a 704-compliant power source is NOT difficult. Bob . . . ________________________________ Message 7 _____________________________________ Time: 03:18:07 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Re: Z-14 with dual Lightspeed III and SD-8 At 03:41 PM 2/3/2009, you wrote: >Sausen)" > > Like I said, slightly larger fuse. :) Normal operation lists an > LSEIII at 7.5AMP requirement with a 10Amp fuse. My reasoning is > that doubling the initial fuse would allow the breaker to go first > under normal circumstances. I do agree that a slo-blo type fuse > would probably decrease the likeliness of the fuse blowing first. The fuse would need to be a LOT bigger. Crow-baring a 5A breaker would open a 20-30A up-stream fuse. This is because the I(square)*R time constant for opening a breaker is MUCH larger than for fuses of the same size. You can easily do this experiment for your self. Go out to your car's battery and hook an in-line fuse holder in series with a 5A breaker. Put about 5 feet of 20AWG wire in the loop too to limit max current. Connect this combination across your car battery and see how large the fuse has to be to stay closed while the breaker trips. This is why we have fusible links upstream of crowbar ov protection breakers in all the Z-figures. > I would just assume deal with this back at the batteries but it's > not practical to have the CB's back there with no easy way to reset > when I'm flying alone troubleshooting an overly quiet engine. I > could feed one LSE from the main bus and the second directly from a > battery which would probably cover most circumstances. The big band-aid is to install a separate high current relay to the battery through a LARGE in line fuse . . . probably 30A. Run 14AWG wire from the relay up to the panel mounted 5A breaker. Continue on with what-ever wire is called out to continue on to the ignition system. Now you need switches to control right and left ignition system relays at the battery. See: http://aeroelectric.com/Pictures/Schematics/Battery_Feed_for_Ignition.pdf This approach could be blessed in a TC aircraft as providing circuit protection commensurate with wire sizes AND making the system max-cold when the switches are OFF. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 8 _____________________________________ Time: 04:51:05 PM PST US From: "RV Builder (Michael Sausen)" Subject: RE: AeroElectric-List: Re: Z-14 with dual Lightspeed III and SD-8 Hmm, not a big fan of replacing one failure mode with another. I see a relay as being a bit of a step back and probably more likely to fail than to see an OV event. Maybe something as simple as using a 15amp breaker instead of a fuse would be less complex and eliminate the problem of a fuse blowing faster than a breaker, albeit more expensive. Michael -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Tuesday, February 03, 2009 5:16 PM Subject: RE: AeroElectric-List: Re: Z-14 with dual Lightspeed III and SD-8 At 03:41 PM 2/3/2009, you wrote: >Sausen)" > > Like I said, slightly larger fuse. :) Normal operation lists an > LSEIII at 7.5AMP requirement with a 10Amp fuse. My reasoning is > that doubling the initial fuse would allow the breaker to go first > under normal circumstances. I do agree that a slo-blo type fuse > would probably decrease the likeliness of the fuse blowing first. The fuse would need to be a LOT bigger. Crow-baring a 5A breaker would open a 20-30A up-stream fuse. This is because the I(square)*R time constant for opening a breaker is MUCH larger than for fuses of the same size. You can easily do this experiment for your self. Go out to your car's battery and hook an in-line fuse holder in series with a 5A breaker. Put about 5 feet of 20AWG wire in the loop too to limit max current. Connect this combination across your car battery and see how large the fuse has to be to stay closed while the breaker trips. This is why we have fusible links upstream of crowbar ov protection breakers in all the Z-figures. > I would just assume deal with this back at the batteries but it's > not practical to have the CB's back there with no easy way to reset > when I'm flying alone troubleshooting an overly quiet engine. I > could feed one LSE from the main bus and the second directly from a > battery which would probably cover most circumstances. The big band-aid is to install a separate high current relay to the battery through a LARGE in line fuse . . . probably 30A. Run 14AWG wire from the relay up to the panel mounted 5A breaker. Continue on with what-ever wire is called out to continue on to the ignition system. Now you need switches to control right and left ignition system relays at the battery. See: http://aeroelectric.com/Pictures/Schematics/Battery_Feed_for_Ignition.pdf This approach could be blessed in a TC aircraft as providing circuit protection commensurate with wire sizes AND making the system max-cold when the switches are OFF. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 9 _____________________________________ Time: 05:26:51 PM PST US Subject: AeroElectric-List: Re: Z-14 with dual Lightspeed III and SD-8 From: "bcondrey" I actually don't have an issue with this behavior (crowbar design) as long as it's a published design feature. Lacking that, there's nothing providing any clues to somebody installing these units that use of a CB vs a fuse should be considered mandatory. Text from the LSE Plasma III install instructions section 2.6: When connecting the power supply, route the positive lead to a 5A pull-able circuit breaker and then to the battery plus terminal, bypassing any electrical buss or master solenoid. Refer to the Input Connector Diagram. At this point not having specifics about voltage level, duration, etc. that causes a crowbar event within the ignition is really just academic curiosity to me. Real point is that there is apparently a crowbar circuit internal to the units that is meant to trip a CB if overvoltage is detected (maybe also overtemp?) and using an inaccessible fuse instead of a CB is just flat unacceptable (to me). I haven't grounded the plane simply because I've got redundancy with a 12 volt Z-14 implementation with B&C alternators and regulators. Not sure if the regulators are faster than the Plasma III, but since the Plasma III will accept 28 volt power I suspect the 12 volt regulator would trip an offending alternator offline before the Plasma III crowbarred. Even if something went really wrong with an alternator/regulator and an ignition popped the fuse, I've still got a second, isolated system. I will however be reconfiguring the ignition power supply wiring in the next couple of months. I hope nobody interprets me being sour on LSE, I actually love the ignitions! Klaus can be a little difficult to deal with and I can also accept that. My purpose was simply to inform of a failure mode. Given that there are a lot of LSE ignitions in the field and a lot of those are being powered through, this can't be that big of a problem - except for the poor soul that has an overvoltage condition which then causes the big fan up front to stop. Bob Read this topic online here: http://forums.matronics.com/viewtopic.php?p=228385#228385 ________________________________ Message 10 ____________________________________ Time: 08:00:46 PM PST US Subject: Re: AeroElectric-List: Re: Z-14 with dual Lightspeed III and SD-8 From: Sam Hoskins I seem to remember that a CB was used, so you could easily disconnect the power from the always hot bus, for example, when performing maintenance. I once had a conversation with Klaus about some problems I was having durin g installation and told him I took power off a bus. He was adamant that I follow the installation instructions and take power directly off the battery. It ultimately turned that my problem was caused by too much clearance between the Hall sensor and the rotating magnets. Sam www.samhoskins.blogspot.com On Tue, Feb 3, 2009 at 7:24 PM, bcondrey wrote : > bob.condrey@baesystems.com> > > I actually don't have an issue with this behavior (crowbar design) as lon g > as it's a published design feature. Lacking that, there's nothing provid ing > any clues to somebody installing these units that use of a CB vs a fuse > should be considered mandatory. > > Text from the LSE Plasma III install instructions section 2.6: > - When connecting the power supply, route the positive lead to a 5A > pull-able circuit breaker and then to the battery plus terminal, bypassin g > any electrical buss or master solenoid. Refer to the Input Connector > Diagram. > > At this point not having specifics about voltage level, duration, etc. th at > causes a crowbar event within the ignition is really just academic curios ity > to me. Real point is that there is apparently a crowbar circuit internal to > the units that is meant to trip a CB if overvoltage is detected (maybe al so > overtemp?) and using an inaccessible fuse instead of a CB is just flat > unacceptable (to me). I haven't grounded the plane simply because I've g ot > redundancy with a 12 volt Z-14 implementation with B&C alternators and > regulators. Not sure if the regulators are faster than the Plasma III, b ut > since the Plasma III will accept 28 volt power I suspect the 12 volt > regulator would trip an offending alternator offline before the Plasma II I > crowbarred. Even if something went really wrong with an > alternator/regulator and an ignition popped the fuse, I've still got a > second, isolated system. I will however be reconfiguring the ignition po wer > supply wiring in the next couple of mont! > hs. > > I hope nobody interprets me being sour on LSE, I actually love the > ignitions! Klaus can be a little difficult to deal with and I can also > accept that. My purpose was simply to inform of a failure mode. Given t hat > there are a lot of LSE ignitions in the field and a lot of those are bein g > powered through, this can't be that big of a problem - except for the poo r > soul that has an overvoltage condition which then causes the big fan up > front to stop. > > Bob > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=228385#228385 > > =========== =========== =========== =========== > > ________________________________ Message 11 ____________________________________ Time: 08:10:42 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Re: Z-14 with dual Lightspeed III and SD-8 At 06:49 PM 2/3/2009, you wrote: >Sausen)" > > Hmm, not a big fan of replacing one failure mode with another. I > see a relay as being a bit of a step back and probably more likely > to fail than to see an OV event. Maybe something as simple as > using a 15amp breaker instead of a fuse would be less complex and > eliminate the problem of a fuse blowing faster than a breaker, > albeit more expensive. > >Michael The relay is only to observe the TC world convention for making wiring max-cold with the switches off. Given that the breaker requirement forces you to have a "bus" at the panel, then the feeder to that bus must be considerably "stiffer" than the energies required to trip the breaker. Without the relay the wire between battery and breaker is not crash-worthy by certified standards. If you wish to adopt other standards . . . You are exceedingly unlikely to experience a relay failure concurrent with any other failure on a single tank of fuel. Further, failure of one relay is backed up by the second system. I.e., risks of double ignition failure versus risk of an ov condition is much lower. Bob . . . ________________________________ Message 12 ____________________________________ Time: 08:53:18 PM PST US From: "Rob du Plooy" Subject: AeroElectric-List: Dual Plasma III and Z-13/8..needing 2 x batteries and C/B's...?(Was Bob Nuckolls' Z-14 with Dual...) Hoo-boy.... Thanks Bob and others for recommending Z13/8....happy to continue with your dwgs and single battery..... till I read about the Lightspeed manual stating at paragraph ..2.7.. Electrical System Requirements All Plasma CDI systems can be used with 12 or 24 volt electrical systems. Input voltages above 35 volts or reversed polarity will cause system damage. For this reason it is mandatory that all aircraft using Plasma CD Ignitions are equipped with over-voltage protection in their alternator charging system(s). Over-voltage is a requirement for certified aircraft. Power connection must be directly to the battery terminals to avoid voltage spikes and electrical noise. Aluminum should never be used as an electrical conductor for the Plasma CDI. Use only the supplied aircraft quality stranded wire. Electrical Operating Instructions Dual Systems only: If you have installed an aux battery per the LSE supplied drawing, monitor your voltmeter and do not switch to the aux battery until the supply voltage of the main battery is below 6.5 Volts or the engine is not running smoothly. After switching to the aux battery, your voltmeter will read the voltage remaining in your aux battery. Do not switch your main alternator breaker in flight to avoid potentially damaging voltage spikes. This does not apply to the alternator field breaker. And further at para.2.8A.... A. Power Supply - =B7 When connecting the power supply, route the positive lead to a pull-able breaker, 4-cyl systems use 5A ...., and then directly to the battery plus terminal, bypassing any electrical buss or master solenoid. Refer to the Input Connector Diagram & the Electrical Requirements section 2.7. See here..... http://www.lightspeedengineering.com/Manuals/CdiManual_PlasmaII_II+_III.h tm And then for Dual Plasma CDI, Klaus further recommends..... For Dual PLASMA CDI Installations, an auxiliary battery and dual ignition indicator lights are recommended. Please click here for an aux battery wiring diagram. See Figure 4 for the dual ignition indicator lights diagram: click here. See here for the AUX Batt Diagram..........http://www.lightspeedengineering.com/Manuals/PS_Diagram. htm How do I incorporate these- the 2 x "pullable" C/bs and 2 x batteries - within Z13/8...? Thanks, Robert ------------------------------------------------------------------------------------- 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.