---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 12/30/11: 13 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:34 AM - Re: Re: First Engine Start Problem (Robert L. Nuckolls, III) 2. 08:30 AM - Re: Re: First Engine Start Problem (Robert L. Nuckolls, III) 3. 10:55 AM - Re: Re: First Engine Start Problem (Bob McCallum) 4. 10:58 AM - Audio out for Aera 560 GPS? (Don Ingalls) 5. 02:10 PM - flashing landing lights. (bob noffs) 6. 03:04 PM - Re: flashing landing lights. (Bob McCallum) 7. 03:05 PM - Re: Re: First Engine Start Problem (Dan Billingsley) 8. 03:56 PM - Re: flashing landing lights. (earl_schroeder@juno.com) 9. 04:19 PM - Wiring Harness (Dan Sherburn) 10. 04:52 PM - Re: First Engine Start Problem (user9253) 11. 05:21 PM - Re: Re: First Engine Start Problem (Dan Billingsley) 12. 06:59 PM - Re: Wiring Harness (Jared Yates) 13. 07:17 PM - Re: Re: First Engine Start Problem (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 06:34:42 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: First Engine Start Problem At 09:45 PM 12/29/2011, you wrote: The diode being backwards was the reason the fusible link burned open. Part of the starter current was going through the E-Bus circuit. There is a saying that electricity takes the path of least resistance. Even though there is a big fat wire going from the battery to the starter, that path is not the least resistance for ALL of the current. Some of the current will find it easier to take parallel paths. An analogy is highway traffic. Most cars will take the multi-lane expressway. But when traffic is very heavy and slows down, some cars will take side streets. For them it is the path of least resistance. Your lighting circuit could be moved to the main bus. The E-Bus should handle 5 amps OK. The additional 2 amps while transmitting is of short duration and should not burn open the fusible link. I will not be offended if Bob or anyone corrects me. You are right on my friend. I will remind readers that the e-bus (while once erroneously called an "essential bus") was crafted for the purpose of keeping an alternator- out event from becoming an emergency. Hence, it was re-named the Endurance Bus. Successful and worry free application of the e-bus is dependent upon TWO things. (1) Knowing the minimum amount of energy stored in the battery and (2) knowing how many hours of flight are possible while being a good student of Energy Economics. One of my most cherished teachers, Thomas Sowell told me that economics is the study of scarce resources for which there are multiple uses. In this case, the scarce resource is watt-seconds of electrical energy available to run JUST the electro- whizzies most useful or en route operations. Once you have the airport of intended destination in sight, the scarcity of watt-seconds disappears. My personal design goal for sizing and powering the e-bus is to have more hours of en-route ops available from the electro- whizzies than I have fuel aboard. Everybody plans for there to be enough fuel for the mission leg . . . it seems that having a properly crafted e-bus is a good move for making a dead alternator a maintenance event as opposed to an emergency. Some years ago at Oshkosh, I suggested in one of my forums that system reliability is achieved when you can deal with any single failure without breaking a sweat. Since the people who own the airplanes I rent would not let me re-arrange their bus structures, my personal e-bus is powered by alkaline cells. http://tinyurl.com/4xjhgly Whether I'm flying a J-3 or an A-36, I can confidently get where I want to go on an exceedingly austere budget of self contained watt-seconds. I recommend that the builder craft a Plan-B for alternator out-ops that includes periodic capacity checks to make sure that their battery's current state will carry e-bus loads for the duration of their personal design goals. Whether that's 1 hour or duration of fuel aboard is your decision. But knowing WHAT it is an maintaining it is essential to the no-sweat management of an alternator-out event. You can obviously have more than necessary goodies on the e-bus . . . as long as they have ON-OFF switches. The goal is to have a plan for load-shedding in place that re-configures energy consumption to meet electrical endurance design goals. Over the years I've studied many "Dark-n- Stormy Night" stories and deduced that most if not all would never have been written had the pilot/author had (1) understanding and (2) an artfully crafted and maintained Plan-B. Bob . . . ________________________________ Message 2 _____________________________________ Time: 08:30:21 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: First Engine Start Problem At 08:33 PM 12/29/2011, you wrote: >Just got back from the airport and found the following: >1.I took the ammeter reading across the Alternate switch (with the >Master switch off). I was reading at 5.2 A with everything on and >that was without keying the mic for transmission. I assume that >would bump it up even more (didn't get a chance to try that). Okay, how does 5.2A fit into your Plan-B? >2. The Diode between the two buses WAS backwards. I changed it and >now my panel lights up when the Master switch is on. Would this have >had any bearing on why my fuseable link burned or do you think I >need to move some things to the Main bus? The components I have on >the E-bus are as follows: >Dynon D100, Garmin 396, EIS (engine monitor), SL40 radio, >Transponder, LED Becon and tail position light, Intercom, HZ Stab >trim servo. I don't have wing tip position/Nav lights yet but can >probably put them on the main bus along with the other lights when I >get them. The other thing I was toying with is moving the D-100 and >the 396 over as they both have back-up batteries Thoughts or >suggestions welcome. See my earlier posting about Plan-B. You don't necessarily need to move anything. But you SHOULD have a check-list driven plan of action for responding to a low-voltage warning light. 5.2A may not be the Plan-B number. The lower you can make it, the more secure you are in dealing with an alternator failure. Bob . . . ________________________________ Message 3 _____________________________________ Time: 10:55:58 AM PST US From: Bob McCallum Subject: RE: AeroElectric-List: Re: First Engine Start Problem Dan; While the reversed diode is definitely the cause of the fused fusible link (in combination with having the alternate feed switch on) and installing the diode correctly will prevent the link failing in the future, (your loads are well within what the link will handle) this might also be an indication that there is a higher than desirable resistance in the "fat wire" circuit. Normally the resistance of the large wires and their connections is very very low and they should present the most attractive path for the starter current. However if one of the connections in this circuit is displaying relatively high resistance due to being loose or dirty or???? Then the parallel path through the miswired e-buss circuit might become more attractive and draw an unusually larger percentage of the starter current aggravating the scenario explained by Joe. It might be worth a simple voltage drop test across the fat wire circuit components while cranking to see if there are any joints or portions of that circuit displaying higher than normal resistance. If wired precisely per Z-16 then the likely source for the high resistance, if it exists, would be one of the connections to the battery contactor or the contactor itself. The other possibility of course is that if you tried to crank the engine with the reversed diode, the alternate feed "on" and the master switch "off" then full cranking current was attempting to pass through your fusible link and "poof". Correctly installing the diode absolutely cures this possibility as well. Bob McC > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list- > server@matronics.com] On Behalf Of user9253 > Sent: Thursday, December 29, 2011 10:46 PM > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: Re: First Engine Start Problem > > > The diode being backwards was the reason the fusible link burned open. Part of the > starter current was going through the E-Bus circuit. There is a saying that electricity > takes the path of least resistance. Even though there is a big fat wire going from the > battery to the starter, that path is not the least resistance for ALL of the current. > Some of the current will find it easier to take parallel paths. An analogy is highway > traffic. Most cars will take the multi-lane expressway. But when traffic is very heavy > and slows down, some cars will take side streets. For them it is the path of least > resistance. > Your lighting circuit could be moved to the main bus. The E-Bus should handle 5 > amps OK. The additional 2 amps while transmitting is of short duration and should > not burn open the fusible link. I will not be offended if Bob or anyone corrects me. > Joe > > -------- > Joe Gores > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=361963#361963 > > > > > > > > _- > ==================================================== > ====== > _- > ==================================================== > ====== > _- > ==================================================== > ====== > _- > ==================================================== > ====== > _- > ==================================================== > ====== > > ________________________________ Message 4 _____________________________________ Time: 10:58:02 AM PST US Subject: AeroElectric-List: Audio out for Aera 560 GPS? From: Don Ingalls I'm looking for a sanity check on wiring a Garmin Aera 560 into my panel. My main objective is to get the GPS alerts to my headset. The Garmin documentation for the aviation bare wire mount was not helpful and essentially just says the audio out is: White (Audio Right), Brown (Audio Left) and Green (Audio Common) . Reference http://www8.garmin.com/manuals/aera500_PilotsGuide.pdf page 140 of the manual. Writing and calling Garmin did not prove fruitful as they say the audio out is for a "Marine Sounder" and that I should use the Audio Out stereo out on the side and not these three wires for proper XM music quality. I could find no other documentation. I also have a Sigtronics SPA-4S so in my quest for information I called them. The person at Sigtronics was very helpful and the summary of his advice was this: Connect a 220 ohm 0.25 W resistor to the audio right, another to audio left and then connect the other ends of the resistor together and splice into the J1 connector, Blue wire from radio headphone audio. This should give the proper priority to the GPS audio warnings (Terrain, Airspace, etc.). Adjust the resistor down if needed to increase GPS volume but this will also decrease volume from the radio. Reference diagram at http://www.sigtronics.com/pdf/air_pdf/SPA-4S_King_KY-97A_Inst.pdf So, my questions are; Does this strategy and resistor value sound right to convert this to a mono output? I'm assuming I still connect the Audio common, green wire of the GPS to ground, correct? If I want XM radio, then I would plug into the audio out stereo port on the side of the GPS to the Music Input jack that is wired into intercom. Correct? Any additional guidance or advice would be greatly appreciated! Don Ingalls ________________________________ Message 5 _____________________________________ Time: 02:10:08 PM PST US Subject: AeroElectric-List: flashing landing lights. From: bob noffs are there any bad effects to my elect. system if i install 2 small halide ''landing lights'' of 55 watts each and wire in 2 automotive flashers so i can use them flashing in the pattern for traffic avoidance..i have a jab 3300. bob noffs ________________________________ Message 6 _____________________________________ Time: 03:04:32 PM PST US From: Bob McCallum Subject: RE: AeroElectric-List: flashing landing lights. No, no adverse effects, but it's more effective if you use one flasher which alternates the lights rather than two flashers which would have the lights completely random. Suitable flashers are readily available from automotive parts stores and are typically used for such things as the alternating lights on school buses. "Wigwag" flashers are also available from any number of aviation sources. Go to the archives and search "wigwag" for several discussions on the topic. Bob McC _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of bob noffs Sent: Friday, December 30, 2011 5:05 PM Subject: AeroElectric-List: flashing landing lights. are there any bad effects to my elect. system if i install 2 small halide ''landing lights'' of 55 watts each and wire in 2 automotive flashers so i can use them flashing in the pattern for traffic avoidance..i have a jab 3300. bob noffs ________________________________ Message 7 _____________________________________ Time: 03:05:12 PM PST US From: Dan Billingsley Subject: Re: AeroElectric-List: Re: First Engine Start Problem I would like to thank all who responded to the issue at hand. I learned many things here, most importantly, how my electrical system is designed to work along with howI need to work. In the world of reading schematics and interpreting how they are to be used...I am STILL learning. My assumptions believing the E-switch was to be on sifted back to when I was flying the rented 172 and of course, there IS a switch that needed to be on for the radios, intercom, Etc... So much for the ASSuming. I was quite surprised when I found my diode in backwards as I am usually quite anal when building circuits, yet, I am now actually glad it happened in this manner as I would have been utilizing my system incorrectly. Thank you Joe for bringing up the possibility of the reversed diode...Spot On Sir. And Thanks again to Bob N. for pointing my brain cell (the one that is still working) to the possible overloading as well as taking a better look at what my Plan_B needs to look like. I will most likely move any lights over to the Main, but more importantly take a close look at how much time a given instrument (as well as combined gizmos) should take me. I will most likely leave my D-100, GPS and the radio where they sit. knowing I can turn one or two off to get my butt to the safety line will always be there. I Wish everyone a Happy New Year! Dan ________________________________ From: "Robert L. Nuckolls, III" Sent: Fri, December 30, 2011 9:26:38 AM Subject: Re: AeroElectric-List: Re: First Engine Start Problem At 08:33 PM 12/29/2011, you wrote: > Just got back from the airport and found the following: > 1.I took the ammeter reading across the Alternate switch (with the Master >switch off). I was reading at 5.2 A with everything on and that was without >keying the mic for transmission. I assume that would bump it up even more >(didn't get a chance to try that). Okay, how does 5.2A fit into your Plan-B? > 2. The Diode between the two buses WAS backwards. I changed it and now my panel >lights up when the Master switch is on. Would this have had any bearing on why >my fuseable link burned or do you think I need to move some things to the Main >bus? The components I have on the E-bus are as follows: > Dynon D100, Garmin 396, EIS (engine monitor), SL40 radio, Transponder, LED >Becon and tail position light, Intercom, HZ Stab trim servo. I don't have wing >tip position/Nav lights yet but can probably put them on the main bus along with >the other lights when I get them. The other thing I was toying with is moving >the D-100 and the 396 over as they both have back-up batteries Thoughts or >suggestions welcome. See my earlier posting about Plan-B. You don't necessarily need to move anything. But you SHOULD have a check-list driven plan of action for responding to a low-voltage warning light. 5.2A may not be the Plan-B number. The lower you can make it, the more secure you are in dealing with an alternator failure. Bob . . . ________________________________ Message 8 _____________________________________ Time: 03:56:26 PM PST US From: "earl_schroeder@juno.com" Subject: Re: AeroElectric-List: flashing landing lights. I'm using two 55 watt 'halide' (one on each landing gear) and using heav y duty truck flashers seem to work OK. EE ---------- Original Message ---------- From: bob noffs Subject: AeroElectric-List: flashing landing lights. are there any bad effects to my elect. system if i install 2 small halid e ''landing lights'' of 55 watts each and wire in 2 automotive flashers so i can use��them flashing in the pattern for traffic avo idance..i have a jab 3300.� ________________________________ Message 9 _____________________________________ Time: 04:19:41 PM PST US From: "Dan Sherburn" Subject: AeroElectric-List: Wiring Harness What are thoughts on creating the electrical wiring harness? I've attached the embrionic schematic (lot's of final design, editing and cleanup to do) just to convey the simplicity of my Zenith CH750 electrical system. Specifically, should I: 1.. mock-up (chalk) an outline of the plane, run the requisite wires, label and bundle them (using expandable sleeving or spiral wrap)? ie. complete an entire harness.... 2.. or, just run wires one at a time and tie wrap and sheath with an expandable sleeve or spiral wrap them once all of the circuits are wired and tested? 3.. what's best to use in as far as a spiral wrap or expandable sleeve? I've heard the term "snakeskin" used.... Much of the drawing/design/symbols in the attached was gleaned from the AeroElectric Connection.... Regards, Dan Sherburn ________________________________ Message 10 ____________________________________ Time: 04:52:18 PM PST US Subject: AeroElectric-List: Re: First Engine Start Problem From: "user9253" > The guys that were working with me asked me why that link was there...I did not have a good answer for them. . . .So...I am now reluctant to put another fuseable link in place . . . Without a fusible link and in the event of a short circuit or heavy overload, the full length of the circuit wire could become red hot or even white hot. Think of a fusible link as a robust, slow blowing, fuse. Having a fusible link will ensure that heat and smoke from a circuit fault will occur at a known safe location rather than at a random location in the wire harness. The diode might have been conducting more current than it was designed to carry. A simple test will confirm that it is still blocking reverse current. With the master switch off and the E-Bus switch on, the main bus should not be energized and anything connected to it should not be powered. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=362053#362053 ________________________________ Message 11 ____________________________________ Time: 05:21:16 PM PST US From: Dan Billingsley Subject: Re: AeroElectric-List: Re: First Engine Start Problem Now that I know why and how the fuseable link burned, I will be replacing it. I have already called my buddies and gave them the answer I was (at the time) unsure about. Joe, I'm glad you addressed the integrity of the diode. It re-affirmed my thoughts as well and I have already decided to replace it (cheap insurance). Thanks again for the assistance. Dan ________________________________ From: user9253 Sent: Fri, December 30, 2011 5:48:09 PM Subject: AeroElectric-List: Re: First Engine Start Problem > The guys that were working with me asked me why that link was there...I did not >have a good answer for them. . . .So...I am now reluctant to put another >fuseable link in place . . . Without a fusible link and in the event of a short circuit or heavy overload, the full length of the circuit wire could become red hot or even white hot. Think of a fusible link as a robust, slow blowing, fuse. Having a fusible link will ensure that heat and smoke from a circuit fault will occur at a known safe location rather than at a random location in the wire harness. The diode might have been conducting more current than it was designed to carry. A simple test will confirm that it is still blocking reverse current. With the master switch off and the E-Bus switch on, the main bus should not be energized and anything connected to it should not be powered. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=362053#362053 ________________________________ Message 12 ____________________________________ Time: 06:59:55 PM PST US Subject: Re: AeroElectric-List: Wiring Harness From: Jared Yates In my case I ran the wires one at a time, building a bundle with wrapping th read ties as necessary to keep the wires parallel. I doubt you would save an y time by trying to make a separate harness like the production companies us e, unless you are going to start producing them. On Dec 30, 2011, at 19:16, "Dan Sherburn" wrote: > What are thoughts on creating the electrical wiring harness? I've attached the embrionic schematic (lot's of final design, editing and cleanup to do) j ust to convey the simplicity of my Zenith CH750 electrical system. > Specifically, should I: > mock-up (chalk) an outline of the plane, run the requisite wires, label a nd bundle them (using expandable sleeving or spiral wrap)? ie. complete an e ntire harness.... > or, just run wires one at a time and tie wrap and sheath with an expandabl e sleeve or spiral wrap them once all of the circuits are wired and tested? > what's best to use in as far as a spiral wrap or expandable sleeve? I've h eard the term "snakeskin" used.... > Much of the drawing/design/symbols in the attached was gleaned from the Ae roElectric Connection.... > > Regards, > Dan Sherburn > > > > ________________________________ Message 13 ____________________________________ Time: 07:17:25 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: First Engine Start Problem At 06:48 PM 12/30/2011, you wrote: > The guys that were working with me asked me why that link was there...I did not have a good answer for them. . . .So...I > am now reluctant to put another fuseable link in place . . . Without a fusible link and in the event of a short circuit or heavy overload, the full length of the circuit wire could become red hot or even white hot. Think of a fusible link as a robust, slow blowing, fuse. Having a fusible link will ensure that heat and smoke from a circuit fault will occur at a known safe location rather than at a random location in the wire harness. Which is the function of all protective devices for wire. Fuses are very fast comparted to circuit breakers. Circuit breakers are very fast compared to 'current limiters' which are manufactured versions of fusible links. See: http://aeroelectric.com/Mfgr_Data/Fuses_and_Current_Limiters/Bussman/ANL_Specs.pdf Note that an ANL35 will carry 80 amps indefinitely at room temperature. Say what???? A 35 amp fuse needs to be operated at no more than 75% of rating to avoid long term weakening of the fusible element. The difference in these two devices is their application. A line fault where a fuse is wired upstream of a breaker will probably open a fuse several times the size of the breaker. Current limiters (and fusible links) are used upstream of both fuses and breakers in cars and airplanes. They have VERY long time constants compared to the downstream devices . . . yet they provide the same 'weak link in chain' that guarantees a predictable failure. The provide an orderly failure location for a faulted feeder that is robust enough not to compromise the performance of downstream protection. This is exactly what YOUR fusible link did. Had it not been installed, you would have probably overheated if not smoked the protected wire . . . possibly damaging other wires in the bundle. If you wanted to put a 20A, in-line fuse holder in its place, that would be fine too as long as you don't have BREAKERS downstream. I'm working an accident case right now that involved poor choice and placement of fuses and breakers combined with an architecture that offered several single points of failure for all ignition to the engine . . . not good. We'll discuss it in detail once the dust settles on the legal tug-of-war. The lesson here is that the 'rating' of a fuse, breaker, limiter, or link is only roughly tied to performance. Until you trade of TIME to OPERATE values, you don't know the whole story. The diode might have been conducting more current than it was designed to carry. A simple test will confirm that it is still blocking reverse current. With the master switch off and the E-Bus switch on, the main bus should not be energized and anything connected to it should not be powered. Replacing it is a good idea. It's easier to simply install a new one than it is to test the old one for changes in performance due to the fault condition. 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