AeroElectric-List Digest Archive

Thu 08/10/17


Total Messages Posted: 17



Today's Message Index:
----------------------
 
     1. 03:20 AM - Re: Re: Fuse Blocks (GTH)
     2. 08:09 AM - Another Alternator Question (kearney)
     3. 08:20 AM - Re: Another Alternator Question (Charlie England)
     4. 08:32 AM - Re: Re: Fuse Blocks (Charles Kuss)
     5. 08:43 AM - Re: Questions for the alternator mavens (Robert L. Nuckolls, III)
     6. 09:19 AM - Re: Another Alternator Question (kearney)
     7. 10:21 AM - Re: Questions for the alternator mavens (user9253)
     8. 11:01 AM - Re: Re: Another Alternator Question (Charlie England)
     9. 11:27 AM - Re: Another Alternator Question (kearney)
    10. 11:37 AM - Re: Questions for the alternator mavens (Sebastien)
    11. 11:40 AM - Re: Re: Questions for the alternator mavens (Sebastien)
    12. 11:52 AM - Re: Re: Questions for the alternator mavens (Edward Gilroy)
    13. 12:56 PM - Re: Fuse Blocks (user9253)
    14. 01:22 PM - Re: Another Alternator Question (Robert L. Nuckolls, III)
    15. 04:31 PM - Re: Another Alternator Question (user9253)
    16. 07:03 PM - Re: Another Alternator Question (kearney)
    17. 08:19 PM - Re: Another Alternator Question (user9253)
 
 
 


Message 1


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    Time: 03:20:44 AM PST US
    From: GTH <gilles.thesee@free.fr>
    Subject: Re: Fuse Blocks
    Le 09/08/2017 21:40, user9253 a crit : > > So I made my own fuse block using a PCB and fuse clips. Search the web for "Keystone 3522". > My fuse holder has 18 fuses, 2 of which are spares. The wires exit straight out the back. Hi Joe, Most interesting, congratulations ! I wish I could see the back of your fuseblock ! What did you use for the bus itself ? Metal strip, solid wire ? Did you use Faston tabs to attach the wires ? -- Best regards, Gilles http://contrails.free.fr http://lapierre.skunkworks.free.fr


    Message 2


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    Time: 08:09:14 AM PST US
    Subject: Another Alternator Question
    From: "kearney" <kearney@shaw.ca>
    Bob et Al I have been reading the AEC trying to get smart(er) on alternators and failure modes etc. The "Z" diagrams are quite informative. As the -10 I am building will have EFI/EI I want to make sure that I understand what happens when electrical things fail. The one failure I am unsure about is the battery contactor. For example, if I am trundling along at altitude with all my electro-goodies powered up and the battery contactor fails, what happens (assuming I am wired in accordance with the Z13/8 diagram). I know that the OV protection will deal with voltage spikes. Is there anything else to be concerned about such as a current spike (if it exists)? Inquiring minds need to know. Les Read this topic online here: http://forums.matronics.com/viewtopic.php?p=471702#471702


    Message 3


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    Time: 08:20:45 AM PST US
    Subject: Re: Another Alternator Question
    From: Charlie England <ceengland7@gmail.com>
    On 8/10/2017 10:08 AM, kearney wrote: > > Bob et Al > > I have been reading the AEC trying to get smart(er) on alternators and failure modes etc. The "Z" diagrams are quite informative. > > As the -10 I am building will have EFI/EI I want to make sure that I understand what happens when electrical things fail. The one failure I am unsure about is the battery contactor. > > For example, if I am trundling along at altitude with all my electro-goodies powered up and the battery contactor fails, what happens (assuming I am wired in accordance with the Z13/8 diagram). I know that the OV protection will deal with voltage spikes. Is there anything else to be concerned about such as a current spike (if it exists)? > Inquiring minds need to know. > > Les > You really can't have a current spike, unless you have either a voltage spike or a resistance drop (load increase). --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus


    Message 4


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    Time: 08:32:47 AM PST US
    From: Charles Kuss <chaskuss@yahoo.com>
    Subject: Re: Fuse Blocks
    I purchased the fuse blocks linked below. The electrical connections are mounted from the rear. The blocks also come with a plastic cover to shield the fuses. This comes in very handy if you decide to mount the fuse block horizontally. I can supply photos of how I mounted them in my RV-8A See http://www.mihdirect.biz/ Charlie -------------------------------------------- On Thu, 8/10/17, GTH <gilles.thesee@free.fr> wrote: Subject: Re: AeroElectric-List: Re: Fuse Blocks To: aeroelectric-list@matronics.com Date: Thursday, August 10, 2017, 6:20 AM GTH <gilles.thesee@free.fr> Le 09/08/2017 21:40, user9253 a crit : > --> AeroElectric-List message posted by: "user9253" <fransew@gmail.com> > > So I made my own fuse block using a PCB and fuse clips. Search the web for "Keystone 3522". > My fuse holder has 18 fuses, 2 of which are spares. The wires exit straight out the back. Hi Joe, Most interesting, congratulations ! I wish I could see the back of your fuseblock ! What did you use for the bus itself ? Metal strip, solid wire ? Did you use Faston tabs to attach the wires ? -- Best regards, Gilles http://contrails.free.fr http://lapierre.skunkworks.free.fr The AeroElectric-List Email Forum - Navigator to browse List Un/Subscription, 7-Day Browse, Chat, FAQ, - MATRONICS WEB FORUMS - via the Web Forums! - NEW MATRONICS LIST WIKI - Email List Wiki! - List Contribution Web Site - support! -Matt Dralle, List Admin.


    Message 5


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    Time: 08:43:44 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Questions for the alternator mavens
    At 10:19 PM 8/9/2017, you wrote: >The electrical system in my aircraft is definitely optional. While I >would like to have a full IFR and ice capable aircraft with weather >radar and 2 engines, what I have is a day VFR BD-4. If the >conditions require a panel, I'm borrowing someone else's aircraft :). > >The battery did manage to start the engine which I was not >expecting. I left the digital voltmeter plugged in for the flight >and voltage went to 14.15 again and drifted down to 14.01 by the >time I shut down 45 minutes later. Okay, it would be a useful experiment to change out the regulator. It would be nice to find one that runs a bit higher voltage over the range of production variation. > No amount of load available (fuel pump, pitot heat, and all > lights) had any effect on the bus voltage, even momentary. Turning > the battery off momentarily did fluctuate the voltage but not more than 0.2. Which suggests your regulator is functioning just fine . . . at the low side of production tolerance. > Ammeter not showing any charge going into the battery. Do we presume correctly that you have a minus-zero-plus battery ammeter? > Battery voltage 15 minutes after shutdown was 12.76. Was this measured at the battery terminals with the master switch OFF? So I think the battery is completely toast and the charging system is fine in general and fine specifically for this battery. I am going to order one of those regulators as a spare because at that price, why not? I ordered the battery from Aircraft Spruce so I'm going to try to get warranty tomorrow but we'll see. Agreed . . . > > >Engine is O-320 160HP with Sky Tec NL starter and wood prop. I think your battery may be a bit light for your a/c. The SkyTec starters are permanent magnet with especially high inrush currents. There's a reason B&C stayed with the wound-field starter configuration as being kinder and gentler to the ship's battery without sacrificing cranking performance. Emacs! The PC680 is by far the Odyssey favorite for your size engine in OBAM aircraft. Half again better internal resistance hence more tolerant of SkyTec inrush currents. Bob . . .


    Message 6


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    Time: 09:19:50 AM PST US
    Subject: Re: Another Alternator Question
    From: "kearney" <kearney@shaw.ca>
    Hi Thanks for the the quick response. Unfortunately I don't understand what happens inside an alternator when it is instantly disconnected from the battery with the field still energized. Is a high current spike possible in such a situation and if so will if fry my toys? If this is a risk, how do I protect against it? Cheers Les Read this topic online here: http://forums.matronics.com/viewtopic.php?p=471710#471710


    Message 7


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    Time: 10:21:47 AM PST US
    Subject: Re: Questions for the alternator mavens
    From: "user9253" <fransew@gmail.com>
    Sebastien, I had posted previously that there was something wrong with the charging system. That was based on your post saying that the alternator voltage was low, between 13 to 13.5 Now you are saying that the charging voltage is normal. So now I think that either the battery is bad or there is bad battery connection. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=471713#471713


    Message 8


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    Time: 11:01:55 AM PST US
    Subject: Re: Another Alternator Question
    From: Charlie England <ceengland7@gmail.com>
    On 8/10/2017 11:19 AM, kearney wrote: > > Hi > > Thanks for the the quick response. Unfortunately I don't understand what happens inside an alternator when it is instantly disconnected from the battery with the field still energized. Is a high current spike possible in such a situation and if so will if fry my toys? If this is a risk, how do I protect against it? > > Cheers > > Les > Which architecture are we discussing? Are you talking about your master contactor? If so, if it disconnects, the field voltage should drop at the same time, collapsing the alternator's output. In any case, unless the battery is severely discharged (not a good starting point for a flight) & is drawing heavily on the alternator at the time the 'battery contactor' drops out, there should be minimal variation in alternator load and minimal variation in it's output. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus


    Message 9


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    Time: 11:27:24 AM PST US
    Subject: Re: Another Alternator Question
    From: "kearney" <kearney@shaw.ca>
    Hi Again My question was generic and not based directly on any of the "Z" diagrams. I just want to know what happens when things go sideways. Assume a simple situation, battery, contactor and alternator servicing a 20a load on a simple bus. Assume that there is appropriate OV protection per AEC. What happens if the battery contactor fails thereby disconnecting the battery from the system. For clarity, assume the alternator field is still energized. And everything was working fine prior to the disconnect. Cheers Les Read this topic online here: http://forums.matronics.com/viewtopic.php?p=471715#471715


    Message 10


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    Time: 11:37:11 AM PST US
    From: Sebastien <cluros@gmail.com>
    Subject: Re: Questions for the alternator mavens
    Bob, when deciding on a battery last year the 680 looked like a better choic e but the 545 was within the requirements that I could find. I cannot rememb er exactly where I looked but I think it was from generic lycoming manuals a nd I figured if it's within spec with a legacy starter it could only be bett er with a modern lightweight one. The smaller and lighter size was much easi er to install so that's what I went with. It sounds like you may think that t his failure could have something to do with how hard the battery is working. Do you think I have chosen too small a battery and a new one will have a si milar life span? Ammeter is indeed minus-zero-plus. Normal is within a needle width of zero, a fter a hard start perhaps as high as 30A initially. I should have measured the final voltage at the battery but it was too tempt ing with the digital voltmeter already plugged into the bus to just flip the master on. When my wife is hungry the rest of the world doesn't seem to exi st. So that 12.76V was with the master solenoid on but no load other than fu el gauges. Thank you for your expertise, Sebastien > On Aug 10, 2017, at 08:43, Robert L. Nuckolls, III <nuckolls.bob@aeroelect ric.com> wrote: > > At 10:19 PM 8/9/2017, you wrote: >> The electrical system in my aircraft is definitely optional. While I woul d like to have a full IFR and ice capable aircraft with weather radar and 2 e ngines, what I have is a day VFR BD-4. If the conditions require a panel, I' m borrowing someone else's aircraft :). >> >> The battery did manage to start the engine which I was not expecting. I l eft the digital voltmeter plugged in for the flight and voltage went to 14.1 5 again and drifted down to 14.01 by the time I shut down 45 minutes later. > > Okay, it would be a useful experiment to change > out the regulator. It would be nice to find one > that runs a bit higher voltage over the range > of production variation. > >> No amount of load available (fuel pump, pitot heat, and all lights) had a ny effect on the bus voltage, even momentary. Turning the battery off moment arily did fluctuate the voltage but not more than 0.2. > > Which suggests your regulator is functioning just > fine . . . at the low side of production tolerance. > >> Ammeter not showing any charge going into the battery. > > Do we presume correctly that you have a minus-zero-plus > battery ammeter? > >> Battery voltage 15 minutes after shutdown was 12.76. > > Was this measured at the battery terminals with > the master switch OFF? > > > So I think the battery is completely toast and the charging system is fine in general and fine specifically for this battery. I am going to order one o f those regulators as a spare because at that price, why not? I ordered the b attery from Aircraft Spruce so I'm going to try to get warranty tomorrow but we'll see. > > Agreed . . . > >> >> >> Engine is O-320 160HP with Sky Tec NL starter and wood prop. > > I think your battery may be a bit light for your > a/c. The SkyTec starters are permanent magnet with > especially high inrush currents. There's a reason > B&C stayed with the wound-field starter configuration > as being kinder and gentler to the ship's battery without > sacrificing cranking performance. > > > > The PC680 is by far the Odyssey favorite for your > size engine in OBAM aircraft. Half again better internal > resistance hence more tolerant of SkyTec inrush > currents. > > > Bob . . .


    Message 11


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    Time: 11:40:13 AM PST US
    From: Sebastien <cluros@gmail.com>
    Subject: Re: Questions for the alternator mavens
    Thank you Joe. It is indeed difficult to troubleshoot without good data. I have been meaning to scrap that analog voltmeter for a very long time but haven't found a suitable (inexpensive) alternative yet. Sebastien > On Aug 10, 2017, at 10:21, user9253 <fransew@gmail.com> wrote: > > > Sebastien, I had posted previously that there was something wrong with the charging system. That was based on your post saying that the alternator voltage was low, between 13 to 13.5 > Now you are saying that the charging voltage is normal. So now I think that either the battery is bad or there is bad battery connection. > > -------- > Joe Gores > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=471713#471713 > > > > > > > > >


    Message 12


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    Time: 11:52:15 AM PST US
    From: Edward Gilroy <egilroy@gmail.com>
    Subject: Re: Questions for the alternator mavens
    Craigslist, I have scored several decent used Fluke DVMs for less than $75. One was $50 and brand new but that was a lady selling all her husbands tools just after throwing him out of the house!!! Lock your tools before fighting with the spouse!! Sent from my iPhone - Expect lots of typos!!! > On Aug 10, 2017, at 2:39 PM, Sebastien <cluros@gmail.com> wrote: > > > Thank you Joe. It is indeed difficult to troubleshoot without good data. I have been meaning to scrap that analog voltmeter for a very long time but haven't found a suitable (inexpensive) alternative yet. > > Sebastien > >> On Aug 10, 2017, at 10:21, user9253 <fransew@gmail.com> wrote: >> >> >> Sebastien, I had posted previously that there was something wrong with the charging system. That was based on your post saying that the alternator voltage was low, between 13 to 13.5 >> Now you are saying that the charging voltage is normal. So now I think that either the battery is bad or there is bad battery connection. >> >> -------- >> Joe Gores >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=471713#471713 >> >> >> >> >> >> >> >> >> > > > >


    Message 13


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    Time: 12:56:27 PM PST US
    Subject: Re: Fuse Blocks
    From: "user9253" <fransew@gmail.com>
    Here you go Gilles, a picture of the rear of the fuse block. Do not let the reflection in the aluminum confuse. In the reflection, the wires can be seen making a 180 degree turn before being soldered to the PCB. No worry about stiff soldered wires breaking because they are no longer stiff where exiting through the holes in the board. The top 3 rows are one continuous copper PCB layer on both sides of the board. The solder mask hides the copper. The top 3 rows really are continuous. The main power bus is nothing more than the copper layers on the circuit board. I had considered soldering a 6 inch long #14 or #12 AWG wire along the bus to increase its capacity. I did not because my RV-12 only uses about 10 amps total. The #12 wire from the aircraft battery contactor is spliced to 4 each of 18 AWG wires that are soldered to the top row of the bus. The alternator (dynamo) is similarly connected with 4 of 18 AWG wires to the bottom of a 30 amp fuse (back fed to the bus). This fuse block has about an hour of Hobbs time. So far no problems. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=471721#471721 Attachments: http://forums.matronics.com//files/dsc00677a_106.jpg


    Message 14


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    Time: 01:22:03 PM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Another Alternator Question
    At 10:08 AM 8/10/2017, you wrote: > >Bob et Al > >I have been reading the AEC trying to get smart(er) on alternators >and failure modes etc. The "Z" diagrams are quite informative. > >As the -10 I am building will have EFI/EI I want to make sure that I >understand what happens when electrical things fail. The one failure >I am unsure about is the battery contactor. > >For example, if I am trundling along at altitude with all my >electro-goodies powered up and the battery contactor fails, what >happens (assuming I am wired in accordance with the Z13/8 diagram). Not much . . . > I know that the OV protection will deal with voltage spikes. Is > there anything else to be concerned about such as a current spike > (if it exists)? I would guess that the most shop-worn topic in discussion of vehicular dc power systems is 'spikes'. Most of what circulates as learned assertions and worrisome concerns is not based on good physics or practical design going back 100 years or so. To lay foundation for the answer to your question, I'll refer you first to this 2-bit tour of a legacy qualification protocol for electro-whizzies to to into airplanes. http://tinyurl.com/ydctrct5 These tests equal or exceed the stresses known to be deleterious to performance or hazardous to longevity for electrical/electronic appliances. Note that for a 14 volt airplane, the greatest expected surges is 20 volts for 1 second and 40 volts for 100 milliseconds. These are what might be termed high-energy perturbations. They ALWAYS originate with a malfunction in the ship's power generation (alternator or generator). The only thing DO-160 calls a 'spike' is the 300v spike test. While a alarmingly 'high' number, the voltage is delivered from a high impedance source (50 ohms) with a duration on the order of 100 microseconds. Relatively low energy and easily managed with rudimentary design techniques for the appliance being tested. The significance of these tests is not so much what they IS FOUND to be significant risk, but the absence of a test that the automotive industry calls a "load dump". The in automotive vernacular, the worst case "load dump" occurs when an alternator is near or at rated output where (1) system requirements are small and (2) the BATTERY is severely discharged and is demanding a very high charge rate. Under this condition, disconnecting the battery is like cutting the rope during a tug-of-war game. The sudden release of 'tension' causes a high energy overshoot of the alternator's output that persists until the alternator's regulator can bring it under control. The full effects of this overshoot are impressed on what ever appliances are in operation at the time. Here's the test setup for evaluating the alternator/ regulator response to an automotive 'load dump'. http://tinyurl.com/yapuhf2s DO-160 doesn't suggest testing for this kind of event because (1) it is poor practice to take off with a badly discharged battery and (2) even if you do . . . likelihood of loss of contactor coincident with launching into the blue with a depleted battery is very low. the scenario you describe, loss of contactor during cruising flight is a low probability event in the first place. If you do, your battery will most likely be in a high state of charge. Under these conditions contactor failure will probably not even be noticed until you shut down the alternator before shutting down the engine whereupon the panel goes dark immediately. This would be cause for investigation of the failure at the end of your current flight. If, as some POHs suggest, the alternator/battery switch is turned off before stopping the engine, then you won't know the contactor is gone until next preflight. Based on the way airplanes are operated, the automotive style load dump represents no significant risk. I've never heard it even mentioned in 50 years of conversation in airplane-speak. In the big airplanes, taking a battery off line in flight is discussed in the POH in responses to certian system failures were the airplane is expected to continue flight sans battery with no problems. Bob . . .


    Message 15


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    Time: 04:31:14 PM PST US
    Subject: Re: Another Alternator Question
    From: "user9253" <fransew@gmail.com>
    Les, last year my PC680 battery failed suddenly while flying. It turned out to be an internal open circuit. The affect is identical to a master contactor failure. The Dynon D-180 gave a high voltage alarm. I can not remember what it was, but probably not more than one volt above normal. The voltage was definitely not high enough to cause any damage to electrical loads. Analyzing the data from the D-180 showed that the voltage was unstable without the battery connected and varied above and below the set point by a volt or so. Again, it was enough to set off alarms, but not enough to damage my electronics, which are rated for 10 to 30 volts. Based on my experience, a failed battery contactor (or any open battery circuit) will not cause any damage to any electrical load, including avionics. And a failed battery contactor does not create an in-flight emergency. All of my electrical equipment kept working normally powered by the alternator without a battery. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=471725#471725


    Message 16


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    Time: 07:03:30 PM PST US
    Subject: Re: Another Alternator Question
    From: "kearney" <kearney@shaw.ca>
    Bob / Joe Thank you for the info it is most helpful. Given that an alternator will continue to function even if the battery goes offline, some of my redundancy concerns have been addressed. Based on my application (EFI/EI) the Z-12 dual alternator / single battery architecture looks most appropriate. I have been reviewing each of the various "Z" diagrams trying to understand the logic behind each and how it would operate / meet my needs. I like the Z12 with dual alternators would provide (*I think*) the best redundancy in the event of a failure of one of the electrical system components. The only changes to the Z12 I might consider making would be 1. To move the back up alternator field connecton to the endurance bus. My rational for this is that a failure of of the DPDT MASTER Switch would take the main alternator offline perhaps before the backup could energize. If that happened, there would be no way to energize the backup alternator field. If normal ops had the E-Bus Alternate switch always closed, the backup alternator would be energized automatically from the battery via the EBUS. 2. I would eliminate the always hot bus (I wouldn't use it) and put all my engine EFI/EI circuits and essential avionics on the endurance bus. All other avionics etc would be on the main bus. Some of the EFI/EI components are not switched. 3. Eliminate the alternator loadmeters & hall sensor. I believe the EFIS screens will provide current info. 4. Eliminate the MAIN VOLTS WARN light. In this case the EFIS should provide bus voltage info. I would also forgo use of the Vertical Power VP-X (as originally planned) as it wouldn't be adding a lot of value above and beyond using circuit breakers. Does the above seem reasonable? I'd appreciate any comments / suggestions about this or anything I may have missed. Cheers Les Read this topic online here: http://forums.matronics.com/viewtopic.php?p=471730#471730


    Message 17


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    Time: 08:19:30 PM PST US
    Subject: Re: Another Alternator Question
    From: "user9253" <fransew@gmail.com>
    Your alternator will most likely continue to operate without a battery. But that should be confirmed in your aircraft. 1. About the backup alternator: Read Bob's recent post about operating both alternators simultaneously: http://forums.matronics.com/viewtopic.php?t=16767029 Keep in mind that the E-Bus diode will drop the voltage somewhere between 0.5 and 1.2 volts. The voltage regulator should be monitoring alternator output voltage, not the voltage after it has been reduced by a diode. 2. Some electronic ignition manufactures recommend connecting their devices directly to the battery. 3. An EFIS will display current but a sensor (shunt or hall effect) is still required. 4. Yes, an EFIS will display voltage and sound an alarm if out of spec. 5. I agree with your decision about VP-X. Also consider fuses. They cost less, weigh less, never fail to open with high current, can be replaced easily without putting the aircraft out of service. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=471734#471734




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