---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 11/22/07: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 0. 12:14 AM - What Are You Thankful For...? (Matt Dralle) 1. 07:01 AM - Re: AeroElectric-List Digest: 21 Msgs - 11/21/07 () 2. 07:52 AM - Re: Question about Relays/Switches (Ernest Christley) 3. 08:04 AM - Re: Running avionics on power supply (Ernest Christley) 4. 03:40 PM - Re: Re: Matt's Profiteering (not) (RV Builder (Michael Sausen)) 5. 06:38 PM - Re: Question about Relays/Switches (Robert L. Nuckolls, III) ________________________________ Message 0 _____________________________________ Time: 12:14:02 AM PST US From: Matt Dralle Subject: AeroElectric-List: What Are You Thankful For...? Dear Listers, Here in the United States, Thursday is our National day of Thanksgiving. Many of us will be traveling to be with our families and friends to share in generous feasts of plenty and giving thanks for many blessings that have been bestowed upon us. Many Listers have expressed over the last couple of weeks how thankful they are for the Email Lists and Forums here on the Matronics servers and for all of the assistance and comradery they have experienced being a part of the Lists. One of my favorite kind of comments is when write to me and says something like, "Its the first thing I do in the morning while I'm having my morning coffee!". That's a wonderful tribute to the purpose and function of these Lists. Its always great to hear I'm not the only one that jumps out of bed each morning to check my List email!! Won't you take a minute today and show your appreciation for these Lists and for their continued operation and upgrade? The List Contribution Site is: http://www.matronics.com/contribution Thank you in advance for your kind consideration, Matt Dralle Matronics Email List Administrator ________________________________ Message 1 _____________________________________ Time: 07:01:15 AM PST US From: Subject: AeroElectric-List: Re: AeroElectric-List Digest: 21 Msgs - 11/21/07 Please remove from list>>>dnl ---- AeroElectric-List Digest Server wrote: > * > > ================================================= > Online Versions of Today's List Digest Archive > ================================================= > > Today's complete AeroElectric-List Digest can also be found in either of the > two Web Links listed below. The .html file includes the Digest formatted > in HTML for viewing with a web browser and features Hyperlinked Indexes > and Message Navigation. The .txt file includes the plain ASCII version > of the AeroElectric-List Digest and can be viewed with a generic text editor > such as Notepad or with a web browser. > > HTML Version: > > http://www.matronics.com/digest/digestview.php?Style=82701&View=html&Chapter 07-11-21&Archive=AeroElectric > > Text Version: > > http://www.matronics.com/digest/digestview.php?Style=82701&View=txt&Chapter 07-11-21&Archive=AeroElectric > > > =============================================== > EMail Version of Today's List Digest Archive > =============================================== > > > ---------------------------------------------------------- > AeroElectric-List Digest Archive > --- > Total Messages Posted Wed 11/21/07: 21 > ---------------------------------------------------------- > > > Today's Message Index: > ---------------------- > > 1. 05:08 AM - Running avionics on power supply (Ralph E. Capen) > 2. 05:54 AM - Re: Running avionics on power supply (JOHN TIPTON) > 3. 06:56 AM - Tefzel cables and d-sub connectors (Terry Phillips) > 4. 07:05 AM - Battery Replacement STC () > 5. 08:10 AM - Re: Tefzel cables and d-sub connectors (Ben Westfall) > 6. 09:46 AM - Re: Location of battery bus () > 7. 10:05 AM - Re: Running avionics on power supply (mwcreek@frontiernet.net) > 8. 10:49 AM - Re: Running avionics on power supply (Ralph E. Capen) > 9. 12:11 PM - Re: Running avionics on power supply (mwcreek@frontiernet.net) > 10. 03:15 PM - Re: Re: Pullable 60 Amp Breaker (Robert L. Nuckolls, III) > 11. 03:52 PM - Re: Re: Pullable 60 Amp Breaker (Robert L. Nuckolls, III) > 12. 04:02 PM - Re: Question about Relays/Switches (Robert L. Nuckolls, III) > 13. 04:05 PM - Re: Radio interlock (Robert L. Nuckolls, III) > 14. 04:06 PM - Re: Battery Replacement STC (Robert L. Nuckolls, III) > 15. 04:45 PM - Re: Location of battery bus () > 16. 04:46 PM - Re: Tefzel cables and d-sub connectors (The Kuffels) > 17. 05:46 PM - Re: Re: Pullable 60 Amp Breaker (Marvin Dorris Jr) > 18. 07:44 PM - Re: Tefzel cables and d-sub connectors (Robert L. Nuckolls, III) > 19. 08:15 PM - Re: Location of battery bus (Bill Schlatterer) > 20. 08:47 PM - Re: Re: Pullable 60 Amp Breaker (Robert L. Nuckolls, III) > 21. 08:58 PM - Re: Running avionics on power supply (Robert L. Nuckolls, III) > > > > ________________________________ Message 1 _____________________________________ > > > Time: 05:08:33 AM PST US > From: "Ralph E. Capen" > Subject: AeroElectric-List: Running avionics on power supply > > > No replies to my initial post, so trying again.... > > Should there be any issues in running my electrical system with a power supply > instead of the alternater/engine running? I have a battery in the circuit (PC680). > > Do I need to connect the power supply directly to the battery or can I hook it > to my shunt to simulate the power coming from the alternator? > > Just want to make sure that I don't fry anything..... > > Ralph Capen > > > ________________________________ Message 2 _____________________________________ > > > Time: 05:54:33 AM PST US > From: "JOHN TIPTON" > Subject: Re: AeroElectric-List: Running avionics on power supply > > > Likewise: I have a CB power supply (13.8v 3amp) which I thought of using to > power up the system - to the vacant battery terminal or where? > > John > > ----- Original Message ----- > From: "Ralph E. Capen" > > Sent: Wednesday, November 21, 2007 12:56 PM > Subject: AeroElectric-List: Running avionics on power supply > > > > > > > > No replies to my initial post, so trying again.... > > > > Should there be any issues in running my electrical system with a power > > supply instead of the alternater/engine running? I have a battery in the > > circuit (PC680). > > Do I need to connect the power supply directly to the battery or can I > > hook it to my shunt to simulate the power coming from the alternator? > > > > Just want to make sure that I don't fry anything..... > > > > Ralph Capen > > > > > > > > > ________________________________ Message 3 _____________________________________ > > > Time: 06:56:41 AM PST US > Subject: AeroElectric-List: Tefzel cables and d-sub connectors > From: "Terry Phillips" > > > I am have reached the point in my building where I have to address some electrical > design issues. I need to install the servo for the R.A. Allen electric elevator > trim tab. The servo has 5 leads, and is supplied with a length of 5-conductor > Belden 8445 cable to connect to the controls in the cockpit. A check on > the Internet shows that this cable is PVC insulated with 5 22AWG wires. I have > a several questions. > > 1. I was planning to use Tefzel insulated cable as much as possible. Is it worthwhile > to replace R.A. Allen's PVC insulated cable with Tefzel insulated cable? > > 2. For this application cable would be better than 5 individual wires, because > the wires must pass outside the skin from the elevator to the fuselage. After > looking around on the Internet, I was unable to find a 5-conductor cable with > Tefzel wire insulation and a Tefzel jacket. I did find a company, TPC Wire, > > http://www.tpcwire.com/tpc/pdf/03_TrOxCable_6.pdf, > > that sells 100 ft lengths of shielded cable with Tefzel wire insulation and a polyurethane > exterior cover that should work (part no. 61506). They don't have > 5 conductor cable, but the 6 conductor cable would not be much heavier. Does such > a cable look like a reasonable substitute? Are there other sources for Tefzel > insulated cable that I should consider? > > 3. The servo instructions suggest soldering the cable conductors to the servo leads > and wrapping the joints with electrical tape. I was originally planning to > use butt splice crimp connectors instead of soldering. I'm now considering using > a 9 conductor d-sub plug. Are the d-sub plugs a good choice for a remote > location, like the elevator? > > 4. If one uses a d-sub, should the plug itself be secured to the elevator (how?) > or would cable ties or an adel clamps on the cable provide adequate support. > > 5. Also, since TPC Wire has a $100 minumum order, it behooves me to buy cable for > other uses in the airplane in this one order. E.g., power for the nav lights, > headlights, etc. One use that I'm considering is to buy some 24 conductor cable > to pass through the firewall to carry engine instrument signals. Which brings > me back to the d-sub connectors. Would d-subs be reasonable replacement for > the terminal strips that I have seen used to connect engine instruments to > wires passing through the firewall? Can d-subs handle engine compartment temperatures? > Will thermocouple leads crimped into d-sub pins work OK? Are d-subs robust > enough to endure the correction of wiring goofs? > > -------- > Terry Phillips > Corvallis, MT > ttp44<at>rkymtn.net > Zenith 601XL/Jab 3300 slow build kit - Rudder done--finally; working on the stab > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=147691#147691 > > > ________________________________ Message 4 _____________________________________ > > > Time: 07:05:02 AM PST US > From: > Subject: AeroElectric-List: Battery Replacement STC > > > 11/21/2007 > > Hello Bob Nuckolls and other list experts, My friend wants to replace the > two conventional 12 volt lead acid Gill batteries in his 24 volt system > Beech Sierra with two 12 volt Concorde recombinant gas batteries. > > I can find tables that shows the correct batteries, but also show that an > STC (held by Wilco) is involved: > > http://www.concordebattery.com/aag3.php?id=2775 > > http://www.aircraftspruce.com/catalog/pdf/finalfaapma.pdf (see page 8) > > What is the proper procedure / FAA required paperwork / permission from STC > holder, to make this battery switch? > > Thanks. > > 'OC' Says: "The best investment we can make is the effort to gather and > understand knowledge." > > > ________________________________ Message 5 _____________________________________ > > > Time: 08:10:17 AM PST US > From: "Ben Westfall" > Subject: RE: AeroElectric-List: Tefzel cables and d-sub connectors > > > Terry, > > Bob has a decent webpage that covers your question #3 below. > > http://www.aeroelectric.com/articles/macservo/macservo.html > > There is another good article on "Soldering D-Sub Connectors" that can be > found here: > > http://www.aeroelectric.com/articles/dsubs/d_solder.html > > > -Ben Westfall > > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Terry > Phillips > Sent: Wednesday, November 21, 2007 6:55 AM > Subject: AeroElectric-List: Tefzel cables and d-sub connectors > > > I am have reached the point in my building where I have to address some > electrical design issues. I need to install the servo for the R.A. Allen > electric elevator trim tab. The servo has 5 leads, and is supplied with a > length of 5-conductor Belden 8445 cable to connect to the controls in the > cockpit. A check on the Internet shows that this cable is PVC insulated with > 5 22AWG wires. I have a several questions. > > 1. I was planning to use Tefzel insulated cable as much as possible. Is it > worthwhile to replace R.A. Allen's PVC insulated cable with Tefzel > insulated cable? > > 2. For this application cable would be better than 5 individual wires, > because the wires must pass outside the skin from the elevator to the > fuselage. After looking around on the Internet, I was unable to find a > 5-conductor cable with Tefzel wire insulation and a Tefzel jacket. I did > find a company, TPC Wire, > > http://www.tpcwire.com/tpc/pdf/03_TrOxCable_6.pdf, > > that sells 100 ft lengths of shielded cable with Tefzel wire insulation and > a polyurethane exterior cover that should work (part no. 61506). They don't > have 5 conductor cable, but the 6 conductor cable would not be much heavier. > Does such a cable look like a reasonable substitute? Are there other sources > for Tefzel insulated cable that I should consider? > > 3. The servo instructions suggest soldering the cable conductors to the > servo leads and wrapping the joints with electrical tape. I was originally > planning to use butt splice crimp connectors instead of soldering. I'm now > considering using a 9 conductor d-sub plug. Are the d-sub plugs a good > choice for a remote location, like the elevator? > > 4. If one uses a d-sub, should the plug itself be secured to the elevator > (how?) or would cable ties or an adel clamps on the cable provide adequate > support. > > 5. Also, since TPC Wire has a $100 minumum order, it behooves me to buy > cable for other uses in the airplane in this one order. E.g., power for the > nav lights, headlights, etc. One use that I'm considering is to buy some 24 > conductor cable to pass through the firewall to carry engine instrument > signals. Which brings me back to the d-sub connectors. Would d-subs be > reasonable replacement for the terminal strips that I have seen used to > connect engine instruments to wires passing through the firewall? Can d-subs > handle engine compartment temperatures? Will thermocouple leads crimped into > d-sub pins work OK? Are d-subs robust enough to endure the correction of > wiring goofs? > > -------- > Terry Phillips > Corvallis, MT > ttp44<at>rkymtn.net > Zenith 601XL/Jab 3300 slow build kit - Rudder done--finally; working on the > stab > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=147691#147691 > > > ________________________________ Message 6 _____________________________________ > > > Time: 09:46:44 AM PST US > Subject: RE: AeroElectric-List: Location of battery bus > From: > > I am at the same decision point. There seems to be a funny rumor out > there that the battery buss needs to be sitting on top of the battery. > Voltage drop for 12-14 volts may be an issue over 12' but not over 12". > I will mount them inside where it is clean and dry but still close to > the firewall. > > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bill > Schlatterer > Sent: Wednesday, November 21, 2007 12:21 AM > Subject: RE: AeroElectric-List: Location of battery bus > > > Bevan, this is what I did on my 7a for block locations. Small > Tab forest on FW side to large forest on cabin side. Fuse blocks on the > inside are on a swing down tray. Ran the battery lead to the always hot > bus to a fuse slot which really protects the wrong end of the wire but > it seemed better than nothing (maybe a fusible link on the battery end > would be better). Wire is about 14" from Battery to bus as I remember > it but not likely to have a problem. > > Bill S > 7a > > ________________________________ > > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of B > Tomm > Sent: Tuesday, November 20, 2007 3:28 AM > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: Location of battery bus > > > Good morning Bob, > > Considering Z-13/20 architecture in an RV7A. The Vans > recommended position for the battery is on the firewall in the engine > compartment which I agree with. That being said, the contactors would > be located nearby. Would it follow that the battery bus should also be > located on the engine side of the firewall and if so, would it be > appropriate to use a fuse block style as we've come to appreciate? In > other words, would the fuse block style and associated faston terminals > stand up in the FF environment? I would prefer to see the fuses inside > the cockpit just aft of the firewall (cleaner environment), but to get > to here there would be a little more than 6 inches of unprotected wire. > > Thanks again. > > Bevan > > > href="http://www.matronics.com/contribution">http://www.matronics.com/c > h > ref="http://www.matronics.com/Navigator?AeroElectric-List">http://www.m > a > tronics.com/Navigator?AeroElectric-List > href="http://forums.matronics.com">http://forums.matronics.com > > > ________________________________ Message 7 _____________________________________ > > > Time: 10:05:53 AM PST US > From: "mwcreek@frontiernet.net" > Subject: Re: AeroElectric-List: Running avionics on power supply > > > FWIW, > > I've been powering my pannel from a PC680 with a battery charger > connected to it and have not had any problems. The charger output > voltage was fluctuating (or I had bad connections) when I powered > directly from it so using the battery as a sink made it work just > fine. The follwing equipment is being powered this way: > > GRT Sport > SL30 > GTX327 > GRT EIS > TT AP > PSE 3000 > > Hope this helps, > Mike > > Quoting JOHN TIPTON : > > > > > > > Likewise: I have a CB power supply (13.8v 3amp) which I thought of > > using to power up the system - to the vacant battery terminal or where? > > > > John > > > > ----- Original Message ----- From: "Ralph E. Capen" > > To: "Aeroelectric-list" ; "Avionics > > List" > > Sent: Wednesday, November 21, 2007 12:56 PM > > Subject: AeroElectric-List: Running avionics on power supply > > > > > >> > >> > >> No replies to my initial post, so trying again.... > >> > >> Should there be any issues in running my electrical system with a > >> power supply instead of the alternater/engine running? I have a > >> battery in the circuit (PC680). > >> Do I need to connect the power supply directly to the battery or > >> can I hook it to my shunt to simulate the power coming from the > >> alternator? > >> > >> Just want to make sure that I don't fry anything..... > >> > >> Ralph Capen > >> > >> > >> > >> > >> > >> > >> > >> > >> > > > > > > > ________________________________ Message 8 _____________________________________ > > > Time: 10:49:34 AM PST US > From: "Ralph E. Capen" > Subject: Re: AeroElectric-List: Running avionics on power supply > > > Your charger is connected directly to the battery? > > -----Original Message----- > >From: "mwcreek@frontiernet.net" > >Sent: Nov 21, 2007 1:01 PM > >To: aeroelectric-list@matronics.com > >Subject: Re: AeroElectric-List: Running avionics on power supply > > > > > >FWIW, > > > >I've been powering my pannel from a PC680 with a battery charger > >connected to it and have not had any problems. The charger output > >voltage was fluctuating (or I had bad connections) when I powered > >directly from it so using the battery as a sink made it work just > >fine. The follwing equipment is being powered this way: > > > >GRT Sport > >SL30 > >GTX327 > >GRT EIS > >TT AP > >PSE 3000 > > > >Hope this helps, > >Mike > > > >Quoting JOHN TIPTON : > > > >> > >> > >> Likewise: I have a CB power supply (13.8v 3amp) which I thought of > >> using to power up the system - to the vacant battery terminal or where? > >> > >> John > >> > >> ----- Original Message ----- From: "Ralph E. Capen" > >> To: "Aeroelectric-list" ; "Avionics > >> List" > >> Sent: Wednesday, November 21, 2007 12:56 PM > >> Subject: AeroElectric-List: Running avionics on power supply > >> > >> > >>> > >>> > >>> No replies to my initial post, so trying again.... > >>> > >>> Should there be any issues in running my electrical system with a > >>> power supply instead of the alternater/engine running? I have a > >>> battery in the circuit (PC680). > >>> Do I need to connect the power supply directly to the battery or > >>> can I hook it to my shunt to simulate the power coming from the > >>> alternator? > >>> > >>> Just want to make sure that I don't fry anything..... > >>> > >>> Ralph Capen > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >>> > >> > >> > > > > > > > ________________________________ Message 9 _____________________________________ > > > Time: 12:11:25 PM PST US > From: "mwcreek@frontiernet.net" > Subject: Re: AeroElectric-List: Running avionics on power supply > > > yes, the battery charger is connected directly to the battery. > > Quoting "Ralph E. Capen" : > > > > > > > Your charger is connected directly to the battery? > > > > -----Original Message----- > >> From: "mwcreek@frontiernet.net" > >> Sent: Nov 21, 2007 1:01 PM > >> To: aeroelectric-list@matronics.com > >> Subject: Re: AeroElectric-List: Running avionics on power supply > >> > >> > >> > >> FWIW, > >> > >> I've been powering my pannel from a PC680 with a battery charger > >> connected to it and have not had any problems. The charger output > >> voltage was fluctuating (or I had bad connections) when I powered > >> directly from it so using the battery as a sink made it work just > >> fine. The follwing equipment is being powered this way: > >> > >> GRT Sport > >> SL30 > >> GTX327 > >> GRT EIS > >> TT AP > >> PSE 3000 > >> > >> Hope this helps, > >> Mike > >> > >> Quoting JOHN TIPTON : > >> > >>> > >>> > >>> Likewise: I have a CB power supply (13.8v 3amp) which I thought of > >>> using to power up the system - to the vacant battery terminal or where? > >>> > >>> John > >>> > >>> ----- Original Message ----- From: "Ralph E. Capen" > >>> To: "Aeroelectric-list" ; "Avionics > >>> List" > >>> Sent: Wednesday, November 21, 2007 12:56 PM > >>> Subject: AeroElectric-List: Running avionics on power supply > >>> > >>> > >>>> > >>>> > >>>> No replies to my initial post, so trying again.... > >>>> > >>>> Should there be any issues in running my electrical system with a > >>>> power supply instead of the alternater/engine running? I have a > >>>> battery in the circuit (PC680). > >>>> Do I need to connect the power supply directly to the battery or > >>>> can I hook it to my shunt to simulate the power coming from the > >>>> alternator? > >>>> > >>>> Just want to make sure that I don't fry anything..... > >>>> > >>>> Ralph Capen > >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > >>> > >>> > >> > >> > >> > >> > >> > >> > >> > >> > > > > > > > ________________________________ Message 10 ____________________________________ > > > Time: 03:15:50 PM PST US > From: "Robert L. Nuckolls, III" > Subject: Re: AeroElectric-List: RE: Pullable 60 Amp Breaker > > > > From: > Subject: AeroElectric-List: RE: Pullable 60 Amp Breaker > > > > > >First, know that designers of upper-end production aircraft > > >have made a effort to get high-current, noise-carrying > > >conductors off the panel. > > > >Never heard noise in my plane with B-lead CB in panel. > >I would just say prove it. Modern internally regulated alternators > >are not noisy so it's a moot point. Old Gen from days gone by, yes > >noisy. > > George, this has nothing to do with the style of > regulator. 3-phase rectified AC has a 5% built-in ripple > component that is a physical artifact of the product. > I've encountered magnetically coupled noises in both > automobiles and aircraft. So your statement about "modern > internally regulated alternators not being noisy" is > demonstrably in error and your admonition to "prove it" > is a manifestation of your proven history of inability > or unwillingness to carry on discussions based on > physics and simple-ideas. > > I've troubleshot and fixed a number of magnetically > coupled alternator whine problems on aircraft and once > in my own automobile. It's doubtful that any demonstration > would be sufficient "proof" to make this phenomenon > real and significant in your limited understanding. > Alternators are much more noisy than generators. > > > > >Third, it has been suggested that a breaker might serve > > >as the last-ditch means by which a pilot can bring a runaway > > >alternator to heel . . . or at least disconnect it from the > > >system. This logic is flawed for several reasons: (1) breakers > > >are designed to disconnect hard downstream faults in a system > > >where the voltage are on the order of 32 volts or less. (2) > > >A runaway alternator is capable of raising the b-lead terminal > > >to hundreds of volts in milliseconds where it is NOT reasonable > > >to expect the breaker to also serve as a SWITCH for reliable > > >disconnect of the offending alternator. Any attempt to use > > >a breaker (particularly a miniature one with plastic housing!) > > >or this purpose is to flirt with probability of cockpit fire > > >and much smoke. > > > >With all due respect I think your logic is flawed. It may fit for external > >regulated alternators but not for internally regulated ones. > > It matters not what style of alternator is being > considered, any alternator running self-excited by > a field voltage which is a product of it's own output > is capable of well over 100 volts of output. See: > > http://aeroelectric.com/articles/When_is_110V_not_Over_Voltage.pdf > > > > >A CB is RATED to disconnect at 32 volts many many times, however > >it can handle much more. No I don't have an absolute number but > >when most 12 volt alternators with a so called over voltage rarely > >exceeds 17 v much less 32 v, your point is moot, 32v good enough. > > Yes, the runaway alternators that were NOT putting out > hundreds of volts were being loaded by a battery that > was dutifully sacrificing itself by accepting what the > alternator could deliver due to its inherent current > limiting. > > But the very act of opening the b-lead on a runaway > alternator disconnects the battery and all other parts > of the ship's systems. As soon as the contacts of the > 'switch' open, the alternator becomes unrestrained and > b-lead voltage will rise rapidly to values much greater > than the 32-volt rating of the breaker. Once you strike > the arc between the opening contacts, one has 100+ > volts at 40-60 amps (4,000+ watts) of potential power > being dumped into the fire. This would probably be > contained by an all-metal enclosure like: > > http://www.aeroelectric.com/Pictures/Contactors/s701-1.jpg > > but enclosures like this . . . > > http://www.aeroelectric.com/Pictures/Contactors/6041_Contactor.jpg > > . . . have proven incapable of containing such fires > > http://www.aeroelectric.com/Pictures/Failures/6041_Contactor_Failure.jpg > > > > > >When you say 100's of VOLTS and Cockpit FIRE, it's fear mongering > >not based on facts. Science and engineering are based on facts not > >emotional reasons. CB catch on fire? Really? OK, prove it. > > It is an absolute certainty that an enclosure like this > > http://www.aeroelectric.com/Pictures/Breakers/circuitbreakers.jpg > > will not contain such fires either. > > > > >Small 40 / 60 amp alternators are not pumping 100's of volts or amps. > >Internally regulated alternators typically go to 16 or 17 volts, if > >regulation fails, easily controlled by a CB. Yes there may have > >been one "screw lose" case where voltage was truly out of control, > >but it's rare, and the voltage was undetermined. I doubt it got to > >over 32 volts. > > As soon as the runaway alternator is disconnected from > the system by pulling a breaker, the battery is relieved > of sacrificial duties and the voltage at the alternator's > b-lead will rise rapidly and to magnitudes previously cited. . . > the Mother of All Load Dumps. > > > > >Also an ANL fuse will not blow with 100's of volts, it's a current > >device. If you want to wire your airplane like a Toyota with fuses, fine, > >but there is no need to make stuff up against CB's in the panel. > > Fuses are not expected to protect against over-voltage events > but over-current events. Know that a runaway alternator has > NEVER put out more current that what's established by the > physics of it's magnetics. I.e, not enough to open the > b-lead protection irrespective of it's design (assuming > it is sized for sufficient headroom to avoid nuisance > tripping). Nonetheless, bus voltages are carried upward > to many times greater than normal bus voltage unless > some well considered means for stopping it has been included > in the design. > > > > >Finally, know that a 60A breaker on a 60A alternator is > > >DESIGNED to nuisance trip. The b-lead protection on an alternator > > >should stay closed at current levels perhaps 20% higher than > > >the nameplate rating of the alternator. The GA spam-can community > > >really blew it when 60A b-lead breakers were installed in 100,000+ > > >aircraft with 60A alternators. > > > >Easily solved by sizing the CB properly. I guess they don't have > >smart people working for the GA spam-can community. Frankly CB's > >can take slight overloads for a period of time with out a trip. Again > >moot point Bob, if the alternator can only put out 45 amps. > > That's what I said. The 60A breaker is too small for > being used with a 60A alternator. Yes, MOST nuisance > tripping is avoided by the noteworthy time delays > inherent in the design of CBs . . . but the majority > of nuisance trips of breakers in light aircraft are > the 60A b-lead breaker tied to a 60A alternator. > > Your off-hand comment about the intelligence of folks > working in GA is uncalled for and yet another manifestation > of your long and oft demonstrated history of belligerent, > ill-informed, nay ignorant participation on this List. > There are MANY folks within GA that would very much > like to rectify the condition cited . . . but it's never > bubbled to the top-ten-problems list with an airframe OEM and > the FAA makes it insanely $difficult$ to make even the > simplest changes. Hence, this marginal design has > endured for decades more out of resignation to the > authority of a higher power than of ignorance or apathy. > > > > >In my humble opinion, ignoring a lot of experience and > > >thoughtful reasoning suggesting that panel a mounted, b-lead > > >breaker is not the best-we-know-how-to-do. > > >Bob . . . > > > >What? > > > >Fuses are fine. Buth with (stock) internal regulation the CB is a good > >reason to use a B-lead CB. Other engineers have worked on this > >Bob. The pull-able CB for the B-lead is specified. It's irresponsible of > >you to be so stubborn and opinionated, making ONE blanked edict > >that one size fits all. Fuses are not a BE ALL solution for every > >application. Follow the manufactures recommendation! > > This isn't a fuses/breakers discussion, it's > an examination of the physics which govern assembly > of some exceedingly simple ideas into recipes for > success with an acknowledgment of hazards which > should be considered as part of a thoughtful design. > > > > >In my humble opinion, I disagree with Bob with my thoughtful reasoning > >and facts. I don't care what you use but know why you are using it. I > >don't believe you will have noise or won't be able to disconnect the > >b-lead manually if you want to. When people talk 100's of volts & fire > >they are exaggerating in non-scientific emotional arguments, not > >engineering. Have Bob prove these are real problems. I could come > >up with lots of NIT PICK reasons a fuse really is a poor choice. > > George, you have been politely requested to keep > your comments on this topic to yourself . . . they've > been read many times for years on this List and debunked > as recorded and published at: > > http://www.aeroelectric.com/articles/gmcjetpilot.html > > http://aeroelectric.com/articles/The_Truth_about_Crowbar_OV_Protection.pdf > > You have designed nothing, fixed nothing, contributed > nothing to the understanding of physics, serviced no > customers, taught no classes, or offered a 100% satisfaction > assured warranty for your products. Yet you persist > in lurking at the edges of a sandbox not of your > construction to throw rocks and mud while hiding behind > a pseudonym decorated with much alphabet soup of > self proclaimed titles/accolades. You claim superior > engineering insight while never having demonstrated > it with useful work-product. > > I've demonstrated/experienced/explained every assertion > I've ever made based on my hands-on experiences with these > systems since I did my first OV relay design for Cessna > Aircraft in 1975. Your belittling diatribes and circular > arguments contribute nothing to the advancement of > our science, understanding or art and yet you deign to > call me a liar. Your brand of 'science' is not welcome > in this classroom. You sir are the secretive, fraudulent > participant in these discussions and I will ask you > politely for the third or forth time, please go away. > > Bob . . . > > (---------------------------------------) > ( . . . a long habit of not thinking ) > ( a thing wrong, gives it a superficial ) > ( appearance of being right . . . ) > ( ) > ( -Thomas Paine 1776- ) > (---------------------------------------) > > > ________________________________ Message 11 ____________________________________ > > > Time: 03:52:45 PM PST US > From: "Robert L. Nuckolls, III" > Subject: RE: AeroElectric-List: RE: Pullable 60 Amp Breaker > > > At 04:12 PM 11/20/2007 -0600, you wrote: > > >Why would anyone want to reset a tripped 60A breaker in flight ? > > > >If you want to disable the alternator than switching off the alternator > >field would generate a lot less transients that components have to deal with. > > Yes, you'll have to research this topic in the > archives a bit. It's not about whether or not > one should 'reset' a tripped breaker but one > of selecting design goals. I.e, is it (1) > reasonable to assume an alternator with a "broken" > internal regulator can be depended upon to > remain at or below 17 volts and (2) > depend on a panel mounted b-lead breaker > to disconnect said alternator from the bus > after (3) the pilot becomes aware of the OV > condition. > > It has been suggested that this design > goal is a suitable alternative to architectures > and goals embraced by the vast majority > of the TC aviation community. > > Bob . . . > > > ----------------------------------------) > ( . . . a long habit of not thinking ) > ( a thing wrong, gives it a superficial ) > ( appearance of being right . . . ) > ( ) > ( -Thomas Paine 1776- ) > ---------------------------------------- > > > ________________________________ Message 12 ____________________________________ > > > Time: 04:02:07 PM PST US > From: "Robert L. Nuckolls, III" > Subject: RE: AeroElectric-List: Question about Relays/Switches > > > At 03:58 PM 11/20/2007 -0700, you wrote: > > > > >Bob, > > > >Thank you much for the information. Those look like the regular vanilla > >automotive relays that I have used for years in cars. > > > >Are those suitable for our applications? I am just not certain I want to > >entrust tens of thousands of dollars of my airplane and its ESSENTIAL BUS to > >a $9 relay. > > Sure, why not? What can a relay DO that puts the > equipment at risk? In this case, it's used in but > on of two power paths which should share no common > hardware. So if one path is down it is (1) preflight > detectable, (2) does not cause an immediate hazard > to flight for in flight failure. > > > >If that's the case, I could use a SPDT continuous duty relay (like a Marine > >application) found here - > >http://www.ebasicpower.com/pc/ARCR038/ALLRELAYS/Relay%2C+12V%2C+85+Amp%2C+S. > >P.D.T. to power my E-Bus from my Main Battery. > > How big are the loads on your e-bus? > > > >I could even get radical and have the Main Battery power my E-Bus when the > >coil is energized and have it switch to my Aux Battery when coil is not > >energized. Since there is already a SPST Continuous Duty Relay upstream of > >both my main battery and aux battery, powering down the plane shouldn't be a > >problem. > > >Thoughts? > > Methinks thou worriest too much. First, assume > that ANY piece of hardware you incorporate into > your system can and at some time will fail in > flight. The proceed to architecture your system > with the following in mind: > > Nuckolls' first law of airplane systems design sez: "Things > break" > > The second: "Systems shall be designed so that when things > break, no immediate hazard is created." > > The third: "Things needed for comfortable termination of > flight require backup or special consideration to insure > operation and availability" > > The forth: "Upgrading the quality, reliability, longevity, or > capability of a part shall be because you're tired of replacing > it or want some new feature, not because it damned near got > you killed." > > If you've done your homework, then no single > failure of a component will put the flight > at risk for unhappy termination. The thought > process goes toward designing for failure > tolerance as opposed to seeking components > that will never fail. > > Bob . . . > > > ________________________________ Message 13 ____________________________________ > > > Time: 04:05:23 PM PST US > From: "Robert L. Nuckolls, III" > Subject: Re: AeroElectric-List: Radio interlock > > > At 10:23 PM 11/20/2007 -0800, you wrote: > > > > >Bob Archer used to sell (and probably still does) an antenna switch which > >allows for reception on two radios simultaneously and locks out the > >non-transmitting radio (whichever one it is) upon closing the PTT of either. > > Now, THAT'S a different set of circumstances and design > goals. Here there is acknowledgment of risk to a receiver > from a transmitter's output for DIRECTLY paralleled transceivers > on a single antenna. This is a very useful alternative to the > dual antenna installation where it's acceptable to have > the non-transmitting transceiver become unusable while > talking on the other. > > Bob . . . > > > ________________________________ Message 14 ____________________________________ > > > Time: 04:06:24 PM PST US > From: "Robert L. Nuckolls, III" > Subject: Re: AeroElectric-List: Battery Replacement STC > > > At 09:55 AM 11/21/2007 -0500, you wrote: > > > > >11/21/2007 > > > >Hello Bob Nuckolls and other list experts, My friend wants to replace the > >two conventional 12 volt lead acid Gill batteries in his 24 volt system > >Beech Sierra with two 12 volt Concorde recombinant gas batteries. > > > >I can find tables that shows the correct batteries, but also show that an > >STC (held by Wilco) is involved: > > > >http://www.concordebattery.com/aag3.php?id=2775 > > > >http://www.aircraftspruce.com/catalog/pdf/finalfaapma.pdf (see page 8) > > > >What is the proper procedure / FAA required paperwork / permission from > >STC holder, to make this battery switch? > > Call Wilco and I'm sure they'll be able to cite > the process down to the last signature on your > ship's paperwork. Generally speaking, the battery > STC's are probably the simplest of "mods" to accomplish > on a TC aircraft. I crafted a couple of STCs for B&C > some years ago to put Genesis RG batteries (Hawker) > on the smaller Cessnas and Pipers. When you buy > the battery + STC it will come with the proper permission > documents. > > Bob . . . > > ----------------------------------------) > ( . . . a long habit of not thinking ) > ( a thing wrong, gives it a superficial ) > ( appearance of being right . . . ) > ( ) > ( -Thomas Paine 1776- ) > ---------------------------------------- > > > ________________________________ Message 15 ____________________________________ > > > Time: 04:45:41 PM PST US > Subject: RE: AeroElectric-List: Location of battery bus > From: > > Great job Bill. Your work looks good. > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bill > Schlatterer > Sent: Wednesday, November 21, 2007 12:21 AM > To: aeroelectric-list@matronics.com > Subject: RE: AeroElectric-List: Location of battery bus > > > Bevan, this is what I did on my 7a for block locations. Small > Tab forest on FW side to large forest on cabin side. Fuse blocks on the > inside are on a swing down tray. Ran the battery lead to the always hot > bus to a fuse slot which really protects the wrong end of the wire but > it seemed better than nothing (maybe a fusible link on the battery end > would be better). Wire is about 14" from Battery to bus as I remember > it but not likely to have a problem. > > Bill S > 7a > > ________________________________ > > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of B > Tomm > Sent: Tuesday, November 20, 2007 3:28 AM > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: Location of battery bus > > > Good morning Bob, > > Considering Z-13/20 architecture in an RV7A. The Vans > recommended position for the battery is on the firewall in the engine > compartment which I agree with. That being said, the contactors would > be located nearby. Would it follow that the battery bus should also be > located on the engine side of the firewall and if so, would it be > appropriate to use a fuse block style as we've come to appreciate? In > other words, would the fuse block style and associated faston terminals > stand up in the FF environment? I would prefer to see the fuses inside > the cockpit just aft of the firewall (cleaner environment), but to get > to here there would be a little more than 6 inches of unprotected wire. > > Thanks again. > > Bevan > > > href="http://www.matronics.com/contribution">http://www.matronics.com/c > h > ref="http://www.matronics.com/Navigator?AeroElectric-List">http://www.m > a > tronics.com/Navigator?AeroElectric-List > href="http://forums.matronics.com">http://forums.matronics.com > > > ________________________________ Message 16 ____________________________________ > > > Time: 04:46:21 PM PST US > From: The Kuffels > Subject: Re: AeroElectric-List: Tefzel cables and d-sub connectors > > > Terry, > > I have a small amount of Belden 89503 plenum cable. 3-pair > twisted with overall foil shield & drain wire, 24 AWG and Teflon > FEP insulation. Flame and smoke resistant, good to 200 degrees C. > > If this is acceptable for your use let me know the length from > your trim motor to your trim switch. I'll add 5 feet, cut off a > hunk and drop it off in Corvallis. I am driving through Hamilton > Wed Dec 5 and coming back the next day. > > do not archive > > Tom Kuffel > Whitefish, MT > > > ________________________________ Message 17 ____________________________________ > > > Time: 05:46:01 PM PST US > From: Marvin Dorris Jr > Subject: RE: AeroElectric-List: RE: Pullable 60 Amp Breaker > > > With several hundred, uh thousands (they become blurred and seemingly insig > nificant) of flight hours I now attempt a life-long goal of building my ow > n airplane. My self-professed weakness is wiring, electronics and electric > ity in general. Thus, my reason for joining this forum. I read every post > with an open mind and hopefully add to my limited understanding of the tra > veling electron. > > In following this thread of "Pullable 60 Amp Breaker" I am reminded of some > thing I learned a long time ago. The only difference between a jet pilot a > nd a jet engine is the fact that a jet engine stops whining when you shut i > t down. > Happy Thanksgiving & Best Regards to all, > Marvin > > e: Wed, 21 Nov 2007 17:08:17 -0600> To: aeroelectric-list@matronics.com> Fr > om: nuckolls.bob@cox.net> Subject: Re: AeroElectric-List: RE: Pullable 60 A > III" > > > > > Date: Tue, 20 Nov 2007 13:23:04 -0800 > (PST)> From: > Subject: AeroElectric-List: RE: Pull > able 60 Amp Breaker> To: aeroelectric-list@matronics.com> > >> > >First, kn > ow that designers of upper-end production aircraft> > >have made a effort t > o get high-current, noise-carrying> > >conductors off the panel.> >> >Never > heard noise in my plane with B-lead CB in panel.> >I would just say prove > it. Modern internally regulated alternators> >are not noisy so it's a moot > point. Old Gen from days gone by, yes> >noisy.> > George, this has nothing > to do with the style of> regulator. 3-phase rectified AC has a 5% built-in > ripple> component that is a physical artifact of the product.> I've encount > ered magnetically coupled noises in both> automobiles and aircraft. So your > statement about "modern> internally regulated alternators not being noisy" > is> demonstrably in error and your admonition to "prove it"> is a manifest > ation of your proven history of inability> or unwillingness to carry on dis > cussions based on> physics and simple-ideas.> > I've troubleshot and fixed > a number of magnetically> coupled alternator whine problems on aircraft and > once> in my own automobile. It's doubtful that any demonstration> would be > sufficient "proof" to make this phenomenon> real and significant in your l > imited understanding.> Alternators are much more noisy than generators.> > > > > >Third, it has been suggested that a breaker might serve> > >as the las > t-ditch means by which a pilot can bring a runaway> > >alternator to heel . > . . or at least disconnect it from the> > >system. This logic is flawed fo > r several reasons: (1) breakers> > >are designed to disconnect hard downstr > eam faults in a system> > >where the voltage are on the order of 32 volts o > r less. (2)> > >A runaway alternator is capable of raising the b-lead termi > nal> > >to hundreds of volts in milliseconds where it is NOT reasonable> > > >to expect the breaker to also serve as a SWITCH for reliable> > >disconnec > t of the offending alternator. Any attempt to use> > >a breaker (particular > ly a miniature one with plastic housing!)> > >or this purpose is to flirt w > ith probability of cockpit fire> > >and much smoke.> >> >With all due respe > ct I think your logic is flawed. It may fit for external> >regulated altern > ators but not for internally regulated ones.> > It matters not what style o > f alternator is being> considered, any alternator running self-excited by> > a field voltage which is a product of it's own output> is capable of well o > ver 100 volts of output. See:> > http://aeroelectric.com/articles/When_is_1 > 10V_not_Over_Voltage.pdf> > >> >A CB is RATED to disconnect at 32 volts man > y many times, however> >it can handle much more. No I don't have an absolut > e number but> >when most 12 volt alternators with a so called over voltage > rarely> >exceeds 17 v much less 32 v, your point is moot, 32v good enough.> > > Yes, the runaway alternators that were NOT putting out> hundreds of volt > s were being loaded by a battery that> was dutifully sacrificing itself by > accepting what the> alternator could deliver due to its inherent current> l > imiting.> > But the very act of opening the b-lead on a runaway> alternator > disconnects the battery and all other parts> of the ship's systems. As soo > n as the contacts of the> 'switch' open, the alternator becomes unrestraine > d and> b-lead voltage will rise rapidly to values much greater> than the 32 > -volt rating of the breaker. Once you strike> the arc between the opening c > ontacts, one has 100+> volts at 40-60 amps (4,000+ watts) of potential powe > r> being dumped into the fire. This would probably be> contained by an all- > metal enclosure like:> > http://www.aeroelectric.com/Pictures/Contactors/s7 > 01-1.jpg> > but enclosures like this . . .> > http://www.aeroelectric.com/P > ictures/Contactors/6041_Contactor.jpg> > . . . have proven incapable of con > taining such fires> > http://www.aeroelectric.com/Pictures/Failures/6041_Co > ntactor_Failure.jpg> > > > >> >When you say 100's of VOLTS and Cockpit FIRE > , it's fear mongering> >not based on facts. Science and engineering are bas > ed on facts not> >emotional reasons. CB catch on fire? Really? OK, prove it > .> > It is an absolute certainty that an enclosure like this> > http://www. > aeroelectric.com/Pictures/Breakers/circuitbreakers.jpg> > will not contain > such fires either.> > >> >Small 40 / 60 amp alternators are not pumping 100 > 's of volts or amps.> >Internally regulated alternators typically go to 16 > or 17 volts, if> >regulation fails, easily controlled by a CB. Yes there ma > y have> >been one "screw lose" case where voltage was truly out of control, > > >but it's rare, and the voltage was undetermined. I doubt it got to> >ove > r 32 volts.> > As soon as the runaway alternator is disconnected from> the > system by pulling a breaker, the battery is relieved> of sacrificial duties > and the voltage at the alternator's> b-lead will rise rapidly and to magni > tudes previously cited. . .> the Mother of All Load Dumps.> > >> >Also an A > NL fuse will not blow with 100's of volts, it's a current> >device. If you > want to wire your airplane like a Toyota with fuses, fine,> >but there is n > o need to make stuff up against CB's in the panel.> > Fuses are not expecte > d to protect against over-voltage events> but over-current events. Know tha > t a runaway alternator has> NEVER put out more current that what's establis > hed by the> physics of it's magnetics. I.e, not enough to open the> b-lead > protection irrespective of it's design (assuming> it is sized for sufficien > t headroom to avoid nuisance> tripping). Nonetheless, bus voltages are carr > ied upward> to many times greater than normal bus voltage unless> some well > considered means for stopping it has been included> in the design.> > > > > >Finally, know that a 60A breaker on a 60A alternator is> > >DESIGNED to nu > isance trip. The b-lead protection on an alternator> > >should stay closed > at current levels perhaps 20% higher than> > >the nameplate rating of the a > lternator. The GA spam-can community> > >really blew it when 60A b-lead bre > akers were installed in 100,000+> > >aircraft with 60A alternators.> >> >Ea > sily solved by sizing the CB properly. I guess they don't have> >smart peop > le working for the GA spam-can community. Frankly CB's> >can take slight ov > erloads for a period of time with out a trip. Again> >moot point Bob, if th > e alternator can only put out 45 amps.> > That's what I said. The 60A break > er is too small for> being used with a 60A alternator. Yes, MOST nuisance> > tripping is avoided by the noteworthy time delays> inherent in the design o > f CBs . . . but the majority> of nuisance trips of breakers in light aircra > ft are> the 60A b-lead breaker tied to a 60A alternator.> > Your off-hand c > omment about the intelligence of folks> working in GA is uncalled for and y > et another manifestation> of your long and oft demonstrated history of bell > igerent,> ill-informed, nay ignorant participation on this List.> There are > MANY folks within GA that would very much> like to rectify the condition c > ited . . . but it's never> bubbled to the top-ten-problems list with an air > frame OEM and> the FAA makes it insanely $difficult$ to make even the> simp > lest changes. Hence, this marginal design has> endured for decades more out > of resignation to the> authority of a higher power than of ignorance or ap > athy.> > > > >In my humble opinion, ignoring a lot of experience and> > >th > oughtful reasoning suggesting that panel a mounted, b-lead> > >breaker is n > ot the best-we-know-how-to-do.> > >Bob . . .> >> >What?> >> >Fuses are fine > . Buth with (stock) internal regulation the CB is a good> >reason to use a > B-lead CB. Other engineers have worked on this> >Bob. The pull-able CB for > the B-lead is specified. It's irresponsible of> >you to be so stubborn and > opinionated, making ONE blanked edict> >that one size fits all. Fuses are n > ot a BE ALL solution for every> >application. Follow the manufactures recom > mendation!> > This isn't a fuses/breakers discussion, it's> an examination > of the physics which govern assembly> of some exceedingly simple ideas into > recipes for> success with an acknowledgment of hazards which> should be co > nsidered as part of a thoughtful design.> > >> >In my humble opinion, I dis > agree with Bob with my thoughtful reasoning> >and facts. I don't care what > you use but know why you are using it. I> >don't believe you will have nois > e or won't be able to disconnect the> >b-lead manually if you want to. When > people talk 100's of volts & fire> >they are exaggerating in non-scientifi > c emotional arguments, not> >engineering. Have Bob prove these are real pro > blems. I could come> >up with lots of NIT PICK reasons a fuse really is a p > oor choice.> > George, you have been politely requested to keep> your comme > nts on this topic to yourself . . . they've> been read many times for years > on this List and debunked> as recorded and published at:> > http://www.aer > oelectric.com/articles/gmcjetpilot.html> > http://aeroelectric.com/articles > /The_Truth_about_Crowbar_OV_Protection.pdf> > You have designed nothing, fi > xed nothing, contributed> nothing to the understanding of physics, serviced > no> customers, taught no classes, or offered a 100% satisfaction> assured > warranty for your products. Yet you persist> in lurking at the edges of a s > andbox not of your> construction to throw rocks and mud while hiding behind > > a pseudonym decorated with much alphabet soup of> self proclaimed titles/ > accolades. You claim superior> engineering insight while never having demon > strated> it with useful work-product.> > I've demonstrated/experienced/expl > ained every assertion> I've ever made based on my hands-on experiences with > these> systems since I did my first OV relay design for Cessna> Aircraft i > n 1975. Your belittling diatribes and circular> arguments contribute nothin > g to the advancement of> our science, understanding or art and yet you deig > n to> call me a liar. Your brand of 'science' is not welcome> in this class > room. You sir are the secretive, fraudulent> participant in these discussio > ns and I will ask you> politely for the third or forth time, please go away > .> > Bob . . .> > (---------------------------------------)> ( . . . a long > habit of not thinking )> ( a thing wrong, gives it a superficial )> ( appe > arance of being right . . . )> ( )> ( -Thomas Paine 1776- )> (------------- > ==================> > > > > ________________________________ Message 18 ____________________________________ > > > Time: 07:44:47 PM PST US > From: "Robert L. Nuckolls, III" > Subject: Re: AeroElectric-List: Tefzel cables and d-sub connectors > > > At 06:55 AM 11/21/2007 -0800, you wrote: > > > > >I am have reached the point in my building where I have to address some > >electrical design issues. I need to install the servo for the R.A. Allen > >electric elevator trim tab. The servo has 5 leads, and is supplied with a > >length of 5-conductor Belden 8445 cable to connect to the controls in the > >cockpit. A check on the Internet shows that this cable is PVC insulated > >with 5 22AWG wires. I have a several questions. > > > >1. I was planning to use Tefzel insulated cable as much as possible. Is it > >worthwhile to replace R.A. Allen's PVC insulated cable with Tefzel > >insulated cable? > > > See: > > http://aeroelectric.com/articles/macservo/macservo.html > > > >2. For this application cable would be better than 5 individual wires, > >because the wires must pass outside the skin from the elevator to the > >fuselage. After looking around on the Internet, I was unable to find a > >5-conductor cable with Tefzel wire insulation and a Tefzel jacket. I did > >find a company, TPC Wire, > > > >http://www.tpcwire.com/tpc/pdf/03_TrOxCable_6.pdf, > > > >that sells 100 ft lengths of shielded cable with Tefzel wire insulation > >and a polyurethane exterior cover that should work (part no. 61506). They > >don't have 5 conductor cable, but the 6 conductor cable would not be much > >heavier. Does such a cable look like a reasonable substitute? Are there > >other sources for Tefzel insulated cable that I should consider? > > Run individual 22AWG wires from the connector forward. > The connector as described is light enough to simply > be covered with heat shrink and supported by the cable > assembly, no need to mount it separately. There's no > good reason to treat your trim actuator wires any > differently than a bundle of wires that carry nav, > strobe and antenna wires to the back of the airplane. > > > >3. The servo instructions suggest soldering the cable conductors to the > >servo leads and wrapping the joints with electrical tape. > > It was my first view of a behind the panel rat's nest > of odd pieces of wire and way too much electrical tape > that prompted me to write the first edition of the > 'Connection 21 years ago. > > > I was originally planning to use butt splice crimp connectors instead of > > soldering. I'm now considering using a 9 conductor d-sub plug. Are the > > d-sub plugs a good choice for a remote location, like the elevator? > > Yup, that works. There are some smaller, classier > connectors you could consider too . . . but they're > more expensive, take special tools and don't do > any better job than a d-sub. > > > >4. If one uses a d-sub, should the plug itself be secured to the elevator > >(how?) or would cable ties or an adel clamps on the cable provide adequate > >support. > > Float it on the cable. > > > >5. Also, since TPC Wire has a $100 minumum order, it behooves me to buy > >cable for other uses in the airplane in this one order. E.g., power for > >the nav lights, headlights, etc. One use that I'm considering is to buy > >some 24 conductor cable to pass through the firewall to carry engine > >instrument signals. > > Please don't do this. In over 30 years of > systems design and integration I've never seen > a practical need for multi-conductor bundles > other than those called out as shielded > for the purpose of protecting a signal path. > > Build your bundles one wire at a time. > > > > Which brings me back to the d-sub connectors. Would d-subs be reasonable > > replacement for the terminal strips that I have seen used to connect > > engine instruments to wires passing through the firewall? > > > Sure. > > > Can d-subs handle engine compartment temperatures? > > Yes. > > > Will thermocouple leads crimped into d-sub pins work OK? > > > Yes. Been doing it for years. > > > Are d-subs robust enough to endure the correction of wiring goofs? > > > Depends on how clumsy you are. I've got connectors > in my data acquisition systems where some pins have > been removed/replaced over a dozen times. Be nice to > them and they'll do well for you for a long time. > > Terminal strips are labor intensive, drive up > parts count, use threaded (ugh) fasteners. Crimped > joints into machined pins/terminals are far less > troublesome for maintenance and cost of ownership. > > Bob . . . > > > ________________________________ Message 19 ____________________________________ > > > Time: 08:15:50 PM PST US > From: "Bill Schlatterer" > Subject: RE: AeroElectric-List: Location of battery bus > > Bevan, I am using Z13/8 with the HD Endurance bus plus an Aux Bat and bus > for the EFIS. I tried to shoot a picture at about the same angle as your > picture with the tray down. I personally think it's very easy to get to, > but probably not in flight. My copilot stick is removable, pic attached. > Also Aux Bat and bus under AHRS. Note battery (P212 7ah) is attached below > AHRS. > > Hope this helps, locations work nice for me. > > Bill S > > > _____ > > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of B Tomm > Sent: Wednesday, November 21, 2007 12:14 AM > Subject: RE: AeroElectric-List: Location of battery bus > > > Thanks Bill > > Looks very good. Nice fuse block mount. Can you access it without taking a > control stick out and crawling underneath? Maybe just leaning over sideways > from the pilot seat? > > I see a SD8 ? alternator. Can I assume you've wired up per Z13/8? Just a > guess, correct me if I'm wrong. Based on Bob's comments, I'm thinking that > Z13/8 will be ideal for me. Not sure what size Odyssey batt I need. Have > not completed a load analysis yet. If you are flying yet, I would like to > know what schematic Z drawing you're using and how you like it. > > Bevan > > Attached is a pic of my panel so far. No real wiring done yet. Just making > everything fit. > > _____ > > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bill > Schlatterer > Sent: Tuesday, November 20, 2007 9:21 PM > Subject: RE: AeroElectric-List: Location of battery bus > > > Bevan, this is what I did on my 7a for block locations. Small Tab forest on > FW side to large forest on cabin side. Fuse blocks on the inside are on a > swing down tray. Ran the battery lead to the always hot bus to a fuse slot > which really protects the wrong end of the wire but it seemed better than > nothing (maybe a fusible link on the battery end would be better). Wire is > about 14" from Battery to bus as I remember it but not likely to have a > problem. > > Bill S > 7a > > _____ > > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of B Tomm > Sent: Tuesday, November 20, 2007 3:28 AM > Subject: AeroElectric-List: Location of battery bus > > > Good morning Bob, > > Considering Z-13/20 architecture in an RV7A. The Vans recommended position > for the battery is on the firewall in the engine compartment which I agree > with. That being said, the contactors would be located nearby. Would it > follow that the battery bus should also be located on the engine side of the > firewall and if so, would it be appropriate to use a fuse block style as > we've come to appreciate? In other words, would the fuse block style and > associated faston terminals stand up in the FF environment? I would prefer > to see the fuses inside the cockpit just aft of the firewall (cleaner > environment), but to get to here there would be a little more than 6 inches > of unprotected wire. > > Thanks again. > > Bevan > > > href="http://www.matronics.com/contribution">http://www.matronics.com/chref > "http://www.matronics.com/Navigator?AeroElectric-List">http://www.matronics. > com/Navigator?AeroElectric-List > > href="http://forums.matronics.com">http://forums.matronics.com > > > ________________________________ Message 20 ____________________________________ > > > Time: 08:47:10 PM PST US > From: "Robert L. Nuckolls, III" > Subject: RE: AeroElectric-List: RE: Pullable 60 Amp Breaker > > > At 07:43 PM 11/21/2007 -0600, you wrote: > > > > > > >With several hundred, uh thousands (they become blurred and seemingly > >insignificant) of flight hours I now attempt a life-long goal of building > >my own airplane. My self-professed weakness is wiring, electronics and > >electricity in general. Thus, my reason for joining this forum. I read > >every post with an open mind and hopefully add to my limited understanding > >of the traveling electron. > > > >In following this thread of "Pullable 60 Amp Breaker" I am reminded of > >something I learned a long time ago. The only difference between a jet > >pilot and a jet engine is the fact that a jet engine stops whining when > >you shut it down. > > > It is for folks such as yourself that at least > some among us must go out of their way to protect > the liberties of all against the attacks of a > few. This is the simple-idea that defines > honorable behavior. I (and I'm sure others) > will continue to sift and refine the inventions > to be formed from solid understanding of their > component simple-ideas. You have come to the > right place sir. > > Bob . . . > > > ________________________________ Message 21 ____________________________________ > > > Time: 08:58:23 PM PST US > From: "Robert L. Nuckolls, III" > Subject: Re: AeroElectric-List: Running avionics on power supply > > > At 07:56 AM 11/21/2007 -0500, you wrote: > > > > > > >No replies to my initial post, so trying again.... > > > >Should there be any issues in running my electrical system with a power > >supply instead of the alternater/engine running? I have a battery in the > >circuit (PC680). > >Do I need to connect the power supply directly to the battery or can I > >hook it to my shunt to simulate the power coming from the alternator? > > > >Just want to make sure that I don't fry anything..... > > Some years ago I sold a 13.8 volt, 25A switchmode > power supply along with instructions on how to wire > it to the aircraft such that it emulated the ship's > alternator. This allowed a builder to fire up all but > the heaviest loads on the electrical system and to > exercise all the systems just as if the engine were > running and the alternator was turned ON. > > If you have a well behaved power supply (13.8 volts > preferred, current limited against accidental shorts) > then you can basically hook it up about anywhere. Across > the battery is fine. This makes the battery master > capable of disconnecting your supply from system by > turning the battery master OFF. > > See: > > http://www.mpja.com/prodinfo.asp?number=5386+PS > > also, the various smart-chargers with more robust > outputs like those shown on pages 6 and 7 of: > > http://www.schumacherproducts.com/assets/pdf/sec_catalog.pdf > > can be used. Again, just connect across the battery, > plug into wall and use the battery master for > control. > > Wall-Mart sells several of these models. Get one > with 10A or more capability. > > Bob . . . > > ----------------------------------------) > ( . . . a long habit of not thinking ) > ( a thing wrong, gives it a superficial ) > ( appearance of being right . . . ) > ( ) > ( -Thomas Paine 1776- ) > ---------------------------------------- > > > > > > > > > ________________________________ Message 2 _____________________________________ Time: 07:52:39 AM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Question about Relays/Switches Scott R. Shook wrote: > Are those suitable for our applications? I am just not certain I want to > entrust tens of thousands of dollars of my airplane and its ESSENTIAL BUS to > a $9 relay. > I'm trusting many thousands of dollars and six years of building time to several pieces of 3/8" steel tube that cost only a few dollars each. Your electronics stack if full of components that will go belly up if it looses a $.03 resister or diode. What happens if a $2 valve stem breaks? Step back a moment and think about it. Eliminating a component from consideration because it isn't expensive enough is just silly. Is the thing engineered properly to handle the intended job or not. If the relay works flawlessly in an automobile, it will work just as well in reasonably similar conditions (ie, an airplane). ________________________________ Message 3 _____________________________________ Time: 08:04:46 AM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Running avionics on power supply JOHN TIPTON wrote: > > > Likewise: I have a CB power supply (13.8v 3amp) which I thought of > using to power up the system - to the vacant battery terminal or where? > I've been using a surplus computer power supply to test my installation. The yellow wires are a very well regulated 12V. The blue wire has to be tied to one of the black wires. Black is ground. It will only deliver a few amps, and will shut itself down if overloaded, which I consider a feature since it will keep me from frying anything in many cases. ________________________________ Message 4 _____________________________________ Time: 03:40:57 PM PST US From: "RV Builder (Michael Sausen)" Subject: RE: AeroElectric-List: Re: Matt's Profiteering (not) I realize that this thread is a bit stale but hey, what else is there to do while loosening the belt on Thanksgiving other than checking email lists that you are behind on. :-) Ernest I know you are a geek like many of us but you are a bit behind in the economics of email nowadays. I do large scale email systems design (20k to 100k+ users and 3-4 in a year) and I can tell you for a fact the infrastructure to do this isn't cheap. While you may think email is multicast, and in a perfect world it would be, the reality is RFC's aren't always followed as intended. In many cases only the connection may be constant assuming the emails are queued up in order, and each email to each user is sent individually. While not always CPU intensive (except for directory lookups and keeping a connection open), emails on this volume produce a crap load (technical term) of IO at the disks and it takes some serious hardware to keep from killing a disk subsystem or causing major queue backups. I believe this was the reason for the last couple of upgrades Matt completed. Spam has already been covered but I just wanted to add that any commercial service such as this is usually targeted heavier than a normal business. Look, I get it. Some people think they are owed a service and try to rationalize not paying for it when asked for a donation to the idea that they really aren't getting a valued service or that it costs someone like Matt nothing to do this. Hey tell yourselves whatever you want to make you feel better about it. No skin off my back. But in a world of $40 a month phone bill, $60 a month cell service, $75 a month cable/sat, $40 - $80 for Internet, and on and on. I find it funny people would be all that concerned about someone making a couple bucks for running a service that gives us the equivalent of $100 an hour consulting for free. Don't underestimate what we have here. But hey it's a free country and anyone who feels this service isn't worth the effort can always go to Yahoo (supported by ads at the bottom of every email unlike this one) or that other RV "college fund" site that bombards the hell out of you with ads and might as well have a popup with every click asking for a donation. I think Matt does a great job. I think his system of asking for a donation one month a year is more than fair (NPR you listening?) and I think each person out there has every right to decide if they don't want to make a donation and I'm willing to bet the vast majority of us don't. What I would like to see is if you don't want to, or even if you did, that you keep disparaging comments to yourselves. This isn't a public company and we are not owed financial statements. It's supported at a best level of effort and, given the number of service restoration teams I have been on over the years, I think it's been outstanding so far. Sorry Ernest, I'm really not trying to take a shot at you, and I think you are a valued member of this list, I just don't want people to get the impression this is easy to do because it just isn't fair to Matt. Off my high horse and do not archive for that $0.00013 of disk space this 14KB message costs to archive. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Ernest Christley Sent: Wednesday, November 14, 2007 8:56 AM Subject: Re: AeroElectric-List: Re: Matt's Profiteering (not) Werner Schneider wrote: > > > And Ernest do not forget, your numbers are the mails coming in, but > how many 1000 users has the server to send out mail to? I think that > might account for most of the traffic over the needed link. > > I could tell you from another list server, due to a heavy SPAM attack > I've not got ANY mail since 7 days I can only read them currently over > the web interface as the message fwd is shutdown since a week. > > and do not archive The first concern is a red herring, because SMTP doesn't work that way. The protocol is inherently multicast. If there are 100 users on one mail server, it will send out one message, and the SMTP server that the users share will duplicate the message on the recieving end. The larger ISPs use several techniques to insure that all the incoming mail comes through one server address (even if it isn't a single physical server) so that the multicast features of SMTP are optimized. A dumpster dive computer with a residential broadband connection could handle all the *normal* list traffic we're discussing. The connection would be the bottleneck. The computer would have enough bandwidth left over for a decent game of Doom2. The spam is a valid concern. With the system we have (SMTP) the only way to do anything at all about it is to pre-send headers and dump anything that isn't from a valid/registered user that is subscribed to a list. Unfortunately, that requires cooperation from people that don't want to cooperate. The job is analogous to standing in no-man's land trying to sort bullets from enemy machine gun fire. It'd be nice if the enemy would label their bullets, and stop shooting the ones that you don't like. 8*) I ran my server several years ago, and it seems that the spam problem is growing exponentially. ________________________________ Message 5 _____________________________________ Time: 06:38:17 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Question about Relays/Switches At 10:49 AM 11/22/2007 -0500, you wrote: > > >Scott R. Shook wrote: >>Are those suitable for our applications? I am just not certain I want to >>entrust tens of thousands of dollars of my airplane and its ESSENTIAL BUS to >>a $9 relay. >> >I'm trusting many thousands of dollars and six years of building time to >several pieces of 3/8" steel tube that cost only a few dollars each. >Your electronics stack if full of components that will go belly up if it >looses a $.03 resister or diode. What happens if a $2 valve stem breaks? > >Step back a moment and think about it. Eliminating a component from >consideration because it isn't expensive enough is just silly. Is the >thing engineered properly to handle the intended job or not. If the relay >works flawlessly in an automobile, it will work just as well in reasonably >similar conditions (ie, an airplane). I've spent most of a career associated with and often directly with a process called failure mode effects analysis or FMEA for short. The process calls for studying a system schematic and going through it part by part deducing the effects of any expected failure. For example, resistors may go open (usually because of bad connection or physical damage) but they don't go shorted. They also don't change value in profound ways. They may drift out of precise calibration but a 47K resistor doesn't suddenly become a 33K resistor. This is the process that must be conducted to determine how any circuit (discrete components or integrated circuits) to decide what the ramifications are for any probable failure mode. Once those modes are deduced, then depending on hazard levels for those failures, a statistical study for failures/flight hour may be conducted to see what measures should be put into place to (1) reduce risk to airframe and occupants and/or (2) reduce risk cost of ownership. In the case of a relay used to handle the e-bus alternate feed, yes . . . relays are among the LEAST reliable devices you can put into a system. This is why I expressed a good bit of concern for this electrically dependent engine installation and the numbers of relays incorporated. See: http://www.aeroelectric.com/Pictures/Misc/Too_Many_Relays.jpg This installation was in serious need of some re-design for simplification. Having said that, modern automotive relays are exceedingly robust and seldom troublesome in our cars. So . . . The question to be asked and answered in this conversation is, "Does failure of a plain- vanilla automotive relay pose risk of hazard for any given flight?" Given that we're talking about a failure tolerant design, the answer should be "no". Indeed, the e-bus is fitted with two, independent power sources and routes. Further, the e-bus should drive only those devices needed for minimum energy sustenance of devices needed for en-route operations. If one of those systems is necessary for comfortable termination of flight, then a backup for that system should be installed . . . and wired to the main bus. The point here is that architecture and parts selection should be driven more by the big picture for failure modes and propose missions for the aircraft. The perceived or real "quality" of a device should be more of a cost of ownership issue than a safety issue. Bob . . . ------------------------------------------------------------------------------------- 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.