---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 08/05/12: 13 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:19 AM - Re: Starter contactor leaking voltage (user9253) 2. 07:50 AM - Re: Starter contactor leaking voltage (Eric M. Jones) 3. 07:52 AM - Re: Re: Starter contactor leaking voltage (Robert L. Nuckolls, III) 4. 10:36 AM - Re: Re: Extending thermocouple leads (Richard E. Tasker) 5. 11:56 AM - Re: Re: Starter contactor leaking voltage (Mickey Coggins) 6. 01:00 PM - Re: Re: Starter contactor leaking voltage (Henador Titzoff) 7. 01:29 PM - Safe Wire Types (jhausch) 8. 02:54 PM - Re: Re: Starter contactor leaking voltage (Robert L. Nuckolls, III) 9. 03:38 PM - Re: Safe Wire Types (Marvin Dorris Jr) 10. 04:11 PM - Avionics Seminar for Builders-Wadsworth, OH-September 8, 2012 (Gary Baker) 11. 05:33 PM - Re: Starter contactor leaking voltage (user9253) 12. 07:37 PM - Re: Safe Wire Types (Robert L. Nuckolls, III) 13. 07:39 PM - Re: Safe Wire Types (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 05:19:49 AM PST US Subject: AeroElectric-List: Re: Starter contactor leaking voltage From: "user9253" Theoretically there should be NO leakage through the starter contactor. But the insulation used in the contactor is not perfect. There could be some insignificant leakage. Digital voltmeters have a very high input impedance which allows them to measure insignificant voltage. Try shorting the output terminal to ground with your fingers of one hand while measuring the voltage. Or use an old analog voltmeter which will give more meaningful measurements in this situation. Or use a very small 12v test lamp, the type used for automotive instrument illumination. I do not think there is enough leakage to worry about. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=380080#380080 ________________________________ Message 2 _____________________________________ Time: 07:50:16 AM PST US Subject: AeroElectric-List: Re: Starter contactor leaking voltage From: "Eric M. Jones" repost As others have mentioned, the problem is in how you use your tools...like the voltmeter. Imagine that you have a voltmeter that is infinitely sensitive (infinite impedance). Now it will measure the battery voltage even thru an open switch. In fact, it will measure 500 volts between your belt buckle and your shoe laces. And the top of your hat will be 1000 volts higher than the soles of your New Balance sneakers. You can actually extract some tiny amount of power this way. So meter impedance is not a lack of quality in a meter, it is a necessary and useful characteristic of the measuring device. And in a solid state circuit (like a diode), there will almost always be a voltage on the output that is similar to the input voltage even when the meter is off. And in fact the "leakage voltage" will not be able to light even the tiniest LED...so ignore it. I once designed a Cmos circuit where somebody (okay, me...) forgot to add the power trace to the IC. Years later, an inquisitive technician, tracing an unrelated fault discovered it, but all the shipped product had worked just fine. So just don't make voltage measurements like this. See attached for a better way. -------- -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=380088#380088 Attachments: http://forums.matronics.com//files/diode_test_745.pdf ________________________________ Message 3 _____________________________________ Time: 07:52:19 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Starter contactor leaking voltage New question (yes, I'm building very slowly) - I have the Van's starter contactor (Part Number = ES 24021) and when I apply 12v to the battery connection, I get about 0.4v on the starter connection. =C2 This is before it is energized. =C2 When I apply the 12v to the 'S' terminal, I get the full 12v on the starter terminal. Is it normal for some voltage to "leak" even when the device is "idle"? =C2 My battery contactors don't do this, and I don't have another starter contactor to test with. Thanks, Mickey At 07:18 AM 8/5/2012, you wrote: Theoretically there should be NO leakage through the starter contactor. But the insulation used in the contactor is not perfect. There could be some insignificant leakage. Digital voltmeters have a very high input impedance which allows them to measure insignificant voltage. Try shorting the output terminal to ground with your fingers of one hand while measuring the voltage. Or use an old analog voltmeter which will give more meaningful measurements in this situation. Or use a very small 12v test lamp, the type used for automotive instrument illumination. I do not think there is enough leakage to worry about. Joe My thoughts exactly. This thread illustrates a measurement conundrum that has existed since day one in the study and diagnosis of electron flow. The ideal measurement technique should be transparent to quantities being explored. The earliest precision voltmeters (ammeters with resistors in series) were excellent demonstrations of the best-we-knew-how-to-do at the time. Emacs! Note the label at the bottom of the scale=plate that says "1000 ohms per volt". This is another way of saying that this instrument has a basic sensitivity of 1 milliampere full scale and when making a reading on the 150 volt scale, the instrument presents a "load" to the circuit being measured of 1000 x 150 or 150,000 ohms. It will "draw" 1 milliampere of current from the measurement node at 150 volts. These instruments were a grade trade off between sensitivity, accuracy, linearity and calibration drift due to temperature and age. But an instrument like this is fitted with a 'mirrored scale'. The observer lines up the pointer with the reflection of the pointer so as to drive parallax error to zero. This instrument could be both read and relied upon for readings with certainty of 1% or better. If you had measured the "output" from your open starter contactor with such a device, no doubt the reading would be zero . . . and commensurate with your expectations. The day I got hired into Boeing (at $86/week) I went down to Interstate Electronics and bought a Triplett 630 multimeter. It was a 20,000 ohm/volt instrument (50 microamp movement) and exemplary technology for run-of-the-mill bench test instruments. It replaced a 1000 ohm/volt meter that somebody had given me some 5 years earlier. I still have the 630. It was 20 times more sensitive than the earlier instrument and offered accuracies on the order of 2%. But no doubt the Triplett would also say that your contactor was working as expected. Such devices were useless for many investigations into the function of vacuum tubes. The source impedance of many voltages of interest were so high that probing the node with this voltmeter would also show zero volts . . . and the circuit under test would cease to function at all. Probing through sensitive circuitry added new requirements for sensitivity and isolation. This was achieved with some form of amplification. A exemplar instrument is shown here: Emacs! This Heathkit product has an input circuit that looks like this: Emacs! Notice the voltage divider of resistors that total up to more than 9 megohms. Notice too a 1 meg resistor built into the probe. The input impedance for this instrument is over 10 megohms. Further, probing a node with a combination of DC volts of interest that also carries some signal (perhaps even high frequency RF) is only very slightly affected by the probe. This instrument is several hundred times more sensitive than the device at the top of the page. This kind of instrument may also have produced an anomalous reading in the de-energized condition. Modern digital voltmeters have input impedances on the order of 20 megohms. Further, they do not provide any isolation for probe-effects when measuring 'busy circuits'. I have crafted a x10 probe for my Fluke multimeter from an low capacity, oscilloscope probe to conduct the kinds of measurements I used to do with my Heathkit VTVM. Also, I have some load resistors I can stack onto the voltmeter's test lead jacks that deliberately degrade instrument sensitivity so that readings are not influenced by small leakages. The point of this soliloquy is to remind us that not all observations provide good data . . . but all data can be filtered through a healthy level of skepticism supported by an understanding of the circuit under test along with the measuring device's limits. Bob . . . ________________________________ Message 4 _____________________________________ Time: 10:36:54 AM PST US From: "Richard E. Tasker" Subject: Re: AeroElectric-List: Re: Extending thermocouple leads You are absolutely correct. In fact, it may not affect the readings at all. The way a thermocouple works is that any given metal will generate a voltage from one end to the other if the temperature is different from one end to the other. If one chooses a different metal for a second wire it will generate a different voltage across its length. If one hooks a meter between the two wires at one end it can be calibrated to read the difference in temperature between the two ends because the sum of the two outputs will vary with temperature. If there is no difference in temperature between the two ends, there is no voltage generated so no temperature reading displayed. You can make all kinds of connections and add other materials between the two ends and you will see no temperature reading as long there is no temperature difference. Taking that one step further, if there is no temperature difference between the each end of the things you add, then, even if there is a temperature difference between the far end (cylinder head) and the meter end, it will still read correctly. So, if a spade connection is the same temperature from end to end (which is pretty likely since they are copper - a very good heat conductor) there will be no net voltage generated across the connection. Which means that the reading you get at the meter (or whatever you are using to read the temperature) will still be the same as if you had no spade connection. Where you would get into trouble is if you add a long splice in the thermocouple wire that is not thermocouple wire. For example if you add several feet of copper wire to your too short thermocouple wire. The likelihood of that being the same temperature at each end decreases in proportion to the length of the extension. Bottom line: You will likely see no difference in reading with or without the spade and pin connections. Dick Tasker Radioflyer wrote: > > The extension (thermocouple) wire pair would eventually connect to an instrument on the panel in the cabin. So, Engine side: thermocouple--spades--J wire pair extension--thru firewall. Then Cabin side: extension cont'd--spades--copper--instrument on panel. The extension is 12 feet long because this is in a pusher aircraft. Spades to copper to instrument because I can't connect the J type thermocouples wires directly to the DB15 on the instrument. > > What I'm thinking is that the parasitic couple between spades and thermocouple wire pair in the hot engine side, and the other parasitic couple of thermocouple wire pair and spades in the cooler cabin will not much affect the absolute temp readings. > > --Jose > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=380062#380062 > > -- Please Note: No trees were destroyed in the sending of this message. We do concede, however, that a significant number of electrons may have been temporarily inconvenienced. -- ________________________________ Message 5 _____________________________________ Time: 11:56:12 AM PST US From: Mickey Coggins Subject: Re: AeroElectric-List: Re: Starter contactor leaking voltage Joe, Eric, Bob, Thanks so much for the feedback - I tried the lamp, and of course it did not light up. Also used an older analog instrument, and it showed no indication of voltage. Thanks to your help and a bit of time reading up on impedance, I have a better understanding what is happening here. I'm really happy to have run across this "problem" as it allowed me to learn some new stuff. Thanks again! Regards, Mickey On Sun, Aug 5, 2012 at 4:51 PM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > New question (yes, I'm building very slowly) - I have the Van's starter > contactor (Part Number = ES 24021) and when I apply 12v to the battery > connection, I get about 0.4v on the starter connection. =C3=82 This is be fore it > is energized. =C3=82 When I apply the 12v to the 'S' terminal, I get the full > 12v on the starter terminal. > > Is it normal for some voltage to "leak" even when the device is "idle"? =C3=82 > My battery contactors don't do this, and I don't have another starter > contactor to test with. > > Thanks, > Mickey > > At 07:18 AM 8/5/2012, you wrote: m > > > > Theoretically there should be NO leakage through the starter contactor. > But the insulation used in the contactor is not perfect. There could be > some insignificant leakage. Digital voltmeters have a very high input > impedance which allows them to measure insignificant voltage. Try shorti ng > the output terminal to ground with your fingers of one hand while measuri ng > the voltage. Or use an old analog voltmeter which will give more > meaningful measurements in this situation. Or use a very small 12v test > lamp, the type used for automotive instrument illumination. > I do not think there is enough leakage to worry about. > Joe > > My thoughts exactly. This thread illustrates > a measurement conundrum that has existed since > day one in the study and diagnosis of electron > flow. The ideal measurement technique should be > transparent to quantities being explored. The > earliest precision voltmeters (ammeters with resistors > in series) were excellent demonstrations of the > best-we-knew-how-to-do at the time. > > [image: Emacs!] > > Note the label at the bottom of the scale=plate that > says "1000 ohms per volt". This is another way of saying > that this instrument has a basic sensitivity of 1 milliampere > full scale and when making a reading on the 150 volt > scale, the instrument presents a "load" to the circuit > being measured of 1000 x 150 or 150,000 ohms. It will > "draw" 1 milliampere of current from the measurement node > at 150 volts. > > These instruments were a grade trade off between > sensitivity, accuracy, linearity and calibration drift > due to temperature and age. But an instrument like > this is fitted with a 'mirrored scale'. The observer > lines up the pointer with the reflection of the pointer > so as to drive parallax error to zero. This instrument > could be both read and relied upon for readings with > certainty of 1% or better. > > If you had measured the "output" from your open starter > contactor with such a device, no doubt the reading would > be zero . . . and commensurate with your expectations. > > The day I got hired into Boeing (at $86/week) I > went down to Interstate Electronics and bought > a Triplett 630 multimeter. It was a 20,000 ohm/volt > instrument (50 microamp movement) and exemplary > technology for run-of-the-mill bench test > instruments. It replaced a 1000 ohm/volt meter > that somebody had given me some 5 years earlier. > I still have the 630. It was 20 times more sensitive > than the earlier instrument and offered accuracies > on the order of 2%. > > But no doubt the Triplett would also say that > your contactor was working as expected. > > Such devices were useless for many investigations into > the function of vacuum tubes. The source impedance of > many voltages of interest were so high that probing > the node with this voltmeter would also show zero > volts . . . and the circuit under test would cease > to function at all. > > Probing through sensitive circuitry added new > requirements for sensitivity and isolation. This > was achieved with some form of amplification. A > exemplar instrument is shown here: > > [image: Emacs!] > > This Heathkit product has an input circuit that > looks like this: > > [image: Emacs!] > > > Notice the voltage divider of resistors that total up to > more than 9 megohms. Notice too a 1 meg resistor built > into the probe. The input impedance for this instrument > is over 10 megohms. Further, probing a node with a > combination of DC volts of interest that also carries > some signal (perhaps even high frequency RF) is only > very slightly affected by the probe. This instrument > is several hundred times more sensitive than the > device at the top of the page. > > This kind of instrument may also have produced an > anomalous reading in the de-energized condition. > > Modern digital voltmeters have input impedances on > the order of 20 megohms. Further, they do not provide > any isolation for probe-effects when measuring 'busy > circuits'. I have crafted a x10 probe for my Fluke > multimeter from an low capacity, oscilloscope probe > to conduct the kinds of measurements I used to do > with my Heathkit VTVM. Also, I have some load resistors > I can stack onto the voltmeter's test lead jacks that > deliberately degrade instrument sensitivity so that > readings are not influenced by small leakages. > > The point of this soliloquy is to remind us > that not all observations provide good data > . . . but all data can be filtered through a > healthy level of skepticism supported by an > understanding of the circuit under test along > with the measuring device's limits. > > ** > > ** Bob . . . > -- Mickey Coggins ________________________________ Message 6 _____________________________________ Time: 01:00:49 PM PST US From: Henador Titzoff Subject: Re: AeroElectric-List: Re: Starter contactor leaking voltage Eric, =0A =0AThis has nothing to do with aviation other than avionics are built with ICs.- I would just like to know how not=0A including the power supply tra ce from pin to circuitry allows the chip circuitry to work as advertised (d atasheet)?- I've never heard of a chip that worked=0A without intended po wer.- Since it was CMOS and CMOS is very =0Aconservative with power, did it somehow derive its power from IO =0Asignals? =0A =0AYou must be an Analog Devices kind of guy. -I worked at Teradyne for s everal years. It was a lot of fun riding the train to South Station every w eekday. Henador Titzoff --- On Sun, 8/5/12, Eric M. Jones wrote: From: Eric M. Jones Subject: AeroElectric-List: Re: Starter contactor leaking voltage et> repost - - - - - - As others have mentioned, the problem is in how you use your to ols...like the voltmeter. - - - - - - Imagine that you have a voltmeter that is infinitely sensitive (infinite impedance). Now it will measure the battery voltage even thru an open switch. In fact, it will measure 500 volts between your belt buckle an d your shoe laces. And the top of your hat will be 1000 volts higher than t he soles of your New Balance sneakers. You can actually extract some tiny a mount of power this way. - - - - - - So meter impedance is not a lack of quality in a meter, it is a necessary and useful characteristic of the measuring device. And in a soli d state circuit (like a diode), there will almost always be a voltage on th e output that is similar to the input voltage even when the meter is off. A nd in fact the "leakage voltage" will not be able to light even the tiniest LED...so ignore it. - - - - - - I once designed a Cmos circuit where somebody (okay, me...) for got to add the power trace to the IC. Years later, an inquisitive technicia n, tracing an unrelated fault discovered it, but all the shipped product ha d worked just fine. - - - - - - So just don't make voltage measurements like this. - - - - - - See attached for a better way. - - - - - - -------- -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=380088#380088 Attachments: http://forums.matronics.com//files/diode_test_745.pdf le, List Admin. ________________________________ Message 7 _____________________________________ Time: 01:29:27 PM PST US Subject: AeroElectric-List: Safe Wire Types From: "jhausch" Ran across this link. Did some searching here to see if posted previously, but that does not seem to be the case. Anyone's thoughts on this? http://www.vision.net.au/~apaterson/aviation/wire_types.htm Read this topic online here: http://forums.matronics.com/viewtopic.php?p=380111#380111 ________________________________ Message 8 _____________________________________ Time: 02:54:24 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Starter contactor leaking voltage At 01:54 PM 8/5/2012, you wrote: >Joe, Eric, Bob, > >Thanks so much for the feedback - I tried the >lamp, and of course it did not light up. Also >used an older analog instrument, and it showed >no indication of voltage. Thanks to your help >and a bit of time reading up on impedance, I >have a better understanding what is happening >here. I'm really happy to have run across this >"problem" as it allowed me to learn some new stuff. Thanks again! > >Regards, >Mickey I've taken this posting to the List and fixed some syntax/spelling issues, converted to a pdf and posted it to AeroElectric.com article archives. The cleaned up document is available at: http://tinyurl.com/8oe5wbj Bob . . . ________________________________ Message 9 _____________________________________ Time: 03:38:23 PM PST US From: Marvin Dorris Jr Subject: RE: AeroElectric-List: Safe Wire Types If you're building a new airplane=2C use TKT Boeing or maybe TKT Airbus. I f you have to fly in something older=2C or something that doesn't have thes e types of wire=2C and something happens=2C blame your aviation safety advi sor if you lose people. And I'm thinking of buying a 1960 Bonanza Debonair?????????? Best Regards to All=2C > Subject: AeroElectric-List: Safe Wire Types > From: jimhausch@gmail.com > Date: Sun=2C 5 Aug 2012 13:28:56 -0700 > To: aeroelectric-list@matronics.com > > > Ran across this link. Did some searching here to see if posted previously =2C but that does not seem to be the case. > > Anyone's thoughts on this? > http://www.vision.net.au/~apaterson/aviation/wire_types.htm > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=380111#380111 > > > > > > > =========== =========== =========== =========== > > > ________________________________ Message 10 ____________________________________ Time: 04:11:28 PM PST US From: "Gary Baker" Subject: AeroElectric-List: Avionics Seminar for Builders-Wadsworth, OH-September 8, 2012 EAA Chapter 846 is pleased to announce that we will host an Avionics Seminar at Wadsworth Skypark Airport Saturday, Sept. 8, beginning at 8 am. This type of avionics program has never been offered in the Cleveland, OH, area and should help increase homebuilders' knowledge in this part of their build. Seating will be limited. Attendees will have the opportunity to meet representatives from Aerotronics, Inc., Garmin, Dynon, Grand Rapid Technologies, TruTrak, and Advanced Flight Systems. In a few cases, the owners of the companies will be attending. Hands-on demos will be available and short workshops will be held throughout the day. Pilots who are already flying and want to see the latest upgrades are also invited to attend. There might also be some pilots who did not build their RV, buying an experienced aircraft, and want a better understanding of all things electrical. This seminar should provide answers for everyone. Aerotronics will be awarding a headset to a lucky winner. Dynon will be giving away a D-1, their new portable EFIS, valued at more than $1,400! The other vendors might be kind enough to offer some sort of door prize as well. For more information and registration, please go to Avionics Seminar - Chapter 846. Let me know if you have any questions. Gary Baker President EAA Chapter 846 www.846.eaachapter.org/ Wadsworth, OH 330-321-6274 cid:image001.gif@01CC886A.15E9B350 ________________________________ Message 11 ____________________________________ Time: 05:33:51 PM PST US Subject: AeroElectric-List: Re: Starter contactor leaking voltage From: "user9253" Many troubleshooters have come to the wrong conclusion when testing a circuit with a voltmeter without the circuit being loaded. The troubleshooter might think, "The voltmeter reads 12 volts. Therefore everything up to this point must be OK." Without a load, that hypothesis could be incorrect. No load means no current. No current means no voltage drop. So a voltmeter will read normal voltage even if there is unwanted high resistance in the circuit. The high resistance could be due to a bad switch or a loose connection or corrosion or whatever. Without current flowing through that resistance, there will be no voltage drop across it. A voltmeter could read normal voltage when no current is flowing in a problem circuit. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=380131#380131 ________________________________ Message 12 ____________________________________ Time: 07:37:42 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Safe Wire Types At 03:28 PM 8/5/2012, you wrote: > >Ran across this link. Did some searching here to see if posted >previously, but that does not seem to be the case. > >Anyone's thoughts on this? >http://www.vision.net.au/~apaterson/aviation/wire_types.htm > > This tempest has been bubbling at various vapor-generation rates for decades . . . I'll begin by noting that there's no such thing as a 'safe' airplane . . . nor any other machine which operates in close proximity to people and other living creatures. Each one is simply a tool that offers certain risks associated with its construction and use. Every one of them, used or maintained carelessly will eat more than your lunch . . . There's little about the construction and operation of a OBAM aircraft to compare with an Air Transport category aircraft. The operation, maintenance, system complexities, and exposure to people-induced mishap have very little if anything in common. Mr. Paterson's heart is in the right place and he's privy to many facts surrounding the history of ATC aircraft. Yes, there have been a goodly number of incidents that had origins with electrically induced fires. How do these relate to your RV7 or even Lancair IVP? Air Transport category flight cycles in US number in tens of thousands per day with about 1.8 millions of souls arriving comfortably at their intended destination. The world wide figures would probably more than double that. What are the numbers of incidents of in-flight fire induced by electrical systems where the fire might have been avoided had the INSULATION been something different? There are many electrical systems issues that arise from damage by shipping containers in the hold, accumulation of lint from carpets and clothes in inaccessible places, drips from coffee makers in the galley and potty plumbing. Accumulation of hydraulic fluids, ingress of rainwater, splash from wheel wells, etc. etc. Those airplanes are operated to maximize revenue generating hours per day while our airplanes spend the overwhelming majority of their time parked. The ATC aircraft will experience more flight hours in a few months than your airplane will over it's lifetime . . . and be exposed to a thousand times more situations with a potential for mishap. Root cause of the majority of accidents in small aircraft do not originate with the electrical system at all . . . much less with the kind of insulation on the wires. There are thousands of airplanes flying with cotton covered rubber insulation popular in 1940, tens of thousands flying with nylon over PVC used for a couple decades worth of Cessna/Piper/ Beech production. Yet these less-than-exotic insulations go unnoticed for their alleged hazard . . . because they are very low risk. I've worked some issues on Hawkers originally certified with some exotic insulations that would arc-track and experienced some electrical events that did not precipitate a serious accident. I'm aware of no incidents involving electrical systems where Tefzel or pre-Tefzel insulation was a factor. In other words, I don't see the incident rates going down because the insulation on the wire is Part 25 qualified. Yes, people who are paid to worry are very good at their jobs. Some folks worry as a hobby or even out of a sense of civic duty. But none of these folks seem to put their work product into perspective for how it defines RISK. Even though there are thousands of airplanes flying with allegedly the worst possible insulation on their wires, what is the probability of any one planeload of folks is going to experience a bad day in the breaker box? There are conditions and forces in the overall flight system that contribute much greater factors to the grand equation that defines risk for failure to arrive comfortably at your intended destination. Further, the risk factors for leaking potty pipes and inattentive baggage handlers don't even figure into the grand equation for an RV. I cannot argue qualitatively with the assertions derived from a study of Mr. Patterson's data. I can refer to the performance history in things like King Airs and Beechjets . . . and my acquaintances who investigate accidents involving those kinds of aircraft. I suggest that probability of insulation failure of a Tefzel wire (or even PVC) is WAAaaayyyy out on some small branch of the system reliability matrix for your airplane. So far out that it's not worthy of investment for either capital or emotional resources. When I climb aboard a CJ and get a look at the cockpit crew who looks like they barely have to shave every day . . . or listen to the thumps and crashes coming from the baggage compartment, concerns for insulation on the ship's wiring do not even enter my mind. Bob . . . ________________________________ Message 13 ____________________________________ Time: 07:39:39 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Safe Wire Types At 05:37 PM 8/5/2012, you wrote: If you're building a new airplane, use TKT Boeing or maybe TKT Airbus. If you have to fly in something older, or something that doesn't have these types of wire, and something happens, blame your aviation safety advisor if you lose people. Hmmm . . . where does one purchase this wire? And I'm thinking of buying a 1960 Bonanza Debonair?????????? How about it ol' Bob. Would you recommend the wire bundles be stripped out and replaced? 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.