---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 08/07/08: 19 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:35 AM - Fw: Serious Incident to Piper PA-34-200T,Reg: EI-CMT,on 7 November 2007, at Shannon CTA, Co Kerry. (Andrew Butler) 2. 04:23 AM - Re: Article from AOPA on Glass EFIS failures (Stucklen, Frederic W UTPWR) 3. 05:33 AM - Re: Re: Article from AOPA on Glass EFIS failures (Chuck Jensen) 4. 06:11 AM - relay wiring question (Jerry Ricciotti) 5. 06:38 AM - Re: Fraudulent Purchase Attampt (Off Topic) (Eric M. Jones) 6. 06:40 AM - Re: Serious Incident to Piper PA-34-200T (Robert L. Nuckolls, III) 7. 07:03 AM - Re: relay wiring question (Robert Borger) 8. 07:07 AM - Re: Re: Article from AOPA on Glass EFIS failures () 9. 07:33 AM - Re: Re: Fraudulent Purchase Attampt (Off Topic) (Robert L. Nuckolls, III) 10. 11:23 AM - Aux Power Socket (ianwilson2) 11. 11:28 AM - Re: Aux Power Socket (Alfio) 12. 11:44 AM - Re: Aux Power Socket (ianwilson2) 13. 12:20 PM - Re: Aux Power Socket (Ivor Phillips) 14. 01:56 PM - Re: AeroElectric-List Digest: 4 Msgs - 08/06/08 (Jeff Page) 15. 02:19 PM - Re: Re: AeroElectric-List Digest: 4 Msgs - 08/06/08 (Harley) 16. 02:30 PM - Re: relay wiring question (Jerry Ricciotti) 17. 04:32 PM - Re: Re: Fraudulent Purchase Attampt (Off Topic) (n801bh@netzero.com) 18. 04:59 PM - SD-20 repairable? (Alan Adamson) 19. 06:35 PM - Re: relay wiring question (Bob White) ________________________________ Message 1 _____________________________________ Time: 03:35:39 AM PST US From: "Andrew Butler" Subject: AeroElectric-List: Fw: Serious Incident to Piper PA-34-200T,Reg: EI-CMT,on 7 November 2007, at Shannon CTA, Co Kerry. Published yesterday by the Air Accident Investigation Unit in Ireland. http://www.aaiu.ie/upload/general/10887-0.pdf Concerns a complete electrical failure aboard a twin Piper on an IFR flight during winter. Safe landing in the end. Thoughts on lessons learned? Andrew. ----- Original Message ----- From: AAIU Subject: Serious Incident to Piper PA-34-200T,Reg: EI-CMT,on 7 November 2007, at Shannon CTA, Co Kerry. Subscriber, The AAIU have published Final Report No. 2008-018 on www.aaiu.ie concerning a Piper PA-34-200T, Reg: EI-CMT, which occurred on 7 November 2007, at Shannon CTA, Co Kerry. It's URL is I concur! "Never enough time to do the job right, but always enough time to do it over again"! Fred Stucklen Sr Software Engineer If you had to identify, in one word, the reason why the human race has not achieved, and never will achieve, its full potential, that word would be "meetings." Time: 05:25:52 PM PST US From: Ernest Christley Subject: Re: Article from AOPA on Glass EFIS failures Hinde, Frank George (Corvallis) wrote: > > Ahh yes...As I tell my engineers who want every cool gadget going on their sysytems..."Every component is an expensive point of failure" > > It's not a disease in the high-tech industry. It's a pandemic. You ask for a simple function to do a specific simple job. You get back several thousand lines of code with a dozen optional parameters and a slew of hidden side effects (for the uninitiated: unrelated things are changing that you don't expect). Software is a funny thing in that it is very easy to change. This leads to a mentality of "throw it at the wall, and let's keep what sticks". I don't know the veracity of the reports about all the displays going out on the airliners, but my experience tells me that it is very likely. I've seen code be approved by "professionals" that wouldn't pass muster in a freshman college class, and the argument is always that "we don't have time to fix it". If it passes QA (that also doesn't have time to fix anything), then it is shipped. Proper software engineering requires the same sort of methodical, tedious system review and modularity that we expect to put in our electrical design. In the end, that is exactly what it is, a lot of tiny electrical switches going off all over the place. The fault scenarios are often difficult to identify. Even people who should know better often forget this. -- http://www.ronpaultimeline.com ________________________________ Message 3 _____________________________________ Time: 05:33:32 AM PST US Subject: RE: AeroElectric-List: Re: Article from AOPA on Glass EFIS failures From: "Chuck Jensen" We let our customers do all of our beta testing. :-) Chuck Jensen -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Stucklen, Frederic W UTPWR Sent: Thursday, August 07, 2008 7:22 AM Subject: AeroElectric-List: Re: Article from AOPA on Glass EFIS failures I concur! "Never enough time to do the job right, but always enough time to do it over again"! Fred Stucklen Sr Software Engineer If you had to identify, in one word, the reason why the human race has not achieved, and never will achieve, its full potential, that word would be "meetings." Time: 05:25:52 PM PST US From: Ernest Christley < echristley@nc.rr.com> Subject: Re: Article from AOPA on Glass EFIS failures Hinde, Frank George (Corvallis) wrote: > > Ahh yes...As I tell my engineers who want every cool gadget going on their sysytems..."Every component is an expensive point of failure" > > It's not a disease in the high-tech industry. It's a pandemic. You ask for a simple function to do a specific simple job. You get back several thousand lines of code with a dozen optional parameters and a slew of hidden side effects (for the uninitiated: unrelated things are changing that you don't expect). Software is a funny thing in that it is very easy to change. This leads to a mentality of "throw it at the wall, and let's keep what sticks". I don't know the veracity of the reports about all the displays going out on the airliners, but my experience tells me that it is very likely. I've seen code be approved by "professionals" that wouldn't pass muster in a freshman college class, and the argument is always that "we don't have time to fix it". If it passes QA (that also doesn't have time to fix anything), then it is shipped. Proper software engineering requires the same sort of methodical, tedious system review and modularity that we expect to put in our electrical design. In the end, that is exactly what it is, a lot of tiny electrical switches going off all over the place. The fault scenarios are often difficult to identify. Even people who should know better often forget this. -- http://www.ronpaultimeline.com ________________________________ Message 4 _____________________________________ Time: 06:11:58 AM PST US From: "Jerry Ricciotti" Subject: AeroElectric-List: relay wiring question I am looking for the proper way to wire my battery and starter contactor. I have a Spruce bought battery contactor, which is a White-Rodgers Type 70 DC power contactor. I expected to see two large posts and two small posts on the unit but it has only one small post. The manufactures web site refers to this as a "Terminal Type 3B - Coil Common to Load" . I want to confirm how to properly wire this to my DPDT master switch, the manufacturers diagram shows a pig tail to the small post from large post that is connected to battery positive. I assume I wire from that large post to the master switch and the back to small post on the contactor. There is no connection from the master switch to ground in this case? Part 2 I have B&C starter relay, it also has only one small post. I assume that it is grounded through it's own case and I should bring positive line through the starter switch and back to the small post and then pig tail a ground wire from the case mounting bolt to the firewall ground? Thanks in advance for your help. Jerry ________________________________ Message 5 _____________________________________ Time: 06:38:33 AM PST US Subject: AeroElectric-List: Re: Fraudulent Purchase Attampt (Off Topic) From: "Eric M. Jones" In the hope that even one vendor will be saved from this, I relate my recent experience with a guy who wanted to buy some large quantity of my stuff and tried to scam me. But, even though I was born in the morning, I wasn't born THIS MORNING. Be careful out there. > Dear Eric, > Thanks for the total quote of my order.The total cost of my order is quite correct and okay by me and I'm ready to pay the bills . I shall inform my freight forwarder who will be coming to pick up the order to hold on and come immediately you inform me that the items are ready for pick up then i can give you a call on that day to get the items packed for pick up and they will call you on their arrival at your address.Also I want you to help me Charge another $230.00 from my card for the freight forwarder who will be coming to pick up my ordered items from you. > > The $230.00 that will be sent to the freight forwarder is for the shipping of my order and other items i ordered from different part of the country which is to be picked up by him and should be deducted from my credit card.Also, I'm compensating you with the sum of $90.00 for the transfer fee and for your efforts. Please note that i should have given the shipping agency my credit card for him to deduct the freight charges but he told me that he doesn't have the facilities to charge or debit credit card , so that's why i bring my vote of confidence in you and i want you to assist me in this measure, so i want you to transfer the funds to him after you have make the charges and the money charged from my credit card is in your account,then you can now make the transfer to the agent via western union.i will have love to do this my self but there are no western union here around me cos i am out of town to monitor my estate construction at a remote village,So the charges you'll make on my credit card will be: > > Order Fee: $450.00 > Agent fee with shipping fare: $230.00 > Transfer Fee plus Your Compensation: $90.00 > Total: $770.00 > > I await your quick response. > Kind Regards > > Terry Gilson C & H Store Inc > > 67 Whitbread Street, Taree, NSW, 2430, Australia > > Phone +61 8 9467 5956, Fax (08) 9439 5544 > > Email:candhstoreinc@gmail.com So I'll be taking a bogus credit card and handing a box of stuff to some yokel in a car? Never to be seen again. I especially like the smooth tip-off "$90 for the transfer fee and for your efforts". "...this guy is going to offer to bet you that he can make the jack of spades jump out of this brand-new deck of cards and squirt cider in your ear. But, son, do not accept this bet, because as sure as you stand there, you're going to wind up with an ear full of cider." ---Guys and Dolls -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones@charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=197105#197105 ________________________________ Message 6 _____________________________________ Time: 06:40:48 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Serious Incident to Piper PA-34-200T At 10:33 AM 8/7/2008 +0000, you wrote: >Published yesterday by the Air Accident Investigation Unit in Ireland. > >http://www.aaiu.ie/upload/general/10887-0.pdf > >Concerns a complete electrical failure aboard a twin Piper on an IFR >flight during winter. Safe landing in the end. > >Thoughts on lessons learned? > >Andrew. This is an interesting case. While the symptom was not repeated by experiment (difficult and hazardous) the deduction drawn by the investigators is quite plausible. There is only one error in the data which is the 0.3 ohm contact resistance cited for the contactor specification . . . this is probably 0.3 MILLIOHMS. Obviously, a contactor with 300 milliohms resistance would be useless. If one tracks the history of system evolution for aircraft, the first time this airplane (or it's ancestors) flew, it was fitted with generators. Generators are noteworthy for their ability to function without benefit of external power for excitation support. The history of the 6041 series contactors in aircraft and throughout industry has been exemplary. However, they DO have a service life and they do WEAR OUT at some point in time. http://aeroelectric.com/Pictures/Failures/6041_Contactor_Failure.jpg The MTBF study offered up in the report spoke to "three failures" . . . of course, these were failures that generated noteworthy incidents such as the case under study. There were thousands of failures for both battery and starter contactors where the difficulty was discovered on the ground or the contactor was teamed with generators and the in-flight failure of a battery contactor did not generate a reportable incident. This is a GREAT example of how architecture, selection of components, and plan-a/plan-b operating procedures can utilize seemingly pedestrian components in a way that failures are simply maintenance events as opposed to reportable events (where there was risk of bending an airplane or occupants). It was consideration of vulnerabilities demonstrated by various components that evolved the Z-figures. First with addition of the e-bus in Z-11. Had the case study airplane been fitted with an e-bus, they would not have needed to resort to cell phone communications or augering around in clouds sans electronic nav aids. The next step was independent, cross-feed electrical systems, Z-14. Obviously a giant step above any of the intertwined architectures that fly in the majority of GA aircraft. I'm aware of NO production aircraft that features such an architecture. The shift to all electric panels vacated the vacuum pump pad. A second engine driven power source could utilize the vacated pad and offer up a three layer system illustrated in Z-11. (1) Battery only + e-bus (2) battery + e-bus supported by 8A engine driven power source holding the battery in reserve for approach to landing and (3) full up battery + e-bus + main bus supported by ships normal alternator. With the advent of the SD-20 offered into GA aircraft and Z-12 architecture, they can come close to a Z-11 configuration . . . but there is still the specter of battery contactor failure that could generate a total loss of system under certain conditions. We were able to address that issue on the Cessna 337 when for a short time there was a small battery pack of flashlight cells and a push button offered up to kick-start a stalled alternator. Later, we took a 3-phase rectifier off the tach generator to provide a source of voltage for the same purpose. Decades later, we're finding alternators that either by accident or on-purpose design have enough residual rotor magnetism to come on line self-excited. Given the speed at which we rotate little automotive alternators in belt-driven applications, it may be that most of those installations will come up without a battery . . . if lightly loaded. Certainly, there are little features we could explore but without a broad spectrum of purposeful design amongst the field of suitable alternators, it's not likely that we'll be able to recommend exploitation of this quality . . . hence the configuration the z-figures as presently published. Is there value in combing through these reports? Certainly. There is (1) the potential for making us aware of previously undiscovered/unconsidered failure modes and (2) re-enforcement of our confidence in the state of our art in crafting failure tolerant systems. The sad part is the regulatory hurdles that prevent our brothers on the TC side of the house from exploiting the simple pleasures of electrical system confidence we enjoy on OBAM aircraft. Present trends plotted out into the future do not suggest they will ever be beneficiaries of such freedoms. Bob . . . ________________________________ Message 7 _____________________________________ Time: 07:03:39 AM PST US From: Robert Borger Subject: Re: AeroElectric-List: relay wiring question Jerry, The 12 volt cable from the battery to the battery contactor also provides the power to the contactor. You run a wire from the single small terminal to your master switch and another wire from the master switch to ground. The master switch then provides ground to complete the circuit and activate the contactor. The starter relay requires that 12 volts be supplied to the small terminal for the relay to activate. Yes, ground is through the case. If your aircraft is composite or tube and fabric construction then you should run a ground wire from the case mount bolt to the firewall ground block. If your aircraft is aluminum ground should be available directly from the airframe. I hope this helps, Bob Borger Europa XS, Rotax 914, Airmaster C/S prop http://www.europaowners.org/N914XL On Thursday, August 07, 2008, at 08:27AM, "Jerry Ricciotti" wrote: >I am looking for the proper way to wire my battery and starter contactor. > >I have a Spruce bought battery contactor, which is a White-Rodgers Type 70 DC power contactor. I expected to see two large posts and two small posts on the unit but it has only one small post. The manufactures web site refers to this as a "Terminal Type 3B - Coil Common to Load" . I want to confirm how to properly wire this to my DPDT master switch, the manufacturers diagram shows a pig tail to the small post from large post that is connected to battery positive. I assume I wire from that large post to the master switch and the back to small post on the contactor. There is no connection from the master switch to ground in this case? > >Part 2 >I have B&C starter relay, it also has only one small post. >I assume that it is grounded through it's own case and I should bring positive line through the starter switch and back to the small post and then pig tail a ground wire from the case mounting bolt to the firewall ground? > >Thanks in advance for your help. > Jerry ________________________________ Message 8 _____________________________________ Time: 07:07:27 AM PST US From: Subject: RE: AeroElectric-List: Re: Article from AOPA on Glass EFIS failures ---- Chuck Jensen wrote: > We let our customers do all of our beta testing. :-) > > Chuck Jensen > You work for Microsoft!? 8*) That's one of my favorite quotes, that I use when I'm getting to the end of my frustration quota with 'managers' that are just being dumb. "Hell, just ship it. The customers will ALWAYS tell us what's wrong with it." ________________________________ Message 9 _____________________________________ Time: 07:33:08 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Fraudulent Purchase Attampt (Off Topic) At 06:36 AM 8/7/2008 -0700, you wrote: > >In the hope that even one vendor will be saved from this, I relate my >recent experience with a guy who wanted to buy some large quantity of my >stuff and tried to scam me. But, even though I was born in the morning, I >wasn't born THIS MORNING. Be careful out there. > I get several requests per year to confirm that I can take orders paid for by Visa or MC to be shipped to Nigeria or some such remote place . . . when my website clearly states that we do process charge cards. A number of these inquiries ask me to acquire merchandise that is not even offered on the website . . . but clearly available from dozens if not hundreds of sites elsewhere on the 'net. You are quite justified in your suspicions. On a trip to Brazil some years ago, I watched a DC6 being unloaded of PT-6 engines and $millions$ of other goodies. The location was on a ramp at a well known aircraft manufacturer. It was illegal to deal in dollars for external trade . . . but the local currency was running about 500% per year inflation . . . essentially worthless. The government choose to 'overlook' these flights between Florida and Brazil where the plane came in with much needed parts to keep the workers employed, and flew back with literally $millions$ in suitcases full of dollars! Drop your customer a note telling him that his courier is most welcome to pick up the shipment if he first hands you a fist full of dollars! It's the way honorable criminals conduct themselves! Bob . . . ________________________________ Message 10 ____________________________________ Time: 11:23:20 AM PST US Subject: AeroElectric-List: Aux Power Socket From: "ianwilson2" Is there a convention for which of the 2 terminals in an Aux/cigar lighter port goes to + or -? I'm currently wiring my Aux power socket and wondered what everyone else does. I can't seem to find anything definite on whether to wire the centre pin or the outside pin to the +. Does it actually matter? Thanks in advance. Ian Read this topic online here: http://forums.matronics.com/viewtopic.php?p=197164#197164 ________________________________ Message 11 ____________________________________ Time: 11:28:39 AM PST US Subject: AeroElectric-List: Re: Aux Power Socket From: "Alfio" Yes it matters. Center pin is positive. You'll note that the pin that is off-center will be shorted to the case of the receptacle, which in turn would be shorted in the panel. You would quickly know you wired it wrong. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=197167#197167 ________________________________ Message 12 ____________________________________ Time: 11:44:41 AM PST US Subject: AeroElectric-List: Re: Aux Power Socket From: "ianwilson2" Thanks Alfio. Good job I checked. It never ceases to amaze me that these things can be produced and not labeled, assuming that everyone knows what they're doing - clearly wrong in my case! Ian Read this topic online here: http://forums.matronics.com/viewtopic.php?p=197169#197169 ________________________________ Message 13 ____________________________________ Time: 12:20:33 PM PST US From: "Ivor Phillips" Subject: RE: AeroElectric-List: Aux Power Socket The standard convention is Positive + to the centre pin and Negative - to the outside body or pin, Yes it definitely matters! Ivor -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of ianwilson2 Sent: 07 August 2008 19:19 Subject: AeroElectric-List: Aux Power Socket Is there a convention for which of the 2 terminals in an Aux/cigar lighter port goes to + or -? I'm currently wiring my Aux power socket and wondered what everyone else does. I can't seem to find anything definite on whether to wire the centre pin or the outside pin to the +. Does it actually matter? Thanks in advance. Ian Read this topic online here: http://forums.matronics.com/viewtopic.php?p=197164#197164 ________________________________ Message 14 ____________________________________ Time: 01:56:12 PM PST US From: Jeff Page Subject: AeroElectric-List: Re: AeroElectric-List Digest: 4 Msgs - 08/06/08 > I'll have to talk to Tom and Brad . . . my short > visit with them last year left me with an impression > of much smarter-than-average-bears. I'd like to believe > their product is equal to or better than DO-160 qualification > recommendations for aircraft. > > Of course, you could call them too! I would expect a "sales" answer to a call like this :-( An outsider who has seem the schematics and heard the behind the scenes stories can usually provide the more truthful answer I am looking for. I had a lot of trouble with the intercom on my Cessna last year. It turned out that the headset used the mic bias voltage to power the audio amplifier. After reverse engineering much of the intercom circuitry, I was appalled at the design. Although it was a 4 place intercom, the co-pilot circuitry "borrowed" some of the pilot's circuitry during transmit. So the pilot lost mic bias voltage and the audio disappeared whenever the co-pilot transmitted. No problem when normal headsets were used with the intercom and no problem when these headsets were used with other intercoms. Yuck. The headset manufacturer was very forthcoming with the design details necessary for me to figure this out. The intercom manufacturer (including the president) absolutely insisted there was nothing wrong with the design of the intercom. They were very helpful swapping out my intercom for another to confirm it was functioning correctly, but that did not fix the problem of course. Having finally solved it, I encouraged the intercom manufacturer to at least make all their tech support people aware of this issue, since with the number of those intercoms in the field and the popularity of the headsets being sold, the problem would certainly be an issue for others. They treated this like an unusual case that concerned no one else. Based on this, I am hesitant to purchase a new audio panel for my Tundra from this very popular intercom manufacturer. What if the same guy designed this product too ? Jeff Page Dream Aircraft Tundra #10 ________________________________ Message 15 ____________________________________ Time: 02:19:12 PM PST US From: Harley Subject: Re: AeroElectric-List: Re: AeroElectric-List Digest: 4 Msgs - 08/06/08 Afternoon, Jeff... >>I would expect a "sales" answer to a call like this :-( << Excuse me for inserting my two cents here, but I think I have something to offer as well. I doubt very much that you would get a salesmen's type of reply to any call you make to Brad. Tom and Brad ARE Emagair ... not salesmen or support staff. Even though, come to think of it, they also ARE salesmen AND the support staff. And the designers, and the technicians...well you get the picture. A more helpful and knowledgeable couple of guys I've never run across with any company. They would not pull any punches or give you any false information about their products. No one, either in their company or users, knows their products better than they do, and in this case, I relying on information from "An outsider who has seem the schematics and heard the behind the scenes stories" would not be as informed or helpful as Brad would be. Excellent company to do business with... As far as user stories, I think there are some here in the archives if you want to search for them...maybe also in the Canard-Aviators Yahoo group, if you belong to that as well. Harley Dixon (biased...2 P-mags ) ------------------------------------------------------------------------ Jeff Page wrote: > >> I'll have to talk to Tom and Brad . . . my short >> visit with them last year left me with an impression >> of much smarter-than-average-bears. I'd like to believe >> their product is equal to or better than DO-160 qualification >> recommendations for aircraft. >> >> Of course, you could call them too! > > I would expect a "sales" answer to a call like this :-( > An outsider who has seem the schematics and heard the behind the > scenes stories can usually provide the more truthful answer I am > looking for. > > I had a lot of trouble with the intercom on my Cessna last year. It > turned out that the headset used the mic bias voltage to power the > audio amplifier. After reverse engineering much of the intercom > circuitry, I was appalled at the design. Although it was a 4 place > intercom, the co-pilot circuitry "borrowed" some of the pilot's > circuitry during transmit. So the pilot lost mic bias voltage and the > audio disappeared whenever the co-pilot transmitted. No problem when > normal headsets were used with the intercom and no problem when these > headsets were used with other intercoms. Yuck. > > The headset manufacturer was very forthcoming with the design details > necessary for me to figure this out. The intercom manufacturer > (including the president) absolutely insisted there was nothing wrong > with the design of the intercom. They were very helpful swapping out > my intercom for another to confirm it was functioning correctly, but > that did not fix the problem of course. > > Having finally solved it, I encouraged the intercom manufacturer to at > least make all their tech support people aware of this issue, since > with the number of those intercoms in the field and the popularity of > the headsets being sold, the problem would certainly be an issue for > others. They treated this like an unusual case that concerned no one > else. > > Based on this, I am hesitant to purchase a new audio panel for my > Tundra from this very popular intercom manufacturer. What if the same > guy designed this product too ? > ________________________________ Message 16 ____________________________________ Time: 02:30:53 PM PST US From: "Jerry Ricciotti" Subject: Re: AeroElectric-List: relay wiring question Thanks for the reply A comment and an additional question. I noticed the battery contactor only works with the large post opposite the small post connected to positive and does not work with the other large post connected to positive (i.e.. flip flopping the positive) This does not seem to be the case for the starter contactor, it seems to work with either post connected to positive. Is there a reason for this? ----- Original Message ----- From: "Robert Borger" Sent: Thursday, August 07, 2008 10:01 AM Subject: Re: AeroElectric-List: relay wiring question > > Jerry, > > The 12 volt cable from the battery to the battery contactor also provides > the power to the contactor. You run a wire from the single small terminal > to your master switch and another wire from the master switch to ground. > The master switch then provides ground to complete the circuit and > activate the contactor. > > The starter relay requires that 12 volts be supplied to the small terminal > for the relay to activate. Yes, ground is through the case. If your > aircraft is composite or tube and fabric construction then you should run > a ground wire from the case mount bolt to the firewall ground block. If > your aircraft is aluminum ground should be available directly from the > airframe. > > I hope this helps, > Bob Borger > Europa XS, Rotax 914, Airmaster C/S prop > http://www.europaowners.org/N914XL > > On Thursday, August 07, 2008, at 08:27AM, "Jerry Ricciotti" > wrote: >>I am looking for the proper way to wire my battery and starter contactor. >> >>I have a Spruce bought battery contactor, which is a White-Rodgers Type 70 >>DC power contactor. I expected to see two large posts and two small posts >>on the unit but it has only one small post. The manufactures web site >>refers to this as a "Terminal Type 3B - Coil Common to Load" . I want to >>confirm how to properly wire this to my DPDT master switch, the >>manufacturers diagram shows a pig tail to the small post from large post >>that is connected to battery positive. I assume I wire from that large >>post to the master switch and the back to small post on the contactor. >>There is no connection from the master switch to ground in this case? >> >>Part 2 >>I have B&C starter relay, it also has only one small post. >>I assume that it is grounded through it's own case and I should bring >>positive line through the starter switch and back to the small post and >>then pig tail a ground wire from the case mounting bolt to the firewall >>ground? >> >>Thanks in advance for your help. >> Jerry > > > ________________________________ Message 17 ____________________________________ Time: 04:32:18 PM PST US From: "n801bh@netzero.com" Subject: Re: AeroElectric-List: Re: Fraudulent Purchase Attampt (Off Topic) Very easy to fight... Just take a lerge box,,, fill it with packing pean uts,seal it up and tape the crap out of it so it takes forever to open. Hand the guy the box while biting your tonque so you don't laugh so hard . Off he goes with 'Nothing".. Better yet, call the local police, and ha ve them waiting for this guy..... There is a great chance he is wanted f or other stuff too... do not archive wanted to buy some large quantity of my stuff and tried to scam me. But, even though I was born in the morning, I wasn't born THIS MORNING. Be c areful out there. > Dear Eric, > Thanks for the total quote of my order.The total cost of my order is q uite correct and okay by me and I'm ready to pay the bills . I shall in form my freight forwarder who will be coming to pick up the order to ho ld on and come immediately you inform me that the items are ready for pi ck up then i can give you a call on that day to get the items packed fo r pick up and they will call you on their arrival at your address.Also I want you to help me Charge another $230.00 from my card for the freigh t forwarder who will be coming to pick up my ordered items from you. > > The $230.00 that will be sent to the freight forwarder is for the ship ping of my order and other items i ordered from different part of the c ountry which is to be picked up by him and should be deducted from my c redit card.Also, I'm compensating you with the sum of $90.00 for the tra nsfer fee and for your efforts. Please note that i should have given th e shipping agency my credit card for him to deduct the freight charges but he told me that he doesn't have the facilities to charge or debit cr edit card , so that's why i bring my vote of confidence in you and i wa nt you to assist me in this measure, so i want you to transfer the fund s to him after you have make the charges and the money charged from my c redit card is in your account,then you can now make the transfer to the agent via western union.i will have love to do this my self but there are no western union here around me cos i am out of town to monitor my e state construction at a remote village,So the charge! s you'll make on my credit card will be: > > Order Fee: $450.00 > Agent fee with shipping fare: $230.00 > Transfer Fee plus Your Compensation: $90.00 > Total: $770.00 > > I await your quick response. > Kind Regards > > Terry Gilson C & H Store Inc > > 67 Whitbread Street, Taree, NSW, 2430, Australia > > Phone +61 8 9467 5956, Fax (08) 9439 5544 > > Email:candhstoreinc@gmail.com So I'll be taking a bogus credit card and handing a box of stuff to some yokel in a car? Never to be seen again. I especially like the smooth ti p-off "$90 for the transfer fee and for your efforts". "...this guy is going to offer to bet you that he can make the jack of s pades jump out of this brand-new deck of cards and squirt cider in your ear. But, son, do not accept this bet, because as sure as you stand ther e, you're going to wind up with an ear full of cider." ---Guys and Dol ls -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones@charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=197105#197105 ======================== =========== ======================== =========== ======================== =========== ======================== =========== ____________________________________________________________ Physical Therapy Certification Training - Save online. Click now. http://thirdpartyoffers.netzero.net/TGL2241/fc/Ioyw6i4vHJTfM2VjKIzHTXTwg LORZcCwYXGypeElZLtZogawtCDCnX/ ________________________________ Message 18 ____________________________________ Time: 04:59:24 PM PST US From: "Alan Adamson" Subject: AeroElectric-List: SD-20 repairable? I had a secondary buss failure in the last couple of day. Tracked it back to the alternator and SD-20. After some simple debugging, I decided to see if I could see anything move inside it when I turned the engine over by hand. While the ratio is pretty small, I could detect no movement. Further I found that the cooling fins that I could see where moveable with a simple small pointy tool inserted in the back of the unit while it was still attached to the engine. Long story short, after removal, I found that the input spline shaft was intact (all of it's teeth there), but it freely spins and it's obvious that it's not attached to the central armature of the SD-20 any longer. Are these things serviceable? I called B&C, but no tech people until Monday due to travel back from OSH. Thot I'd ask here? Thanks in advance, Alan Adamson Atlanta, Ga ________________________________ Message 19 ____________________________________ Time: 06:35:22 PM PST US From: Bob White Subject: Re: AeroElectric-List: relay wiring question Hi Jerry, The reason is on the starter relay, the coil is activated by a positive voltage to the small terminal and the case is grounded. It has nothing to do with the large terminals. On the contactor, one side of the coil is connected to one of the large terminals (BAT). The other side is connected to ground through the master switch. If you connect the large terminals backwards, then one side of the coil is NOT connected to the battery and you can't activate the coil. You have to get 12V across the coil to activate the contacts on both devices. Look at the attached drawing and it should be easy to see why you can't switch the large terminals on the contactor. Bob W. On Thu, 7 Aug 2008 17:27:51 -0400 "Jerry Ricciotti" wrote: > > Thanks for the reply > > A comment and an additional question. > I noticed the battery contactor only works with the large post opposite the > small post connected to positive and does not work with the other large post > connected to positive (i.e.. flip flopping the positive) > This does not seem to be the case for the starter contactor, it seems to > work with either post connected to positive. > > Is there a reason for this? > > > ----- Original Message ----- > From: "Robert Borger" > To: > Sent: Thursday, August 07, 2008 10:01 AM > Subject: Re: AeroElectric-List: relay wiring question > > > > > > Jerry, > > > > The 12 volt cable from the battery to the battery contactor also provides > > the power to the contactor. You run a wire from the single small terminal > > to your master switch and another wire from the master switch to ground. > > The master switch then provides ground to complete the circuit and > > activate the contactor. > > > > The starter relay requires that 12 volts be supplied to the small terminal > > for the relay to activate. Yes, ground is through the case. If your > > aircraft is composite or tube and fabric construction then you should run > > a ground wire from the case mount bolt to the firewall ground block. If > > your aircraft is aluminum ground should be available directly from the > > airframe. > > > > I hope this helps, > > Bob Borger > > Europa XS, Rotax 914, Airmaster C/S prop > > http://www.europaowners.org/N914XL > > > > On Thursday, August 07, 2008, at 08:27AM, "Jerry Ricciotti" > > wrote: > >>I am looking for the proper way to wire my battery and starter contactor. > >> > >>I have a Spruce bought battery contactor, which is a White-Rodgers Type 70 > >>DC power contactor. I expected to see two large posts and two small posts > >>on the unit but it has only one small post. The manufactures web site > >>refers to this as a "Terminal Type 3B - Coil Common to Load" . I want to > >>confirm how to properly wire this to my DPDT master switch, the > >>manufacturers diagram shows a pig tail to the small post from large post > >>that is connected to battery positive. I assume I wire from that large > >>post to the master switch and the back to small post on the contactor. > >>There is no connection from the master switch to ground in this case? > >> > >>Part 2 > >>I have B&C starter relay, it also has only one small post. > >>I assume that it is grounded through it's own case and I should bring > >>positive line through the starter switch and back to the small post and > >>then pig tail a ground wire from the case mounting bolt to the firewall > >>ground? > >> > >>Thanks in advance for your help. > >> Jerry > > > > > > > > > > > > > -- N93BD - Rotary Powered BD-4 - http://www.bob-white.com 3.8 Hours Total Time and holding Cables for your rotary installation - http://roblinstores.com/cables/ ------------------------------------------------------------------------------------- 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.