---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 08/09/08: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:19 AM - Re: BnC Continuous Duty Contactor 12 v (Joe) 2. 09:25 AM - Re: BnC Continuous Duty Contactor 12 v (Robert L. Nuckolls, III) 3. 01:25 PM - Re: Alternator part number? (Robert L. Nuckolls, III) 4. 04:16 PM - need a tool spec on vacation (Bill Boyd) 5. 06:15 PM - Re: need a tool spec on vacation (Allen Fulmer) 6. 06:24 PM - Re: I-Phone Inclinometer (Eric M. Jones) ________________________________ Message 1 _____________________________________ Time: 08:19:34 AM PST US From: "Joe" Subject: Re: AeroElectric-List: BnC Continuous Duty Contactor 12 v Jeff wrote:"I am using it as a battery contactor but with a Very High out alternator, 200amps ..... So I am thinking I need to find a bigger contactor ? or my other thought - guess was maybe to run TWO Stancor 70-902 contactors in parallel ? with the extra wires also... but concern here is that something I haven't thought of will smoke something if both are not closed ? Maybe I am overlooking a simple cheaper solution...." Jeff,The size of the alternator has nothing to do with the current rating of the battery contactor. The ampacity of the battery contactor should be determined by the engine starting current and by the battery charging current. These two currents are the only significant currents normally flowing through the battery contactor. Even if you have a very large load such as an electric cockpit heater, that current would flow directly from the alternator to the heater without going through the battery contactor. Just because the alternator is rated at 200 amps does not mean that it will be supplying that much. The alternator will only be putting out that current which is needed to operate the loads that are turned on, most likely only a fraction of the alternator's ampacity. I would use the same battery contactor regardless of the alternator size.Joe Gores ________________________________ Message 2 _____________________________________ Time: 09:25:29 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: BnC Continuous Duty Contactor 12 v At 11:16 AM 8/9/2008 -0400, you wrote: >Jeff wrote: > >"I am using it as a battery contactor but with a Very High out alternator, >200amps ..... So I am thinking I need to find a bigger contactor ? or my >other thought - guess was maybe to run TWO Stancor 70-902 contactors in >parallel ? with the extra wires also... but concern here is that something >I haven't thought of will smoke something if both are not closed ? Maybe I >am overlooking a simple cheaper solution...." Interesting! Help us understand a bit more about your proposed system. Under what conditions would you expect your 200A alternator to deliver this kind of power. In other words, what design goals for the vehicle drove the selection of this size machine? > > >Jeff, > >The size of the alternator has nothing to do with the current rating of >the battery contactor. The ampacity of the battery contactor should be >determined by the engine starting current and by the battery charging >current. These two currents are the only significant currents normally >flowing through the battery contactor. Even if you have a very large load >such as an electric cockpit heater, that current would flow directly from >the alternator to the heater without going through the battery >contactor. Just because the alternator is rated at 200 amps does not mean >that it will be supplying that much. The alternator will only be putting >out that current which is needed to operate the loads that are turned on, >most likely only a fraction of the alternator's ampacity. I would use the >same battery contactor regardless of the alternator size. > >Joe Gores Joe is quite correct. The battery contactor must CARRY, not SWITCH starting currents that include some bodacious inrush currents. Then it must CARRY, not SWITCH the battery recharge currents and/or expected battery discharge currents during alternator-out operations. The 80-amp, lowly 70 series devices have given good service. But let's be sure that we're not giving you marginal advice. Do you also plan a big battery? If the battery is "up-sized" in concert with a larger alternator, then it follows that your system MIGHT be capable of extra- ordinary stress on the battery contactor . . . like recharging a big battery with you 200A energy source. There are some up-sized contactors not the least of which are the 586 series devices from Stancor. http://aeroelectric.com/Mfgr_Data/Contactors/Stancor-WhiteRogers/Stancor_586-Series.pdf . . . but we don't have enough information about your design goals to make confident recommendations. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 3 _____________________________________ Time: 01:25:28 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Alternator part number? At 05:27 PM 8/8/2008 -0500, you wrote: > > >At 03:04 PM 8/8/2008 -0400, you wrote: >>On the way back from Oshkosh to Florida my alternator died (lasted 2 >>years). Switched off the main bus and ran the E bus all the way home >>(thanks Bob N.). It was a 35 amp externally regulated part >>#14184. Anyone out there know what the part number is for the same type >>of alternator except in 55 amp unit externally regulated? > > I'm wondering if that was originally an externally regulated > unit. There's a lot of not terribly favorable traffic that > comes up on a Google search about that part number as a Van's > supplied alternator. There's a 'stock', probably internally > regulated version offered on Ebay right now: Followup: Another member on the List has turned me on to the following website: http://www.motorcarparts.com/catalog.htm This link takes you to a YMME selection form that may not be of much use in researching alternators. However, stick anything in, like 2000 Honda Accord with 2.3L engine. Then click on "alternator" for that car. This takes you to a cool screen that offers specs and a 3-view for the alternator. Moreover, there's a box on this page for inserting another part number. Pun in your 14184 number and we get an 35A EXTERNALLY regulated ND alternator with three photographic views. Now we know a lot more about the alternator that started this thread. We also know about an information resource that many of you will find valuable in identifying and perhaps integrating certain kinds of alternators into your projects. This website also offers a technical bulletin against that alternator which speaks to the need to retain the b-lead filter capacitor from your old alternator when replacing it with a new one. It also identifies the functionality the rear mounted receptacle. Pretty cool stuff. Bob . . . ________________________________ Message 4 _____________________________________ Time: 04:16:49 PM PST US From: "Bill Boyd" Subject: AeroElectric-List: need a tool spec on vacation I'm at the beach and Tower informs me my transponder has quit working (again!) I am 99% sure from past trouble with this thing that I can fix it by removing, cleaning and reinstalling the Garmin adapter in the Narco tray, but need a foot-long Allen wrench to reach in there, and don't have it with me. One can buy most anything at the beach these days, but I need the size to look for at the hardware store: what is the dimension of the hex screw that holds radios in avionics trays? 3/32"? Thanks for the help. I'm sure they'll let me back out of the class D with an inop transponder, but it's just not right having stuff not functioning. -Stormy / Bill B. ________________________________ Message 5 _____________________________________ Time: 06:15:55 PM PST US From: "Allen Fulmer" Subject: RE: AeroElectric-List: need a tool spec on vacation 3/32 is correct. Allen -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Bill Boyd Sent: Saturday, August 09, 2008 6:13 PM To: rv-list@matronics.com; aeroelectric-list@matronics.com Subject: AeroElectric-List: need a tool spec on vacation I'm at the beach and Tower informs me my transponder has quit working (again!) I am 99% sure from past trouble with this thing that I can fix it by removing, cleaning and reinstalling the Garmin adapter in the Narco tray, but need a foot-long Allen wrench to reach in there, and don't have it with me. One can buy most anything at the beach these days, but I need the size to look for at the hardware store: what is the dimension of the hex screw that holds radios in avionics trays? 3/32"? Thanks for the help. I'm sure they'll let me back out of the class D with an inop transponder, but it's just not right having stuff not functioning. -Stormy / Bill B. Checked by AVG - http://www.avg.com 9:02 AM ________________________________ Message 6 _____________________________________ Time: 06:24:49 PM PST US Subject: AeroElectric-List: Re: I-Phone Inclinometer From: "Eric M. Jones" Or that Saint Christopher medal on a chain you hang from your compass now. -------- 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=197619#197619 ------------------------------------------------------------------------------------- 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.