---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 12/30/03: 25 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:40 AM - Source for an AIM artificial horizon (Gilles.Thesee) 2. 07:11 AM - Microair 760 intercom (RVEIGHTA@aol.com) 3. 07:27 AM - Re: Manual master switch (Robert L. Nuckolls, III) 4. 07:53 AM - Re: Architecture questions for an RV7 (Robert L. Nuckolls, III) 5. 08:31 AM - Re: Microair 760 intercom (Robert L. Nuckolls, III) 6. 08:37 AM - Re: SD-8 Voltage Regulator Potential (Robert L. Nuckolls, III) 7. 09:21 AM - Re: manual master switches, over-voltage controllers (Gary Casey) 8. 09:50 AM - Manual master switch- OV protection (klehman@albedo.net) 9. 10:33 AM - Re: No Electric Starter/System Ques (Steve Sampson) 10. 10:54 AM - Re: SD-8 Voltage Regulator Potential Overheating (Robert L. Nuckolls, III) 11. 10:58 AM - Re: Manual master switch (Chad Robinson) 12. 11:48 AM - Re: Manual master switch (David Swartzendruber) 13. 12:56 PM - Re: No Electric Starter/System Ques (Robert L. Nuckolls, III) 14. 01:24 PM - Re: Manual master switch (Robert L. Nuckolls, III) 15. 01:27 PM - Terminal Blocks (Darwin N. Barrie) 16. 02:44 PM - Re: Manual master switch- OV protection (Robert L. Nuckolls, III) 17. 03:02 PM - Re: manual master switches, over-voltage controllers (Robert L. Nuckolls, III) 18. 04:58 PM - Re: Re: manual master switches, over-voltage controllers (William) 19. 05:35 PM - Horizontal Contactor (Don Boardman) 20. 05:35 PM - Phone/Mic Jack Connector (Don Boardman) 21. 05:54 PM - Re: Phone/Mic Jack Connector (Larry Bowen) 22. 05:56 PM - OVM (Larry Bowen) 23. 06:23 PM - Re: Phone/Mic Jack Connector (Don Boardman) 24. 07:15 PM - Re: OV module on RV with 60Amp internally-regulated alternator. (Amit Dagan) 25. 08:42 PM - Twisting Fat Wires (Don Boardman) ________________________________ Message 1 _____________________________________ Time: 05:40:08 AM PST US From: "Gilles.Thesee" Subject: AeroElectric-List: Source for an AIM artificial horizon --> AeroElectric-List message posted by: "Gilles.Thesee" Hi Bob and all, Does anyone know of a reliable source for a used AIM 1100 electric artificial horizon (14 V, tilt preferably 4.5) ? Any info appreciated. Thanks, Gilles Thesee ________________________________ Message 2 _____________________________________ Time: 07:11:16 AM PST US From: RVEIGHTA@aol.com Subject: AeroElectric-List: Microair 760 intercom --> AeroElectric-List message posted by: RVEIGHTA@aol.com Bob/all: The built-in intercom of my Microair 760 transceiver is so noisy at normal cruise speeds that It's almost impossible to carry on a conversation with my passenger. The radio is installed in an RV-8A which is notoriously noisy. I recently purchased a Softcom intercom which comes with a wiring harness. Several wires from the intercom ( mic key, headset audio and mic audio) go to the radio, while the other wires are to connect to the headphone & mic jacks. Since I already have the jack wired up, using your wiring harness and wiring diagram, will I need to rewire the jacks using the wiring provided with the intercom? By the way, none of the IC jack wires are shielded. Any suggestions are appreciated...... Walt Shipley ________________________________ Message 3 _____________________________________ Time: 07:27:59 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Manual master switch --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:24 AM 12/29/2003 -0500, you wrote: >--> AeroElectric-List message posted by: klehman@albedo.net > >Gary you've brought some of my thoughts to the surface which is usually >dangerous. The pros of a manual switch seem to be no holding current and >a bit of security/theft protection if it is hidden or at least not on >the panel. > >Well it turns out that the massive but low cost metal unit sold by >Summit racing (and even cheaper at my local farm supply) is actually >heavier than an electric contactor. > >Flaming River make some that look to be composite and lighter. One sells >for around US$80. complete with an 18" remote handle extension. Another > version has a removeble plastic key. However it is easier to provide >security with a small switch or in other ways. > >If I hard wire my battery to the starter, same as when my car engine was >in its first life, then it seems that there is no particular need for a >large contactor anyway. A small 40 amp relay (or even two for >redundancy) would suffice for killing power to the distribution system. >And even they won't kill battery bus power to my two efi and ignition >computers. What do you do if the starter contactor sticks? How do you drive all the fat wires to "max cold" in anticipation of an unplanned arrival with the earth? >Anyway I'm having trouble justifying the need for a battery contactor or >manual switch. Seems it wouldn't really kill power to very much of my >aircraft for crash protection etc. and I'd need one for each of two >batteries. Then there is the starter contactor which doesn't seem to add >much protection either. There are a lot of car fires but the heavy >battery to starter wire doesn't seem to be a problem in those, near as I >can figure. Please correct me if someone believes otherwise. Bob has >mentioned in the archives that he prefers to use a starter contactor >even with automotive starters like mine. Fewer connectors and lower >resistance between the alternator, battery, and starter is attractive >though. How much is "fewer" and "lower" in comparison with the total and how would you perceive the difference if you had no prior knowledge of what "more" and "higher" was? >Ok this is already long (which I hate to do as it tends to discourage >comments) but I might as well mention my 40 amp ND internal voltage >regulator alternator and my 20 amp John Deere PM alternator. Both have >been fitted with large pulleys to slow them and help limit max current >output. Do I add two more contactors for over voltage protection? Why did you cripple some perfectly good alternators? What is the advantage of slowing down an alternator that runs most happily at high rpm? The BIG downside for generators was low output at idle and taxi RPMs but if you put a smaller pulley on them, the brushes would wear faster. When alternators came along, all the downsides went away but you have brought them back . . . >Well I'll load the PM alternator with always on lights/strobes and >perhaps a fuel pump. Do I really care if it runs away and stuffs a few >extra amps into the battery till I can get on the ground? Are you planning to call the runaway condition an "emergency" or a "maintenance event"? An airplane fitted with sufficient controls, notification of failure and options for alternative operating modes means that which drive the pucker factor up in spam-can pilots is no big deal for an OBAM aircraft pilot. > An old flooded >battery would warm up and vent some electrolyte and shrug it off. Not >sure about a small RG battery. I need to be informed about the regulator >failure but I'm not as convinced that I need an active OV protection >contactor here. It could be done with a small 40 amp relay or the one >B&C sells though. > >The 40 amp ND alternator was chosen for both weight and so that a >regulator failure would not result in a hundred amps being available as >in the car. Don't understand. A runaway alternator is never capable of delivering lots of amps over and above the nameplate rating. They are ALL capable of delivering lots of volts . . . 100 or more in cruise rpm with the small pulley of choice. This is what ov protection is about. > Of course any voltage spikes have to be lower too with a >small unit. Define "spike", where it's generated. How long does it last and how much energy does it contain? This term is stirred into every worried discussion about electrical systems with complete lack of understanding about what it is, where it comes from and how a system may be configured so that for the most part it will not exist. In the world of cookie-cutter certified ships and FAA approved flight schools, pilots have neither the knowledge or the options of using their knowledge to improve the machines they fly. None the less, many of our brethren in the OBAM aircraft community carry this baggage with them into the world where the finest aircraft to have ever existed are built. >OV protection is probably a good idea here though since I am >planning to use small batteries and the efi will only stand so much ov. >Since we are thinking out of the box a bit, what about a normally open >relay that adds say 30 amps of load to that alternator in the event of >an ov. How about shutting off the offending alternator in case of an ov condition? > Switch in an electric windshield defroster or car heater perhaps? >That would control the ov situation but still leave enough power >available to run my engine for an unlimited time without even bothering >to switch to my redundant efi system powered from the PM alternator. And >a relay failure would only disable the ov protection whereas an ov >contactor failure or activation would kill the alternator output. Such >an approach also avoids extra connectors in the wire between the >alternator and battery. What is the service history of "extra connectors" between the alternator and battery. How many connections have you had to repair on your automobile or any other vehicle? Suppose a lead between the alternator becomes disconnected, how is this any more likely or how is the result any different than a wire coming unhooked in the regulator or somewhere else in the system so as to make the alternator unusable? Would it not be better to design your system for "failure tolerance" . . . a system that offers a plan-b alternative to failure of ANY component? >Seems I might still want one heavy duty crossfeed contactor for engine >starting if I use two small batteries but those batteries actually cost >more than one large and one small battery... Cost is secondary here >though. Or it looks like my PM alternator will probably run fine with a >large capacitor and ov protection instead of a small battery... Instead of taking an egg beater to the experience base of that which has gone before us, may I suggest that you consider the suite of z-drawings and find one that most closely matches your perceived needs. Let then consider together how that system falls short. It may be that some modification of the architecture described is in order . . . or perhaps even a new architecture is called for. Let's discuss your perceptions of worrisome events and sort them into two piles: (1) ol' mechanic's tales/hangar legends and (2) real threats which we'll address by considered design and mitigating operating techniques. The goal is to configure a system about which you have NO worries and an operating philosophy that virtually guarantees that you complete a leg of a mission all the way to airport of intended destination without breaking a sweat. I'm confident that you'll find that many of your concerns are not founded upon good science and once you understand how your system of choice works, your confidence level will raise markedly. More important, your system reliability (of which the pilot is a critical component) will stand head-and-shoulders above that of certified aviation. Bob . . . ________________________________ Message 4 _____________________________________ Time: 07:53:28 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Architecture questions for an RV7 --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:47 PM 12/29/2003 +0000, you wrote: >Bob, > >I am building an RV 7 using all B&C electrical products, including >the 60A alternator and 20A vacuum pad mounted alternator and >SB1-14 and LR3C-14 voltage regulators. The architecture includes >a separate battery master switch and individual alternator field >switches. (I am using one of your main bus/essential bus architectures >with dual alternators, diode feed to the essential bus and alternate >switched path to the essential bus. This arrangement is as shown in >skeleton figure 17-2 of your Aero Electric Connection manual >rev 10 dated Nov 2001). First, why are you installing two big alternators? How do you plan to use this airplane and how is it going to be equipped? For this combination of alternators, Figure Z-14 is the system of choice for folks who NEED this much engine generated power. >I have what seems like a trivial question: If I have a main bus >fault for example, is there any importance as to the order of >opening/closing the battery master and essential bus switches. >If not why can't the essential bus alternative feed switch be >replaced by a direct connection? If I close the essential bus feed >switch by accident whilst the battery master switch is still closed >are there any implications? "Faults" to the bus are so rare as to be unworthy of procedural consideration. The philosophy of the architecture in Figure 17-2 (and Z-11) is to provide (1) an alternative feed path for power to electrically powered items that will essentially insure comfortable arrival at airport of intended destination and (2) provide a way to reduce en route loads during battery only operation to a value that compliments goal (1) cited above. If you have two engine driven power sources in the form of 40+ and 20A machines, en route energy conservation is not an issue. Therefore, it seems more practical to consider figures 17-5 and Z-14. But first things first, why have you selected this particular pair of alternators? >Apologies if the following questions should be addressed to B&C I am not >sure of their e-mail address? > > >If I open the battery master switch without opening the alternator field >switches first, will this have any detrimental effect on the alternators? If wired per any of the Z-figures with a 2-10 master switch, this issues is mute. The switch is configured to bring the alternator on last and off first. Unless you've specifically designed and tested your proposed system for alternator only performance, operation without a battery is an iffy proposition and not recommended. >Are there any other circumstances when using your voltage regulators and >alternators that can damage either of them by incorrect operation of the >battery master switch and/or the individual field switches. For example, >by opening a field switch with the engine running and the battery master >switch closed ? I should perhaps mention that I am asking this question >because there are dire warnings in some Automobile maintenance manuals, >and indeed on an American Web site dealing with some marine installations, >that an engine must on no account be run without the battery being >connected else alternator damage may ensue as a result of a rise of output >voltage to 100V or so. But this advice may not apply to your arrangements ? It sure does . . . that's what drove the configurations described in Appendix Z. >I plan to use the battery temp sensors on both regulators. This option is >not shown on the SB1-14 regulator. Is this available and if so are the >connections to pins 1&6 as per the LR3C-14 No, the temperature sensor is useful in very few situations and not recommended unless you plan to spend long legs of a trip at 25,000 feet on oxygen where you might cold-soak a battery. >I want to keep my instrument panel as neat as possible! I have >standardised all my warning and indicator lights as high intensity LEDs >with internal dropping resistors. Can I use one of these in place of your >supplied low voltage warning filament lamp on the LR3C-14? Yes, see http://www.aeroelectric.com/temp/LV_Led.jpg >I am also planning to be able to test all the warning lamps on my panel >with a single push to test button, applying a ground or 12v as >appropriate. For the alternator warning lights I was planning on using a >relay to temporarily disconnect the low voltage warning light from pin 5 >on the regulator and connect to ground therefore placing 12v from the main >bus across the light to test its operation. Is this ok? If you're using LEDs throughout, I wouldn't bother about PTT. The life of an LED is so high that you're MUCH more likely to loose functionality of an annunciator for reasons that are not tested by your PTT system. Keep the parts count down and check list shorter by leaving this low-value feature off. I will invite you to join us on the AeroElectric List to continue this and similar discussions. It's useful to share the information with as many folks as possible. A further benefit can be realized with membership on the list. There are lots of technically capable folks on the list who can offer suggestions too. You can join at . . . http://www.matronics.com/subscribe/ Thanks! Bob . . . -------------------------------------------- ( Knowing about a thing is different than ) ( understanding it. One can know a lot ) ( and still understand nothing. ) ( C.F. Kettering ) -------------------------------------------- ________________________________ Message 5 _____________________________________ Time: 08:31:11 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Microair 760 intercom --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:10 AM 12/30/2003 -0500, you wrote: >--> AeroElectric-List message posted by: RVEIGHTA@aol.com > >Bob/all: The built-in intercom of my Microair 760 transceiver is so noisy at >normal cruise speeds that It's almost impossible to carry on a conversation >with my passenger. The radio is installed in an RV-8A which is notoriously >noisy. A hot mic intercom depends on GOOD noise cancelling microphones unless you use the intercom push-to-talk feature. If you have the ptt feature in place, the 760's intercom feature will be no better/worse than any system. >I recently purchased a Softcom intercom which comes with a wiring harness. >Several wires from the intercom (mic key, headset audio and mic audio) go to >the radio, while the other wires are to connect to the headphone & mic jacks. > >Since I already have the jack wired up, using your wiring harness and wiring >diagram, will I need to rewire the jacks using the wiring provided with the >intercom? By the way, none of the IC jack wires are shielded. I suggest you wire in accordance with the diagram supplied with the intercom. Bob . . . -------------------------------------------- ( A beginning of the end is marked by ) ( replacement of experience and common ) ( sense with policy and procedures. ) ( R. L. Nuckolls III ) -------------------------------------------- ________________________________ Message 6 _____________________________________ Time: 08:37:42 AM PST US From: "Robert L. Nuckolls, III" Overheating Subject: Re: AeroElectric-List: SD-8 Voltage Regulator Potential Overheating --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" Overheating At 08:35 PM 12/29/2003 -0800, you wrote: >--> AeroElectric-List message posted by: "Scott Diffenbaugh" > > >Hi Bob & fellow Listers, > > Reached the point where I felt comfortable with my total system > design >utilizing Z-13 & was placing the order with Tim at B&C today when the topic >of loading the SD-8 came up. When I indicated I had designed it for 8 amps >or less continuous, Tim informed me the regulator was designed for 2 to 3 >amps continuous and would most likely fry at 8 amps unless some sort of >cooling was provided. If located in the cockpit, it should have additional >heatsinking and a fan would be a good idea, but there could be electrical >noise. If mounted on the firewall in the engine compartment there would be >less noise, but it would need substantial heat sinking, and/or a blast tube. This is a new one on me! I'll have to look into this. > In an earlier response, Bob mentioned if loaded greater than 8 amps >continuous, a heat sink was necessary, or possibly a more robust regulator >like the KeyWest. I Google searched KeyWest and only found one hit, where >someone experienced regulator failure due to overheating with a Rotax & it >also destroyed their alternator. Also was not able to find the KeyWest >website. Anyone have its URL? I've not heard much about Key West lately. It was a really popular regulator for Rotax systems for folks building Pulsars and Kitfoxes and it was mentioned a lot when I belonged to those lists years ago. >Does anyone have experience running the SD-8 continuously at 8 amps? Unless >I have overlooked something, neither the installation instructions for the >SD-8 nor Z-13 mention heat sinks or blast tubes. Am I missing something or >might Z-13 users experience regulator overheating if their main alternators >fail? (according to Tim, the stuff inside the regulator housing starts to >ooze out when overheated) This is a mind-blower . . . there are many hundreds of SD-8's flying as the ONLY source of engine driven power. If they've had problems with regulator performance, I've been unaware of it. Based on this, I've shown the SD-8 as a really useful and reliable second source in Figure Z-13 . . . if this is NOT the case, then I've got a lot of explaining to do to a hundred or more builders who have installed Z-13. Watch this space! >Thank you in advance for your assistance with this issue. I have put my >order on hold until I have a better understanding. Good idea . . . Bob . . . ________________________________ Message 7 _____________________________________ Time: 09:21:06 AM PST US From: "Gary Casey" Subject: AeroElectric-List: Re: manual master switches, over-voltage controllers --> AeroElectric-List message posted by: "Gary Casey" <