---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 02/04/04: 48 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:21 AM - Re: OV protection for internally regulated alternators (Robert L. Nuckolls, III) 2. 07:25 AM - Re: Converting a Denso Alternator (Mark Steitle) 3. 07:31 AM - Re: shunt switch (Joel Harding) 4. 07:33 AM - Re: Noise (Robert L. Nuckolls, III) 5. 07:42 AM - Antenna(S) for Com(s)? (N27160@aol.com) 6. 08:27 AM - start up/shut down procedure (Rick Johnson) 7. 09:08 AM - Re: Antenna(S) for Com(s)? (Robert L. Nuckolls, III) 8. 09:13 AM - Re: Antenna(S) for Com(s)? (Wayne Berg) 9. 10:49 AM - Re: Re: OV protection for internally regulated alternators (Clay R) 10. 11:10 AM - Re: Internally regulated alternators (Robert L. Nuckolls, III) 11. 11:12 AM - Connector for elevator trim servo (N67BT@aol.com) 12. 11:13 AM - Re: start up/shut down procedure (Robert L. Nuckolls, III) 13. 11:40 AM - Re: start up/shut down procedure (Ned Thomas) 14. 11:56 AM - Re: Re: OV protection for internally regulated alternators / ND alternator (Steve Sampson) 15. 12:02 PM - Re: Antenna(S) for Com(s)? (Dave Morris) 16. 12:07 PM - OV protection for internally regulated alternators (Robert L. Nuckolls, III) 17. 12:07 PM - Re: Re: OV protection for internally regulated alternators (Steve Sampson) 18. 12:11 PM - Re: start up/shut down procedure (Robert L. Nuckolls, III) 19. 12:25 PM - Re: start up/shut down procedure (Matt Prather) 20. 01:25 PM - OBAM ? (Kent Sorensen) 21. 01:27 PM - Re: OBAM ? (BobsV35B@aol.com) 22. 01:32 PM - Re: Re: OV protection for internally regulated (Dj Merrill) 23. 01:40 PM - Alternator Recommendation and Conversions (Ned Thomas) 24. 01:46 PM - Re: OBAM ? (Ageless Wings) 25. 02:09 PM - OV protection for internally regulated alternators (Robert L. Nuckolls, III) 26. 02:21 PM - Re: OV protection for internally regulated alt (Beckman, Rick) 27. 02:23 PM - Re: OBAM ? (Dan Branstrom) 28. 02:24 PM - Re: OBAM ? (Jon Finley) 29. 02:41 PM - Re: OV protection for internally regulated alt (Bartrim, Todd) 30. 03:02 PM - Re: OBAM ? (Dave Morris) 31. 03:37 PM - Re: OV protection for internally regulated alternators (Joe Dubner) 32. 04:11 PM - Re: start up/shut down procedure (AI Nut) 33. 04:11 PM - OV protection for internally regulated alternators (Robert L. Nuckolls, III) 34. 04:25 PM - Re: OBAM ? (Robert L. Nuckolls, III) 35. 04:58 PM - Re: Re: OV protection for internally regulated (Jim Oke) 36. 05:16 PM - BNC bulkhead pass-through connectors (LarryRobertHelming) 37. 06:00 PM - Re: BNC bulkhead pass-through connectors (Dave Morris) 38. 06:10 PM - Re: Converting a Denso Alternator #2 (Charlie Kuss) 39. 06:27 PM - Re: Converting a Denso Alternator #3 (Charlie Kuss) 40. 06:59 PM - Re: Converting a Denso Alternator #3 (Charlie Kuss) 41. 07:41 PM - EMI solution for Dynon? (Dan Checkoway) 42. 07:56 PM - Re: start up/shut down procedure (Robert L. Nuckolls, III) 43. 08:05 PM - OV protection for internally regulated alternators (Robert L. Nuckolls, III) 44. 08:10 PM - Re: Connector for elevator trim servo (Robert L. Nuckolls, III) 45. 08:24 PM - Re: BNC bulkhead pass-through connectors (Richard E. Tasker) 46. 09:01 PM - Re: EMI solution for Dynon? (Robert L. Nuckolls, III) 47. 09:08 PM - Re: EMI solution for Dynon? (Dave Morris) 48. 09:51 PM - Re: Converting a Denso Alternator (Jerzy Krasinski) ________________________________ Message 1 _____________________________________ Time: 07:21:12 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: OV protection for internally regulated alternators --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:15 PM 2/3/2004 -0800, you wrote: >--> AeroElectric-List message posted by: Michel Therrien > >That battery dump damage thing... is this only related >with the alternators from Vans, or any automotive >alternators (including the Nippodensos found in >japanese cars)? > >Is this a certainty that it will fail each time, or is >it once in a lifetime that this will happen? > >Thanks! > >Michel Z-24 has been published for several years. I have to believe there have been a lot of systems installed and are flying. The questions are: (1) how many alternators are subject to this failure because their internal regulators are not rated for the battery-dump stress? (2) how many builders have put their particular alternator "to the test" by cycling the alternator control switch while the alternator was working hard? There are so many variables here that a truly quantitative response to your question cannot be deduced from what we know. I'm not sure which alternator Van's is selling. I THOUGHT it was an ND alternator. Does anyone know? It does take a combination of conditions to trigger the event: (1) relatively old design for built in regulator that is NOT protected from the battery-dump transient. (2) size of the transient is a function of how fast alternator is running and at what load when the connection between b-lead and battery is broken. When fitted with rudimentary electrical system instrumentation (low volts warning light or a voltmeter) there is no practical need or routinely exercised practice that calls for opening the alternator disconnect contactor while the engine is running IRRESPECTIVE of alternator vulnerability. If EVERY airplane I've ever rented over the past 23 years had been vulnerable to this failure mode, I'm 99.9% certain that the mode would not have been triggered while I was using the airplane . . . i.e. I've never had a situation arise where it was valuable or even interesting to operate the switch with the engine running. At the moment, my sense is that given the way MOST of us were taught (or not) on how to operate the airplane, the risks to even vulnerable alternators is quite low. The risk can be driven essentially zero once the magnitude of the transient is characterized and prophylactic measures implemented. At this point in the investigation, it would be a sad thing for a builder to jerk his perfectly working alternator off in knee-jerk response to truthful but poorly quantified warnings from well meaning folks who don't understand the system. Bob . . . ________________________________ Message 2 _____________________________________ Time: 07:25:10 AM PST US From: Mark Steitle Subject: Re: AeroElectric-List: Converting a Denso Alternator --> AeroElectric-List message posted by: Mark Steitle At 07:51 PM 2/3/2004 -0800, you wrote: >--> AeroElectric-List message posted by: Hi There > > >I have a couple of Denso Alternators that I want to convert to >nonregulated alternators. Cameron, I posted this procedure a while back, but couldn't find it in the archives. So, here is the procedure I used to convert my two ND alternators to external regulator mode. Mark ============================================= Bob N. strongly recommends using externally regulated alternators only, or modifying the internal regulator models so as to allow it to be shut down if necessary. (Supposedly, a voltage run-away can happen in a few seconds.) Problem is that the articles I read explaining how to convert the internally regulated alternators to external regulation didn't work. (Did I do something wrong?) I think I have worked out a simpler solution. The objective here is to isolate the field windings from the diode bridge so that the alternator can then be externally controlled. This is how I went about converting my alternators. First I removed the back cover, exposing the diode bridge, regulator assy. and brush holder. Then removed the regulator and brush holder and threw the regulator assy in the trash. Next I removed the brush holder and shaped a little brace from 1/8" phenolic that will support one side of the brush holder and isolate it from the diode bridge. This piece will be about 7/8" x 1/4" with a #8 hole in each end. Do not make this piece out of metal or it will short out the diode bridge. Also make up a jumper wire about three inches long with a ring terminal on each end. One end will attach to the right terminal on the brush holder and the other will attach to the alternator case (gnd.). The other terminal on the brush holder will need a spacer under it to keep everything aligned properly. The left brush will need to have the lead wire un-soldered from the brush holder. The wire comes through the back of the brush holder. Unsolder it there and drill out the hole just a bit to allow a #20 wire with shrink tube to fit snugly through the hole. Solder the #20 wire to the end of the braided wire on the brush. Now we're ready to reassemble the whole thing. Pass the #20 wire through the hole drilled in the brush holder and reinsert the spring and brush. Screw the brush holder back into place, with a spacer washer under the left terminal. The ground wire goes on the opposite terminal. Feed the wire soldered to the brush through a hole in the alternator cover, with a grommet to prevent chaffing. This wire will go to the "F" terminal of the external voltage regulator. I used a generic Ford unit from a mid-seventies model (approx. $10/ea from Auto Zone). The S & A terminals of the regulator tie together and get fed from the alt. switch & 5 amp breaker. The "B" terminal on the alternator goes to the battery contactor. The other terminal on the regulator isn't used. I modified two ND alternators using this method and they both work great. It takes about 30 minutes to do the modifications. All I need to do now is add a crowbar over-voltage protector to each regulator and I'm set to go. Or you can use a B&C voltage regulator with built-in OVP and low-voltage warning. ________________________________ Message 3 _____________________________________ Time: 07:31:13 AM PST US From: Joel Harding Subject: Re: AeroElectric-List: shunt switch --> AeroElectric-List message posted by: Joel Harding On Feb 3, 2004, at 4:45 PM, Robert L. Nuckolls, III wrote: > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > At 12:44 PM 2/3/2004 -0700, you wrote: >> --> AeroElectric-List message posted by: Joel Harding >> >> >> >> I'm looking for a recommendation for a high quality mini switch ( one >> fourth inch throat size) to select between the shunt in my alternator >> line and one in the battery lead, before it enters the volt amp meter. > > Are you running cranking currents through the battery shunt? > > No, it's in the lead from the battery to the ess. bus, so it won't be exposed to cranking currents. Joel ________________________________ Message 4 _____________________________________ Time: 07:33:50 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Noise --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 01:25 AM 2/4/2004 -0500, you wrote: >--> AeroElectric-List message posted by: "Scott Hersha" > >I haven't tried any experiments yet except using a ferrite toroid on the >antenna lead. No help. After reading chapter 16, I think I potentially have >several areas for concern. My wires are probably not bundled properly to >keep certain wires separated. Possible problem but pretty low on list of probabilities > My strobe power lead shield is grounded at the >power supply only not the strobe lamp also. that's fine. ground shield at power supply end only. > I'm going to build 3 >capacitor/filters you describe, one for the intercom power, and one each for >the two strobe power supplys. Whups . . . don't do this yet. > I'm also going to try connecting my com radio >to a 'clean' power source..separate battery. Good idea. > I'll disconnect the radio >antenna first to see if the noise is coming through it or the bus. another good idea > All these >'experiments' will take some time, but if none of these work, I'll get back >to you. Do the detective work before you buy any parts. We await the results of your investigation. Bob . . . ________________________________ Message 5 _____________________________________ Time: 07:42:41 AM PST US From: N27160@aol.com Subject: AeroElectric-List: Antenna(S) for Com(s)? --> AeroElectric-List message posted by: N27160@aol.com Im adding a second com to my airplane. question is, do I need a second com antenna if I dont intend to transmit on both coms at the same time? ________________________________ Message 6 _____________________________________ Time: 08:27:42 AM PST US From: Rick Johnson Subject: AeroElectric-List: start up/shut down procedure --> AeroElectric-List message posted by: Rick Johnson Bob: I am wiring my RV7 according to your Z-13 and Z-24 diagrams. The only exception is I am using a 2-3 switch for my battery/alternator field switch instead of your 2-10. I would like to know what the proper start up - system check - shut down procedure should be. How should I check to see if the SD-8 alternator is working correctly after the engine is running? What will the ammeter on that circuit read if the auxiliary alternator switch is off? Sounds like after start up, I wouldn't want to switch off the battery/primary alternator then switch on the e-bus and auxiliary alternator to see if it is carrying the system load properly. I'm confused and would rather get some good advice from you before ruining some expensive equipment. And thanks for your fantastic web site and all the great advice you dispense here. rick ________________________________ Message 7 _____________________________________ Time: 09:08:02 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Antenna(S) for Com(s)? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:42 AM 2/4/2004 -0500, you wrote: >--> AeroElectric-List message posted by: N27160@aol.com > >Im adding a second com to my airplane. question is, do I need a second com >antenna if I dont intend to transmit on both coms at the same time? Yes, you'll want to listen on both and while this could be done with a splitter, you can't used the splitter to transmit. If you use a relay or switch to put one antenna on the active transmitter, then you can't hear on both receivers. Further, putting such gizmos in the antenna for both transceivers gives you a single point of failure for both radios. You loose both utility and reliability when you try to share the antenna between two transceivers. Bob . . . ________________________________ Message 8 _____________________________________ Time: 09:13:20 AM PST US From: "Wayne Berg" Subject: Re: AeroElectric-List: Antenna(S) for Com(s)? --> AeroElectric-List message posted by: "Wayne Berg" Yes. You would need a coax switch in the line to isolate your transmitters. Without that or a second antenna you would be sending RF back into the second Com. Very bad and very expensive. Keep second com antenna at least 21" from the other com antenna. ----- Original Message ----- From: N27160@aol.com Subject: AeroElectric-List: Antenna(S) for Com(s)? --> AeroElectric-List message posted by: N27160@aol.com Im adding a second com to my airplane. question is, do I need a second com antenna if I dont intend to transmit on both coms at the same time? ________________________________ Message 9 _____________________________________ Time: 10:49:18 AM PST US From: Clay R Subject: Re: AeroElectric-List: Re: OV protection for internally regulated alternators --> AeroElectric-List message posted by: Clay R I'm going to reluctantly reply to your message and it will be my very last post to this list on the subject. I personally feel like I am being blamed for "not knowing" that I shouldn't have switched off the alternator switch while the engine was running. Sorry if I was taught it could be done on a Cessna... old habits die hard and turning off the alternator with the engine running shouldn't be OK on one plane but not another unless labeled as such. All I originally wanted was a warning on Z-24 to keep others from making the same mistake I did. --- "Robert L. Nuckolls, III" wrote: > --> AeroElectric-List message posted by: "Robert L. > Nuckolls, III" > > > Z-24 has been published for several years. I have > to believe there have been a lot of systems > installed > and are flying. The questions are: > Z-24 may have been published for several years... but that DOES NOT mean there are a lot of people flying it yet and there isn't a problem with it. The time required to build an airplane means that an idea needs to be out there for a year or two before it will be flying. When it was published, builders would need to be BEFORE the wiring stage to implement this idea easily... those that had already planned and started their wiring when z-24 was published probably didn't implement it because the idea was new and would require rework. I personally have never encountered another z-24 airplane flying, and neither had the DAR who certifies experimental planes every week in the Dallas area. Please, speak up if you have your flying plane wired like z-24 and have (or have not) seen any issues with it. Any additional data points will help. > (1) how many alternators are subject to this > failure > because their internal regulators are not rated > for > the battery-dump stress? > > (2) how many builders have put their particular > alternator "to the test" by cycling the > alternator > control switch while the alternator was working > hard? > I had my EFIS/One turned on (3.5A), the Lightspeed (1.3A), and the engine was at a slow idle. My battery was charged, and there were no radios on, no lights, nothing else... Does this qualify as working hard? > There are so many variables here that a truly > quantitative response to your question cannot be > deduced from what we know. > > I'm not sure which alternator Van's is selling. > I THOUGHT it was an ND alternator. Does anyone > know? My alternator from Vans has ND stamped on it. > > It does take a combination of conditions to > trigger the event: > > (1) relatively old design for built in regulator > that is NOT protected from the battery-dump > transient. > > (2) size of the transient is a function of how > fast alternator is running and at what load > when the connection between b-lead and battery > is broken. > > When fitted with rudimentary electrical system > instrumentation (low volts warning light or > a voltmeter) there is no practical need or > routinely exercised practice that calls for > opening the alternator disconnect contactor > while the engine is running IRRESPECTIVE > of alternator vulnerability. > > If EVERY airplane I've ever rented over the > past 23 years had been vulnerable to this > failure mode, I'm 99.9% certain that the mode > would not have been triggered while I was > using the airplane . . . i.e. I've never > had a situation arise where it was valuable > or even interesting to operate the switch > with the engine running. Rental airplanes and OBAM with z-24 are different... Rentals have externally regulated alternators without a contactor on the B-lead. > > At the moment, my sense is that given the way > MOST of us were taught (or not) on how > to operate the airplane, the risks to even > vulnerable alternators is quite low. > > The risk can be driven essentially zero once > the magnitude of the transient is characterized > and prophylactic measures implemented. At this > point in the investigation, it would be a sad > thing for a builder to jerk his perfectly working > alternator off in knee-jerk response to truthful > but poorly quantified warnings from well meaning > folks who don't understand the system. > > Bob . . . If I'm the one giving the truthful but poorly quantified warning, and don't understand the system, I'm sorry for being well-meaning and bringing it up. In retrospect, It would have been less stressful to quietly switch to an externally regulated alternator and left it for someone else to bring up. From the amount of email I've received, people seem to be happy I've shared my experience with the group. I do believe that once the problem is fully tested and understood a fix will be found for z-24 (or no problem will be found at all.. it was user error), and everyone will be happy once again. We live and learn and move on. For now Bob's right, don't change your alternator, just don't switch it off unless you want to help with the testing. ;-) -Clay __________________________________ ________________________________ Message 10 ____________________________________ Time: 11:10:35 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Internally regulated alternators --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:22 AM 2/4/2004 -0700, you wrote: >Here is a single point anecdotal observation. > >There is only one "Vans" 60 Amp alternator on our airfield, and it is a >rebuilt Mitsubishi. It looks like a later generation alternator ( Vented >frame, and internal fans); however it is of the ilk which, once activated >with the alt switch, it will not turn off with the alt switch. He has had >no serious problems with it. This one was purchased several years ago and >no telling what Van is selling now. This is consistent with other notes I'm getting. Van's has sold several different models over the years. None are new, most if not all are re-builds of some kind. Here's where it gets sticky. These modern alternators are mechanically and electrically quite robust. I'd guess that the most common reason for an alternator to be replaced is from brush wear, bearing wear or regulator failure. For every OEM that builds alternators as products they'll be proud of, there are dozens of after-market manufacturers of replacement regulators. I've often opined that ND alternators are among the best bets out there for a reliable alternator . . . this is reinforced with first hand knowledge of B&C's success with this product. B&C chooses not to put original equipment regulators to the test opting instead of offering their own flavor of external regulator. Once the alternator is opened for rebuilding, there is risk that the final product will become something less than the original manufacturer would be willing to put their brand on. The biggest single variable will be design of a replacement regulator. "Load dump" in cars is a very rare event . . . if a regulator manufacturer can make a few pennies more per unit by short changing load dump immunity . . . well, we know which way that decision often goes. >Most of the other Van's planes on our air field have Denso 40 A alternators >which came from Niagra Air Parts, and are new, fairly late models. These >look just like the B&C, but have internal regulators. I have personally >checked several times and it does shut down with the switch >(Sensor/regulator power?). I have it wired with the contactor and OVM. I >have also opened the Alt main (B lead) CB several times when under load and >it doesn't seem to harm it. I ain't doing that any more; however. I start >with it off and turn it on when the motor is running. It comes off after >engine shut down. A very rational approach to risk reduction . . . and it may be that you're seeing mostly new machines with ND original regulators that are not vulnerable to battery-dump events. >It is therefore my belief that the very popular 40 Amp Denso bought new from >Niagra has a regulator which has dump logic in it. It seems bullet proof in >that regard; however I still feel the need for the OV module and contactor, >in case of the internal failure mode which you describe. > >This is not much of a data point but it sounds like you are starting from >scratch, so I hope this helps. Very helpful, thanks! Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________ Message 11 ____________________________________ Time: 11:12:29 AM PST US From: N67BT@aol.com Subject: AeroElectric-List: Connector for elevator trim servo --> AeroElectric-List message posted by: N67BT@aol.com Photos and info on the Hirose connector I plan to use for the elevator trim servo are posted on my web site. http://users.aol.com/n67bt This thing looks like just the ticket. What do you think Bob N.? They cost around $14 for the pair. Bob Trumpfheller RV7A Western Colorado ________________________________ Message 12 ____________________________________ Time: 11:13:54 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: start up/shut down procedure --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:55 AM 2/4/2004 -0700, you wrote: >--> AeroElectric-List message posted by: Rick Johnson > >Bob: I am wiring my RV7 according to your Z-13 and Z-24 diagrams. The >only exception is I am using a 2-3 switch for my battery/alternator field >switch instead of your 2-10. I would like to know what the proper start up >- system check - shut down procedure should be. How should I check to see >if the SD-8 alternator is working correctly after the engine is running? >What will the ammeter on that circuit read if the auxiliary alternator >switch is off? Sounds like after start up, I wouldn't want to switch off >the battery/primary alternator then switch on the e-bus and auxiliary >alternator to see if it is carrying the system load properly. I'm confused >and would rather get some good advice from you before ruining some >expensive equipment. And thanks for your fantastic web site and all the >great advice you dispense here. I'll suggest that you replace the 2-3 with a 2-10. Start with battery only. After engine starts, test the SD-8 before you turn the main alternator on. An option: Make the aux alternator switch a 2-3 where control current for main alternator goes through the second set of contacts such that the main alternator is disabled any time the SD-8 is ON. Start with the both DC PWR MASTER and AUX ALT switches ON. After preflight of the SD-8 is complete, turn it OFF and it will be replaced by the main alternator. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________ Message 13 ____________________________________ Time: 11:40:02 AM PST US From: "Ned Thomas" <315@cox.net> Subject: Re: AeroElectric-List: start up/shut down procedure --> AeroElectric-List message posted by: "Ned Thomas" <315@cox.net> Don't know if this is pertainant to this thread but I understand that once the SD-8 is energized it remains energized producing power until it stops rotating. It hasn't been made clear to me whether this is detrimental to have it running energized while disconnected from everything?? ________________________________ Message 14 ____________________________________ Time: 11:56:40 AM PST US From: "Steve Sampson" Subject: RE: AeroElectric-List: Re: OV protection for internally regulated alternators / ND alternator --> AeroElectric-List message posted by: "Steve Sampson" Michael/Bob, The alternator VANS shipped to me IS a refurb Nippon Denso (Spelling?) alternator. It is the one on p7 of the 2003 accesory catalogue. I had suggested the 35Amp externally regulated one but they suggested this was a better bet and lighter. Steve. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Robert L. Nuckolls, III Subject: AeroElectric-List: Re: OV protection for internally regulated alternators --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:15 PM 2/3/2004 -0800, you wrote: >--> AeroElectric-List message posted by: Michel Therrien > >That battery dump damage thing... is this only related >with the alternators from Vans, or any automotive >alternators (including the Nippodensos found in >japanese cars)? > >Is this a certainty that it will fail each time, or is >it once in a lifetime that this will happen? > >Thanks! > >Michel Z-24 has been published for several years. I have to believe there have been a lot of systems installed and are flying. The questions are: (1) how many alternators are subject to this failure because their internal regulators are not rated for the battery-dump stress? (2) how many builders have put their particular alternator "to the test" by cycling the alternator control switch while the alternator was working hard? There are so many variables here that a truly quantitative response to your question cannot be deduced from what we know. I'm not sure which alternator Van's is selling. I THOUGHT it was an ND alternator. Does anyone know? It does take a combination of conditions to trigger the event: (1) relatively old design for built in regulator that is NOT protected from the battery-dump transient. (2) size of the transient is a function of how fast alternator is running and at what load when the connection between b-lead and battery is broken. When fitted with rudimentary electrical system instrumentation (low volts warning light or a voltmeter) there is no practical need or routinely exercised practice that calls for opening the alternator disconnect contactor while the engine is running IRRESPECTIVE of alternator vulnerability. If EVERY airplane I've ever rented over the past 23 years had been vulnerable to this failure mode, I'm 99.9% certain that the mode would not have been triggered while I was using the airplane . . . i.e. I've never had a situation arise where it was valuable or even interesting to operate the switch with the engine running. At the moment, my sense is that given the way MOST of us were taught (or not) on how to operate the airplane, the risks to even vulnerable alternators is quite low. The risk can be driven essentially zero once the magnitude of the transient is characterized and prophylactic measures implemented. At this point in the investigation, it would be a sad thing for a builder to jerk his perfectly working alternator off in knee-jerk response to truthful but poorly quantified warnings from well meaning folks who don't understand the system. Bob . . . --- Incoming mail is certified Virus Free. --- ________________________________ Message 15 ____________________________________ Time: 12:02:46 PM PST US From: Dave Morris Subject: Re: AeroElectric-List: Antenna(S) for Com(s)? --> AeroElectric-List message posted by: Dave Morris You could build up a relay that your PTT connector plugs into, that would disconnect the 2nd comm radio from the antenna when you push the mike button. A lot has been written about that sort of thing in the amateur radio circles. If you're handy with a soldering iron, do a Google.com search for QSK TR SWITCH and see what's been written. Dave Morris N5UP At 11:07 AM 2/4/2004 -0600, you wrote: >--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > >At 10:42 AM 2/4/2004 -0500, you wrote: > >--> AeroElectric-List message posted by: N27160@aol.com > > > >Im adding a second com to my airplane. question is, do I need a second com > >antenna if I dont intend to transmit on both coms at the same time? > > Yes, you'll want to listen on both and while this could be done > with a splitter, you can't used the splitter to transmit. If you > use a relay or switch to put one antenna on the active transmitter, > then you can't hear on both receivers. > > Further, putting such gizmos in the antenna for both transceivers > gives you a single point of failure for both radios. You loose > both utility and reliability when you try to share the antenna > between two transceivers. > > Bob . . . > > Dave Morris ________________________________ Message 16 ____________________________________ Time: 12:07:03 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: OV protection for internally regulated alternators --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:48 AM 2/4/2004 -0800, you wrote: >--> AeroElectric-List message posted by: Clay R > >I'm going to reluctantly reply to your message and it >will be my very last post to this list on the subject. > >I personally feel like I am being blamed for "not >knowing" that I shouldn't have switched off the >alternator switch while the engine was running. Not at all my friend. There was nothing inherently wrong with turning the alternator on/off at ANY time . . . under the best of circumstances it shouldn't be a problem with ANY alternator on ANY airplane whether certified or OBAM. >Sorry if I was taught it could be done on a Cessna... >old habits die hard and turning off the alternator >with the engine running shouldn't be OK on one plane >but not another unless labeled as such. All I >originally wanted was a warning on Z-24 to keep others >from making the same mistake I did. Exactly. My comments were directed not at you for doing what you were taught but more toward your teachers who were augmenting the POH by suggesting a pre-flight activity that added no value . . . which serendipitously exposed a vulnerability of an alternator in an OBAM aircraft. This happens all the time in both the certified and OBAM world. Some day when I don't have to worry about ticking off the folks who sign my paychecks, I'll be able to relate some pretty hair-raising anecdotes in the heavily regulated and conformed world of certified aircraft. If my tone was skeptical/sarcastic/incredulous please know it had nothing to do with you personally. We're all products of our experiences. I'm singularly fortunate to have a rich history of experiences. My job is not to convince you of anything but to share what I've learned and try to explain how the simple-ideas piece together to make a system work/not-work. You're encouraged to use any part of this effort in which you find value. If you find something I've offered unconvincing, it's either because I'm in error or I've failed in my role as teacher. I am pleased that you DID reply and make me aware of your perceptions. It probably happens to others who feel like they're being chased off. I encourage you and others who participate on this list to remember that when the wild-eyed, gray beard in the Spam Can Capitol gets all excited, it's about the physics and logic of the matter, not the folks . . . and in particular folks who are helping me help others by sharing their own experiences. Please don't let this experience become inhibiting. There's a lot of sand and dust to sift to search out the simple-ideas. I value and appreciate your participation more than you know. When the dust finally settles on any discussion, it's my most sincere wish that we will have sorted out the best ideas worthy of passing on to others. Bob . . . ________________________________ Message 17 ____________________________________ Time: 12:07:43 PM PST US From: "Steve Sampson" Subject: RE: AeroElectric-List: Re: OV protection for internally regulated alternators --> AeroElectric-List message posted by: "Steve Sampson" Clay - thanks VERY much for raising this issue. It has been very helpful to me. Dont feel bad. Steve. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Clay R Subject: Re: AeroElectric-List: Re: OV protection for internally regulated alternators --> AeroElectric-List message posted by: Clay R I'm going to reluctantly reply to your message and it will be my very last post to this list on the subject. I personally feel like I am being blamed for "not knowing" that I shouldn't have switched off the alternator switch while the engine was running. Sorry if I was taught it could be done on a Cessna... old habits die hard and turning off the alternator with the engine running shouldn't be OK on one plane but not another unless labeled as such. All I originally wanted was a warning on Z-24 to keep others from making the same mistake I did. --- "Robert L. Nuckolls, III" wrote: > --> AeroElectric-List message posted by: "Robert L. > Nuckolls, III" > > > Z-24 has been published for several years. I have > to believe there have been a lot of systems > installed > and are flying. The questions are: > Z-24 may have been published for several years... but that DOES NOT mean there are a lot of people flying it yet and there isn't a problem with it. The time required to build an airplane means that an idea needs to be out there for a year or two before it will be flying. When it was published, builders would need to be BEFORE the wiring stage to implement this idea easily... those that had already planned and started their wiring when z-24 was published probably didn't implement it because the idea was new and would require rework. I personally have never encountered another z-24 airplane flying, and neither had the DAR who certifies experimental planes every week in the Dallas area. Please, speak up if you have your flying plane wired like z-24 and have (or have not) seen any issues with it. Any additional data points will help. > (1) how many alternators are subject to this > failure > because their internal regulators are not rated > for > the battery-dump stress? > > (2) how many builders have put their particular > alternator "to the test" by cycling the > alternator > control switch while the alternator was working > hard? > I had my EFIS/One turned on (3.5A), the Lightspeed (1.3A), and the engine was at a slow idle. My battery was charged, and there were no radios on, no lights, nothing else... Does this qualify as working hard? > There are so many variables here that a truly > quantitative response to your question cannot be > deduced from what we know. > > I'm not sure which alternator Van's is selling. > I THOUGHT it was an ND alternator. Does anyone > know? My alternator from Vans has ND stamped on it. > > It does take a combination of conditions to > trigger the event: > > (1) relatively old design for built in regulator > that is NOT protected from the battery-dump > transient. > > (2) size of the transient is a function of how > fast alternator is running and at what load > when the connection between b-lead and battery > is broken. > > When fitted with rudimentary electrical system > instrumentation (low volts warning light or > a voltmeter) there is no practical need or > routinely exercised practice that calls for > opening the alternator disconnect contactor > while the engine is running IRRESPECTIVE > of alternator vulnerability. > > If EVERY airplane I've ever rented over the > past 23 years had been vulnerable to this > failure mode, I'm 99.9% certain that the mode > would not have been triggered while I was > using the airplane . . . i.e. I've never > had a situation arise where it was valuable > or even interesting to operate the switch > with the engine running. Rental airplanes and OBAM with z-24 are different... Rentals have externally regulated alternators without a contactor on the B-lead. > > At the moment, my sense is that given the way > MOST of us were taught (or not) on how > to operate the airplane, the risks to even > vulnerable alternators is quite low. > > The risk can be driven essentially zero once > the magnitude of the transient is characterized > and prophylactic measures implemented. At this > point in the investigation, it would be a sad > thing for a builder to jerk his perfectly working > alternator off in knee-jerk response to truthful > but poorly quantified warnings from well meaning > folks who don't understand the system. > > Bob . . . If I'm the one giving the truthful but poorly quantified warning, and don't understand the system, I'm sorry for being well-meaning and bringing it up. In retrospect, It would have been less stressful to quietly switch to an externally regulated alternator and left it for someone else to bring up. From the amount of email I've received, people seem to be happy I've shared my experience with the group. I do believe that once the problem is fully tested and understood a fix will be found for z-24 (or no problem will be found at all.. it was user error), and everyone will be happy once again. We live and learn and move on. For now Bob's right, don't change your alternator, just don't switch it off unless you want to help with the testing. ;-) -Clay __________________________________ --- Incoming mail is certified Virus Free. --- ________________________________ Message 18 ____________________________________ Time: 12:11:36 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: start up/shut down procedure --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 01:41 PM 2/4/2004 -0600, you wrote: >--> AeroElectric-List message posted by: "Ned Thomas" <315@cox.net> > >Don't know if this is pertainant to this thread but I understand that once >the SD-8 is energized it remains energized producing power until it stops >rotating. > >It hasn't been made clear to me whether this is detrimental to have it >running energized while disconnected from everything?? No, the SD-8 is a permanent magnet alternator. It's ALWAYS producing output power whether or not it is turned on or loaded. At this time I'm unaware of any risk to the alternator system for operating it in the unloaded mode. There are airplanes flying the All-Electric-Airplane- on-a-Budget system with hundreds of trouble free hours on them. I had one builder write a year or more ago to tell me that the SD-8 in his airplane had been called upon to do its job after a wire became unhooked in his main alternator system. He said the system performed as expected. Bob . . . ________________________________ Message 19 ____________________________________ Time: 12:25:47 PM PST US Subject: Re: AeroElectric-List: start up/shut down procedure From: "Matt Prather" --> AeroElectric-List message posted by: "Matt Prather" Hi Bob, You said that the damaging voltage dump conditions happens when the alternator is under significant load, and is suddenly disconnected from that load. I gather that the problem is that some of the regulators don't pull down the field current fast enough to reduce the output of the alternator. Is that right? Or is that there is signficant inductive stored energy in the output of the alternator, and driving the output current to zero by disconnecting the alternator causese the output voltage to spike? Either way, would you say that the alternator can safely be disconnected when its output current is low (0A)? Have to wait until the battery is charged, and the pitot heat/nav lights are off... I also wonder how large the disconnect relay needs to be if attempting to disconnect the alternator from the bus causes such a large transient. Will the small relays that you sell be up to the task for an airplane that doesn't have a starter (ie, no large contactor)? One final question: What effect will the TVS have should the atl/reg suffer from an over voltage event, not related to turning off the alt switch while the engine is running? Will the TVS have a turn-on voltage higher than a typical overvoltage value? I suppose this may be a moot point, since if the regulator cooks, causing an ov even, I may not care what happens to the TVS, as long as the crow bar stuff works. None of these questions is of earth shattering significance, as it appears that you fully understand what is going on. However, I am interested in the topic out of curiousity. I am interested in seeing any data you take with regard to how long the battery/load dump even lasts, and how much total engergy is dissipated in the process. Regards, Matt Prather N34RD ________________________________ Message 20 ____________________________________ Time: 01:25:01 PM PST US From: Kent Sorensen Subject: AeroElectric-List: OBAM ? --> AeroElectric-List message posted by: Kent Sorensen I keep seeing the acronym OBAM. It 's obviously referring to amateur built aircraft as opposed to certified ones. What does it stand for ? Owner Built Amateur Made or something ? Kent ________________________________ Message 21 ____________________________________ Time: 01:27:25 PM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: OBAM ? --> AeroElectric-List message posted by: BobsV35B@aol.com In a message dated 2/4/04 3:26:07 PM Central Standard Time, kents@snak.com writes: Owner Built Amateur Made or something ? Owner Built And Maintained Do Not Archive Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Airpark LL22 Downers Grove, IL 60516 630 985-8502 ________________________________ Message 22 ____________________________________ Time: 01:32:43 PM PST US From: Dj Merrill Subject: Re: AeroElectric-List: Re: OV protection for internally regulated alternators --> AeroElectric-List message posted by: Dj Merrill Steve Sampson wrote: > --> AeroElectric-List message posted by: "Steve Sampson" > > Clay - thanks VERY much for raising this issue. It has been very helpful to > me. Dont feel bad. Steve. And educational for me. It is good to question things less we become too complacent... ;-) Please continue to do so. Unless questioned, we generally take things our flight instructors teach us as gospel. Flight instructors are people, too, and might make mistakes or assumptions about things that aren't entirely true. This is a great forum for flushing out those myths about electrical related items in aircraft. I usually lurk, rather than post, and I've learned tons! :-) -Dj -- Dj Merrill Thayer School of Engineering ThUG Sr. Unix Systems Administrator 8000 Cummings Hall deej@thayer.dartmouth.edu - N1JOV Dartmouth College, Hanover, NH 03755 "On the side of the software box, in the 'System Requirements' section, it said 'Requires Windows 95 or better'. So I installed Linux." -Anonymous ________________________________ Message 23 ____________________________________ Time: 01:40:48 PM PST US From: "Ned Thomas" <315@cox.net> Subject: AeroElectric-List: Alternator Recommendation and Conversions --> AeroElectric-List message posted by: "Ned Thomas" <315@cox.net> I thought I would recount my experience with Powermaster for those of you looking for an alternator. I would also suggest B&C. Powermaster is an automotive aftermarket firm specializing in racing products. You can buy them thru Summit and others and sometimes on eBay. http://store.summitracing.com/partdetail.asp?part=PWM%2D8162 After I experienced the OV on the RV6A, I took the alternator in to the local O'Reilly's and they put it on the test stand. It immediately produced 25 volts. I called the vendor, powermaster, and explained the situation. They said send it back and we'll repair it. They repaired it for free and ran it thru their tests and sent me their results tabulated and graphed. This alternator is a version of the Denso and was a "one wire" alternator. Powermaster told me they could configure it so that an additional wire would be available to turn on / off the alternator. So when I incorporated the Z-24 suggestions to the rewiring it worked fine. I had no problem with this alternator wired with the OV protection as suggested by Z-24. It was a 50 amp model 8162 and was very light at 5.68-lbs. It has what they call a "heat dispersant coating" that is black. http://www.powermastermotorsports.com/Racing/Denso_Alternators/denso_alternators.html More details: http://www.powermastermotorsports.com/Tech_Help/FAQ_s_-_Racing_Alternators/faq_s_-_racing_alternators.html#race3 For those interested the test data was: Max output power: 695 Watts Max output power under full load 53 Amps Field current 0.01 Amps Turn on Speed (less than): 2600RPM Leakage current tested @ 12 volts: 0.75 Amps Ripple current @ 2500 RPM: 11 Amps Pulley ratio: 2.05 There is a graph of Amps vs RPM and a Scope pattern at 2500 RPM that looks like a sine wavefrom +- about 7Amps I don't know what much of this means but it was nice to have the data...... Although the B&C weighs slightly more at 6.1 lbs it might be a better option. http://www.bandcspecialty.com/L40desc.html http://www.bandcspecialty.com/L40-out.PDF To convert and internally regulated alternator to and external regulated alternator I found the following link quite helpful: http://www.miramarcollege.net/programs/avim/faculty/north/alternator/index.htm Best Regards, Ned ________________________________ Message 24 ____________________________________ Time: 01:46:33 PM PST US From: "Ageless Wings" Subject: RE: AeroElectric-List: OBAM ? --> AeroElectric-List message posted by: "Ageless Wings" Hi, Kent... I'll save Bob the effort this time! You are close....it's Owner Built and Maintained. Harley Long EZ N28EZ... in the hanger, getting sanded and primed! Harley Dixon Website: www.AgelessWings.com Email: harley@agelesswings.com Henrietta, NY USA |-----Original Message----- |From: owner-aeroelectric-list-server@matronics.com |[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Kent |Sorensen |Sent: Wednesday, February 04, 2004 4:24 PM |To: aeroelectric-list@matronics.com |Subject: AeroElectric-List: OBAM ? | | |--> AeroElectric-List message posted by: Kent Sorensen | |I keep seeing the acronym OBAM. It 's obviously referring to amateur |built aircraft as opposed to certified ones. What does it stand for ? | |Owner Built Amateur Made or something ? | |Kent | | | | | | | ________________________________ Message 25 ____________________________________ Time: 02:09:09 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: OV protection for internally regulated alternators --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:57 PM 2/4/2004 +0000, you wrote: >--> AeroElectric-List message posted by: "Steve Sampson" > > >Michael/Bob, The alternator VANS shipped to me IS a refurb Nippon Denso >(Spelling?) alternator. It is the one on p7 of the 2003 accesory catalogue. >I had suggested the 35Amp externally regulated one but they suggested this >was a better bet and lighter. > >Steve. Thanks Steve. It may be that "refurb" regulators are the real root cause of the vulnerability. Bob . . . ________________________________ Message 26 ____________________________________ Time: 02:21:47 PM PST US From: "Beckman, Rick" ernators Subject: RE: AeroElectric-List: OV protection for internally regulated alt ernators --> AeroElectric-List message posted by: "Beckman, Rick" >I personally feel like I am being blamed ....... Please don't let this experience become inhibiting. There's a lot of sand and dust to sift to search out the simple-ideas. I value and appreciate your participation more than you know. When the dust finally settles on any discussion, it's my most sincere wish that we will have sorted out the best ideas worthy of passing on to others. Bob . . . Bob,.... Thanks for that excellent reply, further assuring your public that no matter what the discussion, it never becomes a personal grudge match with you and others involved. I, personally, have gleaned a wealth of information from all the Matronics sites to which I subscribe, definitely this one! Keep on keepin' on! See ya Saturday! God Bless! Rick ________________________________ Message 27 ____________________________________ Time: 02:23:24 PM PST US From: "Dan Branstrom" Subject: Re: AeroElectric-List: OBAM ? --> AeroElectric-List message posted by: "Dan Branstrom" Owner Built And Maintained. I asked the same question a while ago. ; ) Dan Branstrom ----- Original Message ----- From: "Kent Sorensen" Subject: AeroElectric-List: OBAM ? > --> AeroElectric-List message posted by: Kent Sorensen > > I keep seeing the acronym OBAM. It 's obviously referring to amateur > built aircraft as opposed to certified ones. What does it stand for ? > > Owner Built Amateur Made or something ? > > Kent > > ________________________________ Message 28 ____________________________________ Time: 02:24:22 PM PST US From: "Jon Finley" Subject: RE: AeroElectric-List: OBAM ? --> AeroElectric-List message posted by: "Jon Finley" Owner Built And Maintained. It has confused many of us. I love it though. I've used it many times lately and it is always received much better than Experimental and Homebuilt by the "non-flying folk." Jon DO NOT ARCHIVE -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Kent Sorensen Subject: AeroElectric-List: OBAM ? --> AeroElectric-List message posted by: Kent Sorensen I keep seeing the acronym OBAM. It 's obviously referring to amateur built aircraft as opposed to certified ones. What does it stand for ? Owner Built Amateur Made or something ? Kent ________________________________ Message 29 ____________________________________ Time: 02:41:12 PM PST US From: "Bartrim, Todd" ernators Subject: RE: AeroElectric-List: OV protection for internally regulated alt ernators --> AeroElectric-List message posted by: "Bartrim, Todd" > Some day when I don't have to > worry about ticking off the folks who sign my > paychecks, I'll be able to relate some pretty > hair-raising anecdotes in the heavily regulated > and conformed world of certified aircraft. > Now, I'd buy that book. :-) Do Not Archive S. Todd Bartrim Turbo 13B RX-9endurance C-FSTB http://www3.telus.net/haywire/RV-9/C-FSTB.htm "Imagination is more important than knowledge" -Albert Einstein RE: AeroElectric-List: OV protection for internally regulated alternators Some day when I don't have to worry about ticking off the folks who sign my paychecks, I'll be able to relate some pretty hair-raising anecdotes in the heavily regulated and conformed world of certified aircraft. Now, I'd buy that book. :-) Do Not Archive S. Todd Bartrim Turbo 13B RX-9endurance C-FSTB http://www3.telus.net/haywire/RV-9/C-FSTB.htm Imagination is more important than knowledge -Albert Einstein ________________________________ Message 30 ____________________________________ Time: 03:02:56 PM PST US From: Dave Morris Subject: Re: AeroElectric-List: OBAM ? --> AeroElectric-List message posted by: Dave Morris At 04:24 PM 2/4/2004 -0500, you wrote: >--> AeroElectric-List message posted by: Kent Sorensen > >I keep seeing the acronym OBAM. It 's obviously referring to amateur >built aircraft as opposed to certified ones. What does it stand for ? It's the sound made by an airplane builder when he discovers tab A does not fit in slot B. Dave Morris ________________________________ Message 31 ____________________________________ Time: 03:37:32 PM PST US From: Joe Dubner Subject: AeroElectric-List: Re: OV protection for internally regulated alternators --> AeroElectric-List message posted by: Joe Dubner On 04-Feb-04 11:48 Clay R wrote: > I personally feel like I am being blamed for "not > knowing" that I shouldn't have switched off the > alternator switch while the engine was running. [... deleted ..] > Please, speak up if you have your flying plane wired > like z-24 and have (or have not) seen any issues with > it. Any additional data points will help. Clay, if there's blame to be assigned (lets hope there isn't), I'll take some too. My Long-EZ is wired like Z-24 and I've turned off my alternator in flight many times and under vaying load conditions. My reasons may not pass muster but what the heck, it's my airplane. Some of these reasons are: 1) testing the operation of the alternator contactor I added; I was horrified to discover that my purchased Long-EZ had no way to disable the alternator in case of an electrical fire. 2) Troubleshooting a noisy Aerospace Logic EGT indicator; it worked OK on battery but noise from the alternator caused readings to vary. 3) Simulating alternator failure in flight; I wanted to see what it was like to fly battery only to my destination before it actually happened. No big deal. FWIW, my alternator has no identifying marks other than a "Hitachi" label. Perhaps I've just been lucky but I didn't know this was an issue either. Thank you for bringing this up and sharing your experience with the group. -- Joe Long-EZ 821RP Gilbert, AZ ________________________________ Message 32 ____________________________________ Time: 04:11:52 PM PST US From: "AI Nut" Subject: Re: AeroElectric-List: start up/shut down procedure --> AeroElectric-List message posted by: "AI Nut" Web site? ----- Original Message ----- From: "Rick Johnson" Subject: AeroElectric-List: start up/shut down procedure > --> AeroElectric-List message posted by: Rick Johnson > > Bob: I am wiring my RV7 according to your Z-13 and Z-24 diagrams. The > only exception is I am using a 2-3 switch for my battery/alternator field > switch instead of your 2-10. I would like to know what the proper start up > - system check - shut down procedure should be. How should I check to see > if the SD-8 alternator is working correctly after the engine is running? > What will the ammeter on that circuit read if the auxiliary alternator > switch is off? Sounds like after start up, I wouldn't want to switch off > the battery/primary alternator then switch on the e-bus and auxiliary > alternator to see if it is carrying the system load properly. I'm confused > and would rather get some good advice from you before ruining some > expensive equipment. And thanks for your fantastic web site and all the > great advice you dispense here. > > rick > > ________________________________ Message 33 ____________________________________ Time: 04:11:55 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: OV protection for internally regulated alternators --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 04:36 PM 2/4/2004 -0700, you wrote: >--> AeroElectric-List message posted by: Joe Dubner > >On 04-Feb-04 11:48 Clay R wrote: > > > I personally feel like I am being blamed for "not > > knowing" that I shouldn't have switched off the > > alternator switch while the engine was running. > >[... deleted ..] > > > Please, speak up if you have your flying plane wired > > like z-24 and have (or have not) seen any issues with > > it. Any additional data points will help. > >Clay, if there's blame to be assigned (lets hope there isn't), I'll take >some too. My Long-EZ is wired like Z-24 and I've turned off my >alternator in flight many times and under vaying load conditions. . . . if your alternator is a junk-yard take-off, it's quite likely to have the factory original voltage regulator in it. It's hard to tell without a teardown under experienced eyeballs. >My reasons may not pass muster but what the heck, it's my airplane. >Some of these reasons are: 1) testing the operation of the alternator >contactor I added; I was horrified to discover that my purchased Long-EZ >had no way to disable the alternator in case of an electrical fire. 2) >Troubleshooting a noisy Aerospace Logic EGT indicator; it worked OK on >battery but noise from the alternator caused readings to vary. 3) >Simulating alternator failure in flight; I wanted to see what it was >like to fly battery only to my destination before it actually happened. > No big deal. . . . and it shouldn't be. >FWIW, my alternator has no identifying marks other than a "Hitachi" >label. Perhaps I've just been lucky but I didn't know this was an issue >either. > >Thank you for bringing this up and sharing your experience with the group. Thanks for your input Joe. Bob . . . ________________________________ Message 34 ____________________________________ Time: 04:25:57 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: OBAM ? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 05:02 PM 2/4/2004 -0600, you wrote: >--> AeroElectric-List message posted by: Dave Morris > >At 04:24 PM 2/4/2004 -0500, you wrote: > > >--> AeroElectric-List message posted by: Kent Sorensen > > > >I keep seeing the acronym OBAM. It 's obviously referring to amateur > >built aircraft as opposed to certified ones. What does it stand for ? > >It's the sound made by an airplane builder when he discovers tab A does not >fit in slot B. Good one Dave! I'll have to remember that. I'm working on a white paper for the small aircraft directorate dealing with ageing aircraft issues. We'll start with alternators and batteries. I'm trying to drive home the point that aside from mechanical issues where things break loose and jam other things, neither of these items is by itself critical to flight. I've introduced the term OBAM to the FAA in this paper. Never can tell, it might germinate and take hold. The NEXT step is "CBOM" . . . commercially built, owner maintained. My dream machine is a Piper Pacer or Tri-Pacer with NICE front seats, a hell-of-a-cargo pad where the back seats used to be and a Z-13 electrical system. I think I could have a really nice mogas, x-country machine for well under $40K with a whole lot less build-time than starting from scratch. Bob . . . ________________________________ Message 35 ____________________________________ Time: 04:58:57 PM PST US From: Jim Oke alternators / ND alternator Subject: Re: AeroElectric-List: Re: OV protection for internally regulated alternators / ND alternator --> AeroElectric-List message posted by: Jim Oke alternators / ND alternator After following the Vans Nippon Denso saga for a day or so, I wonder if anyone can comment on the smaller Denso alternator that AeroSport Power supplies with their engines as an option. The one I received has a Nippon Denso tag as P/N 18504-6220 although it seems to be manufactured by Ishikawajima as P/N 100211-1680 and marketed by Denso. It has a B+ supply and can be run on a "single wire" control basis although there is a warning light connection as well. The unit has worked well in my limited flying to date (RV-6A). I am using a homebrew OVM with a B field contactor. And, no, I haven't experimented with a "battery dump" failure mode experiment as yet. Jim Oke RV-6A RV-3 Wpg, MB ----- Original Message ----- From: "Steve Sampson" Subject: RE: AeroElectric-List: Re: OV protection for internally regulated alternators / ND alternator > --> AeroElectric-List message posted by: "Steve Sampson" > > Michael/Bob, The alternator VANS shipped to me IS a refurb Nippon Denso > (Spelling?) alternator. It is the one on p7 of the 2003 accesory catalogue. > I had suggested the 35Amp externally regulated one but they suggested this > was a better bet and lighter. > > Steve. > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Robert > L. Nuckolls, III > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: Re: OV protection for internally regulated > alternators > > > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > At 07:15 PM 2/3/2004 -0800, you wrote: > >--> AeroElectric-List message posted by: Michel Therrien > > > >That battery dump damage thing... is this only related > >with the alternators from Vans, or any automotive > >alternators (including the Nippodensos found in > >japanese cars)? > > > >Is this a certainty that it will fail each time, or is > >it once in a lifetime that this will happen? > > > >Thanks! > > > >Michel > > Z-24 has been published for several years. I have > to believe there have been a lot of systems installed > and are flying. The questions are: > > (1) how many alternators are subject to this failure > because their internal regulators are not rated for > the battery-dump stress? > > (2) how many builders have put their particular > alternator "to the test" by cycling the alternator > control switch while the alternator was working > hard? > > There are so many variables here that a truly > quantitative response to your question cannot be > deduced from what we know. > > I'm not sure which alternator Van's is selling. > I THOUGHT it was an ND alternator. Does anyone > know? > > It does take a combination of conditions to > trigger the event: > > (1) relatively old design for built in regulator > that is NOT protected from the battery-dump > transient. > > (2) size of the transient is a function of how > fast alternator is running and at what load > when the connection between b-lead and battery > is broken. > > When fitted with rudimentary electrical system > instrumentation (low volts warning light or > a voltmeter) there is no practical need or > routinely exercised practice that calls for > opening the alternator disconnect contactor > while the engine is running IRRESPECTIVE > of alternator vulnerability. > > If EVERY airplane I've ever rented over the > past 23 years had been vulnerable to this > failure mode, I'm 99.9% certain that the mode > would not have been triggered while I was > using the airplane . . . i.e. I've never > had a situation arise where it was valuable > or even interesting to operate the switch > with the engine running. > > At the moment, my sense is that given the way > MOST of us were taught (or not) on how > to operate the airplane, the risks to even > vulnerable alternators is quite low. > > The risk can be driven essentially zero once > the magnitude of the transient is characterized > and prophylactic measures implemented. At this > point in the investigation, it would be a sad > thing for a builder to jerk his perfectly working > alternator off in knee-jerk response to truthful > but poorly quantified warnings from well meaning > folks who don't understand the system. > > Bob . . . > > > --- > Incoming mail is certified Virus Free. > > --- > > ________________________________ Message 36 ____________________________________ Time: 05:16:48 PM PST US From: "LarryRobertHelming" Subject: AeroElectric-List: BNC bulkhead pass-through connectors --> AeroElectric-List message posted by: "LarryRobertHelming" In this reference, http://www.mpja.com/listitems.asp?dept=93&main=83 under the sub heading of GENDER CHANGER BNC CONNECTOR are two items that I do not understand and would like some help with what ISOLATED and NOT Isolated means with respect to BNC connectors. Larry ________________________________ Message 37 ____________________________________ Time: 06:00:18 PM PST US From: Dave Morris Subject: Re: AeroElectric-List: BNC bulkhead pass-through connectors --> AeroElectric-List message posted by: Dave Morris I'm relatively sure it describes whether or not the outer conductor (where the shield connects) is isolated from the panel mounting hardware or not. Dave Morris At 06:16 PM 2/4/2004, you wrote: >--> AeroElectric-List message posted by: "LarryRobertHelming" > > >In this reference, http://www.mpja.com/listitems.asp?dept=93&main=83 under >the sub heading of GENDER CHANGER BNC CONNECTOR are two items that I do not >understand and would like some help with what ISOLATED and NOT Isolated >means with respect to BNC connectors. > >Larry > > ________________________________ Message 38 ____________________________________ Time: 06:10:50 PM PST US From: Charlie Kuss Subject: Re: AeroElectric-List: Converting a Denso Alternator #2 --> AeroElectric-List message posted by: Charlie Kuss At 10:51 PM 2/3/2004, you wrote: >--> AeroElectric-List message posted by: Hi There > > >I have a couple of Denso Alternators that I want to convert to nonregulated alternators. I've seen a few different sites that discribe how to do this, but not one that has the same type of regulator that are on my alternators. Both alternators I have have a plastic regulator/plug housing. There are cooling The regulator bolts to the diodes and brushes. I'm sure someone has done one of these alternators, I was at the junk yard today and many of the import cars used an alternator of this disign. I have some photos if that helps. > > >Thanks for any help. > > >Cameron ________________________________ Message 39 ____________________________________ Time: 06:27:40 PM PST US From: Charlie Kuss Subject: Re: AeroElectric-List: Converting a Denso Alternator #3 --> AeroElectric-List message posted by: Charlie Kuss Cameron, As you will read in the article, the author shows how to convert both the Nippon Denso models and the Mitsubishi units as well. Charlie >--> AeroElectric-List message posted by: Hi There > > >I have a couple of Denso Alternators that I want to convert to nonregulated alternators. I've seen a few different sites that discribe how to do this, but not one that has the same type of regulator that are on my alternators. Both alternators I have have a plastic regulator/plug housing. There are cooling The regulator bolts to the diodes and brushes. I'm sure someone has done one of these alternators, I was at the junk yard today and many of the import cars used an alternator of this disign. I have some photos if that helps. > > >Thanks for any help. > > >Cameron ________________________________ Message 40 ____________________________________ Time: 06:59:33 PM PST US From: Charlie Kuss Subject: Re: AeroElectric-List: Converting a Denso Alternator #3 --> AeroElectric-List message posted by: Charlie Kuss Sorry folks, These last 2 posts were intended for Cameron off list. I've had a long hard day. I'm now "officially" brain dead! :-( Charlie Kuss >--> AeroElectric-List message posted by: Charlie Kuss > >Cameron, > As you will read in the article, the author shows how to convert both the Nippon Denso models and the Mitsubishi units as well. >Charlie > >>--> AeroElectric-List message posted by: Hi There >> >> >>I have a couple of Denso Alternators that I want to convert to nonregulated alternators. I've seen a few different sites that discribe how to do this, but not one that has the same type of regulator that are on my alternators. Both alternators I have have a plastic regulator/plug housing. There are cooling The regulator bolts to the diodes and brushes. I'm sure someone has done one of these alternators, I was at the junk yard today and many of the import cars used an alternator of this disign. I have some photos if that helps. >> >> >>Thanks for any help. >> >> >>Cameron > > ________________________________ Message 41 ____________________________________ Time: 07:41:20 PM PST US From: "Dan Checkoway" "" Subject: AeroElectric-List: EMI solution for Dynon? --> AeroElectric-List message posted by: "Dan Checkoway" http://www.4emi.com Has anybody seen or played with these? Sure seems like an incredibly elegant way to go -- IF it works! )_( Dan RV-7 N714D http://www.rvproject.com ________________________________ Message 42 ____________________________________ Time: 07:56:58 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: start up/shut down procedure --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 06:12 PM 2/4/2004 -0600, you wrote: >--> AeroElectric-List message posted by: "AI Nut" > >Web site? http://www.aeroelectric.com Bob . . . ________________________________ Message 43 ____________________________________ Time: 08:05:28 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: OV protection for internally regulated alternators --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 06:54 PM 2/4/2004 -0600, you wrote: >--> AeroElectric-List message posted by: Jim Oke >alternators / ND alternator > >After following the Vans Nippon Denso saga for a day or so, I wonder if >anyone can comment on the smaller Denso alternator that AeroSport Power >supplies with their engines as an option. > >The one I received has a Nippon Denso tag as P/N 18504-6220 although it >seems to be manufactured by Ishikawajima as P/N 100211-1680 and marketed by >Denso. It has a B+ supply and can be run on a "single wire" control basis >although there is a warning light connection as well. > >The unit has worked well in my limited flying to date (RV-6A). I am using a >homebrew OVM with a B field contactor. > >And, no, I haven't experimented with a "battery dump" failure mode >experiment as yet. It's difficult to comment on any particular alternator until we're sure as to true root cause of the failures. The working hypothesis is that after-market regulators used by some re-build shops may not be as robust as the factory originals by ND and others. Probably the most revealing question to ask your alternator supplier . . . is this a new alternator or rebuilt? Not that rebuilt are automatically suspect . . . there are undoubtedly after-market regulators equal to OEM. Given that companies like ND sell MILLIONS of alternators per year, they can't afford a screwup that saves a few pennies per unit but opens doors to a ton of warranty claims. The after-market regulator folks are not so exposed. Their warranty covers only the regulator that costs them under $1 to build and they can always point to the fried chip and cry "load dump!". How many folks are going to know it's something the regulator SHOULD be able to tolerate? Don't do any "experimenting" until we have some data to work with. I've had conversation with two sets of folks about some testing. It won't happen until late next week at the earliest. Bob . . . ________________________________ Message 44 ____________________________________ Time: 08:10:21 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Connector for elevator trim servo --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 02:12 PM 2/4/2004 -0500, you wrote: >--> AeroElectric-List message posted by: N67BT@aol.com > >Photos and info on the Hirose connector I plan to use for the elevator trim >servo are posted on my web site. > >http://users.aol.com/n67bt > >This thing looks like just the ticket. What do you think Bob N.? > >They cost around $14 for the pair. Hirose is a good house. I've used their stuff on several occasions when I needed lots of conductors in a small package. Bob . . . ________________________________ Message 45 ____________________________________ Time: 08:24:40 PM PST US From: "Richard E. Tasker" Subject: Re: AeroElectric-List: BNC bulkhead pass-through connectors --> AeroElectric-List message posted by: "Richard E. Tasker" That is correct. Isolated means that the whole assembly that the BNC connectors connect to is electrically isolated from the mounting flange. Non-isolated means that the mounting flange is connected to the part of the connector that connects to the shield of the coax. Dick Tasker, RV9A #90572 Dave Morris wrote: >--> AeroElectric-List message posted by: Dave Morris > >I'm relatively sure it describes whether or not the outer conductor (where >the shield connects) is isolated from the panel mounting hardware or not. > >Dave Morris > > >At 06:16 PM 2/4/2004, you wrote: > > > >>--> AeroElectric-List message posted by: "LarryRobertHelming" >> >> >>In this reference, http://www.mpja.com/listitems.asp?dept=93&main=83 under >>the sub heading of GENDER CHANGER BNC CONNECTOR are two items that I do not >>understand and would like some help with what ISOLATED and NOT Isolated >>means with respect to BNC connectors. >> >>Larry >> >> >> >> > > > > ________________________________ Message 46 ____________________________________ Time: 09:01:08 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: EMI solution for Dynon? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:39 PM 2/4/2004 -0800, you wrote: >--> AeroElectric-List message posted by: "Dan Checkoway" > >http://www.4emi.com > >Has anybody seen or played with these? Sure seems like an incredibly >elegant way to go -- IF it works! They do work. I've had occasion to use them a couple of times in the past 20 years. Problem is that they're not cheap . . . and they use the same filtering technique on all pins whether the pin is a source/victim potential or not. For the most part, I've found it more economical to filter the pins that needed filtering with components appropriate to that pin's signal duties. Bob . . . ________________________________ Message 47 ____________________________________ Time: 09:08:37 PM PST US From: Dave Morris Subject: Re: AeroElectric-List: EMI solution for Dynon? --> AeroElectric-List message posted by: Dave Morris I'll believe it when I see the spectrum analyzer output. EMI is a complex problem and I don't think those little things will do much good. Dave Morris At 09:39 PM 2/4/2004, you wrote: >--> AeroElectric-List message posted by: "Dan Checkoway" > >http://www.4emi.com > >Has anybody seen or played with these? Sure seems like an incredibly >elegant way to go -- IF it works! > >)_( Dan >RV-7 N714D >http://www.rvproject.com > > ________________________________ Message 48 ____________________________________ Time: 09:51:12 PM PST US From: Jerzy Krasinski Subject: Re: AeroElectric-List: Converting a Denso Alternator --> AeroElectric-List message posted by: Jerzy Krasinski I opened my internaly regulated Mitsubishi, and I found one irregular block containing the brush holders and regulator, all epoxy potted inside a fragile looking piece of plastic. I thought about milling out the regulator but it is very difficult to hold that thing in the mill, and it looked that I would have to make a new brush holder from scratch. I have spent a day looking at it and I gave up. I put the alternator back together and I will try to attach transorbs or a big varistor for protection. The problem is that information about the transients included in http://www.sto-p.com/pfp/pfp-transients.htm#load is showing voltage approaching 100V and internal resistance of the source between 0.1 and 1 ohm. That would imply that current through the varistor or transorb limiting output voltage to several volts could reach several hundreds amps. That does not seem to make any sense, I would expect that the alternator would try to make the output current equal to the current just before removal of the load, and such current would reduce the peak voltage down to the normal output voltage. I will connect the protective elements and we will see if it works. Anyway, my Mitsubishi is nearly impossible to convert in a simple way. But maybe somebody solved that problem? I would appreciate some info. Thank you, Jerzy Mark Steitle wrote: >--> AeroElectric-List message posted by: Mark Steitle > >At 07:51 PM 2/3/2004 -0800, you wrote: > > >>--> AeroElectric-List message posted by: Hi There >> >> >>I have a couple of Denso Alternators that I want to convert to >>nonregulated alternators. >> >> > >Cameron, >I posted this procedure a while back, but couldn't find it in the >archives. So, here is the procedure I used to convert my two ND >alternators to external regulator mode. > >Mark >============================================= >Bob N. strongly recommends using externally regulated alternators only, or >modifying the internal regulator models so as to allow it to be shut down >if necessary. (Supposedly, a voltage run-away can happen in a few seconds.) >Problem is that the articles I read explaining how to convert the >internally regulated alternators to external regulation didn't work. (Did I >do something wrong?) I think I have worked out a simpler solution. The >objective here is to isolate the field windings from the diode bridge so >that the alternator can then be externally controlled. > >This is how I went about converting my alternators. First I removed the >back cover, exposing the diode bridge, regulator assy. and brush holder. >Then removed the regulator and brush holder and threw the regulator assy in >the trash. Next ........................ > >