---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 07/15/09: 40 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:13 AM - Re: Re: Automotive blade fuses? (Etienne Phillips) 2. 05:27 AM - D.A.R question about fuse access (Vincent Himsl) 3. 06:41 AM - Suitable diode replacement (Bob Barrow) 4. 06:41 AM - Re: Re: Automotive blade fuses? () 5. 06:41 AM - Re: D.A.R question about fuse access (Matt Prather) 6. 07:18 AM - Re: Suitable diode replacement (Bob White) 7. 07:52 AM - Re: D.A.R question about fuse access (Robert L. Nuckolls, III) 8. 08:14 AM - Re: D.A.R question about fuse access () 9. 08:24 AM - Fluctuating Amps (Charles Brame) 10. 08:39 AM - Re: D.A.R question about fuse access (Bret Smith) 11. 08:59 AM - Re: D.A.R question about fuse access (Matt Prather) 12. 09:41 AM - Re: Suitable diode replacement (Robert L. Nuckolls, III) 13. 09:47 AM - Re: Fluctuating Amps (Robert L. Nuckolls, III) 14. 10:03 AM - Fun flying after the medical is gone? (Robert L. Nuckolls, III) 15. 10:13 AM - Re: D.A.R question about fuse access (Bob Collins) 16. 10:56 AM - Re: D.A.R question about fuse access () 17. 11:45 AM - Re: D.A.R question about fuse access (Matt Prather) 18. 12:19 PM - Re: Automotive blade fuses? (heisan) 19. 12:22 PM - Re: D.A.R question about fuse access (thomas sargent) 20. 12:39 PM - Re: D.A.R question about fuse access (Hinde, Frank George (Corvallis)) 21. 12:40 PM - Re: Re: Automotive blade fuses? (thomas sargent) 22. 12:43 PM - Contacter, or not? (heisan) 23. 12:57 PM - Re: Contacter, or not? (Hinde, Frank George (Corvallis)) 24. 01:04 PM - Re: Contacter, or not? (heisan) 25. 01:20 PM - Re: D.A.R question about fuse access (Matt Prather) 26. 01:20 PM - Re: Automotive blade fuses? (Etienne Phillips) 27. 01:39 PM - Re: Re: Contacter, or not? (Hinde, Frank George (Corvallis)) 28. 01:41 PM - Re: Contacter, or not? (Matt Prather) 29. 01:41 PM - Re: Re: Contacter, or not? (Matt Prather) 30. 01:50 PM - Re: Contacter, or not? (Phil Birkelbach) 31. 01:50 PM - Re: D.A.R question about fuse access (Robert L. Nuckolls, III) 32. 01:55 PM - Re: D.A.R question about fuse access (Phil Birkelbach) 33. 02:14 PM - Re: Contacter, or not? (heisan) 34. 02:42 PM - Re: D.A.R question about fuse access () 35. 03:14 PM - Re: Re: Automotive blade fuses? (BobsV35B@aol.com) 36. 03:41 PM - Re: D.A.R question about fuse access (BobsV35B@aol.com) 37. 04:21 PM - Re: Contacter, or not? (Robert L. Nuckolls, III) 38. 04:23 PM - Re: Re: Automotive blade fuses? (thomas sargent) 39. 04:52 PM - Re: Contacter, or not? (Matt Prather) 40. 07:23 PM - glass fuses (Rick and Sandra Lark) ________________________________ Message 1 _____________________________________ Time: 03:13:05 AM PST US Subject: Re: AeroElectric-List: Re: Automotive blade fuses? From: Etienne Phillips Hi Justin They are available locally (as in Port Elizabeth) from Autozone... Not sure where abouts you are, but autozone is a chain store of sorts, so you may find them all over the country! Etienne 2009/7/14 heisan > > Thanks everybody. > > When I asked around here, everybody uses glass fuses or breakers. Two A&Ps > I chatted to said blade fuses were a bad idea (basically because it is > difficult to make the pretty! > > Nice to know that they will work, and are safe to use. > > Does anybody know of an on-line shop that sells decent blade fuse holders? > Options here are few and far between. > > Thanks, > Justin > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=252936#252936 > > ________________________________ Message 2 _____________________________________ Time: 05:27:09 AM PST US From: Vincent Himsl Subject: AeroElectric-List: D.A.R question about fuse access In planning the layout of your electrical system=2C I would suggest you pla ce your fuse blocks where you can answer 'yes' to the following question fr om a D.A.R: "Are you able to change fuses for critical instruments in flight?" (or som ething similar) Fortunately one of my fuse blocks=2C the one with my critical instruments =2C was within reach (under the panel) while in flight. Changing them in fl ight would be painful but possible. Before y'all blast off=2C realize the D.A.R is inspecting your airplane to see if it complies with Federal Regulations. If he asks you a question it i s because he believes he is required to. And regardless our collective thoughts and feelings about the question=2C i t is being asked. I have been on this list for years so I guess I should have anticipated thi s=2C but I have to admit the question caught me by surprise. I relay this s o you are not. Regards=2C Vince_Himsl RV8 N8432 Flying (10hours) _________________________________________________________________ Lauren found her dream laptop. Find the PC that=92s right for you. http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290 ________________________________ Message 3 _____________________________________ Time: 06:41:07 AM PST US From: Bob Barrow Subject: AeroElectric-List: Suitable diode replacement I have blown all 3 diodes on my S701-2 Cross Feed Contactor (through stupid ity!!) on my 12 volt Z14 architecture. They are all of the type 1N5400 (3 a mp 50 volt). I am having trouble getting replacements locally (Australia) f or these specific diodes and I was wondering if I could replace them with t he type 1N5404 (3 amp 400 volt) which is readily available. One of 1N5400 diodes on the Cross Feed Contactor is obviously specifically for voltage spike suppression across the contactor. I'm not sure whether th e voltage rating (breakdown voltage for reverse current) on this diode in p articular is actually an important factor for spike suppression or not. I'd appreciate feedback from any guru out there. _________________________________________________________________ View photos of singles in your area Click Here http://dating.ninemsn.com.au/search/search.aspx?exec=go&tp=q&gc=2&tr =1&lage=18&uage=55&cl=14&sl=0&dist=50&po=1&do=2&trackingid =1046138&r2s=1&_t=773166090&_r=WLM_EndText ________________________________ Message 4 _____________________________________ Time: 06:41:08 AM PST US Subject: RE: AeroElectric-List: Re: Automotive blade fuses? From: I've also seen these at Pep Boys if you're on the east coast. Glenn From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Etienne Phillips Sent: Wednesday, July 15, 2009 6:10 AM Subject: Re: AeroElectric-List: Re: Automotive blade fuses? Hi Justin They are available locally (as in Port Elizabeth) from Autozone... Not sure where abouts you are, but autozone is a chain store of sorts, so you may find them all over the country! Etienne 2009/7/14 heisan Thanks everybody. When I asked around here, everybody uses glass fuses or breakers. Two A&Ps I chatted to said blade fuses were a bad idea (basically because it is difficult to make the pretty! Nice to know that they will work, and are safe to use. Does anybody know of an on-line shop that sells decent blade fuse holders? Options here are few and far between. Thanks, Justin Read this topic online here: http://forums.matronics.com/viewtopic.php?p=252936#252936 h as List Un/Subscription, www.matronics.com/Navigator?AeroElectric-List" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List ronics.com/" target="_blank">http://forums.matronics.com Matt Dralle, List Admin. ==== ________________________________ Message 5 _____________________________________ Time: 06:41:17 AM PST US Subject: Re: AeroElectric-List: D.A.R question about fuse access From: "Matt Prather" Why did you design the airplane with any critical instruments? Good panel design dictates that there aren't any. It's a trick question.. Most certified single engine airplanes don't have a backup vacuum source. Nor a backup electrical system. An EFIS, a separate turn indicator, plus a (at least one of these having internal/backup/battery power) GPS provide as much (more) useful, overlapping information so that if any one item fails, you can still maintain control of the airplane. Changing fuses while in flight instead of maintaining positive control of the airplane sounds dangerous. Matt- > > In planning the layout of your electrical system, I would suggest you > place your fuse blocks where you can answer 'yes' to the following > question from a D.A.R: > > "Are you able to change fuses for critical instruments in flight?" (or > something similar) > > Fortunately one of my fuse blocks, the one with my critical instruments, > was within reach (under the panel) while in flight. Changing them in > flight would be painful but possible. > > Before y'all blast off, realize the D.A.R is inspecting your airplane to > see if it complies with Federal Regulations. If he asks you a question it > is because he believes he is required to. > > And regardless our collective thoughts and feelings about the question, it > is being asked. > > I have been on this list for years so I guess I should have anticipated > this, but I have to admit the question caught me by surprise. I relay this > so you are not. > > Regards, > Vince_Himsl > RV8 N8432 Flying (10hours) > > > _________________________________________________________________ > Lauren found her dream laptop. Find the PC thats right for you. > http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290 ________________________________ Message 6 _____________________________________ Time: 07:18:52 AM PST US From: Bob White Subject: Re: AeroElectric-List: Suitable diode replacement Hi Bob, The 1N5404 will work fine. Bob W. On Wed, 15 Jul 2009 23:25:52 +1000 Bob Barrow wrote: > > I have blown all 3 diodes on my S701-2 Cross Feed Contactor (through stupidity!!) on my 12 volt Z14 architecture. They are all of the type 1N5400 (3 amp 50 volt). I am having trouble getting replacements locally (Australia) for these specific diodes and I was wondering if I could replace them with the type 1N5404 (3 amp 400 volt) which is readily available. > > > > One of 1N5400 diodes on the Cross Feed Contactor is obviously specifically for voltage spike suppression across the contactor. I'm not sure whether the voltage rating (breakdown voltage for reverse current) on this diode in particular is actually an important factor for spike suppression or not. > > > > I'd appreciate feedback from any guru out there. > > _________________________________________________________________ > View photos of singles in your area Click Here > http://dating.ninemsn.com.au/search/search.aspx?exec=go&tp=q&gc=2&tr=1&lage=18&uage=55&cl=14&sl=0&dist=50&po=1&do=2&trackingid=1046138&r2s=1&_t=773166090&_r=WLM_EndText -- N93BD - Rotary Powered BD-4 - http://www.bob-white.com 3.8 Hours Total Time and holding Cables for your rotary installation - http://roblinstores.com/ ________________________________ Message 7 _____________________________________ Time: 07:52:40 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: D.A.R question about fuse access At 07:25 AM 7/15/2009, you wrote: >In planning the layout of your electrical system, I would suggest >you place your fuse blocks where you can answer 'yes' to the >following question from a D.A.R: > >"Are you able to change fuses for critical instruments in >flight?" (or something similar) This is a recurring concern that is lifted from the FARS. In 99% of the cases where "critical" is used in Part 23/25 it's referring to exploring the limits of some performance characteristics like load limits, single-engine handling qualities in a twin engine airplane, c.g. limits, etc. etc. In terms of criticality of electro-whizzies, the FARS are not enlightening. I suggest this is because while things like wing spars, engines and unstable aerodynamics can get you killed, the manner in which electrics affect the outcome of flight varies widely based on mission, weather and pilot skills. The DAY VFR J-3 has no critical electrics . . . in fact no electrics at all. The LAIV-P that routinely bores holes in crummy weather, at night and over mountains is entirely another matter. To begin, YOU need to assess criticality of any particular piece of hardware based on how YOU are going to use the airplane. Second, be aware that there are many ways that piece of equipment can quit working that DO NOT pop fuses or breakers. The simple logic behind this assertion suggests that spending any time locating fuses for easy replacement adds no value to the finished product. Finally, launching into the blue with a willingness to become a systems failure diagnostician and repair technician during a time when you really NEED some particular piece of stuff to be working comes with a high order of risk. The obvious solution is to design the system for FAILURE TOLERANCE . . . i.e. no matter what circumstances for which you plan to use the airplane, no single piece of necessary equipment is not backed up, i.e. your airplane has no critical systems. >Fortunately one of my fuse blocks, the one with my critical >instruments, was within reach (under the panel) while in flight. >Changing them in flight would be painful but possible. The best fix for this is move it where you CAN'T reach it. The tendency to think in terms of in-flight fuse replacement goes away and thinking about failure tolerance replaces it. . . . A good thing. >Before y'all blast off, realize the D.A.R is inspecting your >airplane to see if it complies with Federal Regulations. If he asks >you a question it is because he believes he is required to. If your talking about an owner built and maintained airplane, there are no regulations that affect configuration of the project. The only regulations that apply to OBAM aircraft are OPERATIONAL concerns rightfully levied because you must play in the same sandbox with the big guys. While operating in that environment, it should be transparent to everyone else that you're in an OBAM aircraft. You're behaviors and capabilities need to be the same as everyone else while seamlessly sharing the airspace. >And regardless our collective thoughts and feelings about the >question, it is being asked. > >I have been on this list for years so I guess I should have >anticipated this, but I have to admit the question caught me by >surprise. I relay this so you are not. The answer for anyone who might exercise a regulatory authority over your project is to explain why none of the equipment items in your airplane are ever "critical" to continued flight or comfortable termination of flight. This might be because for every situation in which you use the airplane, it matters not if ANY electrical item on the panel is working. Better yet, it might be the case because you have a plan-b in the hip pocket to deal with any failure of necessary equipment. Think of it like this: I've never owned an airplane with an electrical system in it (Our J-3 at 1K1 was not so blessed). Every time I go fly, it's in a rented airplane. As I walk up to that airplane, should I be ruminating on service history for the alternator? Should I check the logs for service difficulties? Do I want to check the warranty date sticker on the battery? With a rented airplane, there are MANY issues that are out of my direct supervision and control. THIS is why I have to rely on the integrity and skill of the airplane's owner to keep things up to snuff under the FARS. At the same time, I always fly with this stuff in my flight bag: http://aeroelectric.com/Pictures/Misc/Vacination_for_Dark_Panel_Syndrom.pdf So my personal assessment of criticality combined with the manner in which I use airplanes allows me to launch without concern for ANYTHING working on the panel. It's my plan-B, plan-C, etc to comfortably terminate the flight at airport of intended destination irrespective of whether or not the master switch is even turned on. I don't care if it's a C150 or an A36. I'm comfortable with NOT knowing if the electrical systems is 100% to my satisfaction. The mind set you need to adopt when dealing with the "learned elite" of aviation is NOT to argue with the applicability of any particular directives handed down from on high. Smile and explain that you've carefully thought through your system configuration. It's designed with your skill set and mission requirements in mind such that no single piece of equipment is "critical". All installed electro-whizzies are either (1) not necessary for comfortable termination of any anticipated flight or (2) backed up with totally independent capabilities. If YOU understand what you've achieved based on your planning and workmanship, then explaining it to a skeptical/un-informed inquisitor is easier. It's your confidence built upon understanding and planning that drives risk down for YOUR use of THAT airplane . . . NOT mindless adherence to vague, broad brush directives from a policy and procedures manual that doesn't apply to you anyhow. See chapter 17 of the 'Connection and any number of fuse/breaker/failure-tolerance discussions on the List archives and on http://aeroelectric.com. Understanding starts there. Confidence will follow. Bob . . . ________________________________ Message 8 _____________________________________ Time: 08:14:13 AM PST US Subject: RE: AeroElectric-List: D.A.R question about fuse access From: Matt, Ok, I have 3 EFIS displays, two alternators, two batteries & two internal batteries within the EFIS's, a drop down panel to access all fuses (within easy reach of the pilot) and a compliment of spare LED fuses. I'm thinking of adding a PEZ like dispenser for fuses below my seat with lighted push buttons with numbers so I can pop them on demand like a soda machine. So how should I respond to the DAR? I totally agree, with one caveat - if you need to change fuses in flight, be sure you have the autopilot turned on with the traffic alerts turned on. If you're flying IFR you already have someone watching your back for the 1 minute it takes. If you can't find the problem in 1 minute and it's not critical, fix it on the ground. Better yet, fly with a buddy and make him/her perform the swap. Glenn -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Matt Prather Sent: Wednesday, July 15, 2009 9:35 AM Subject: Re: AeroElectric-List: D.A.R question about fuse access Why did you design the airplane with any critical instruments? Good panel design dictates that there aren't any. It's a trick question.. Most certified single engine airplanes don't have a backup vacuum source. Nor a backup electrical system. An EFIS, a separate turn indicator, plus a (at least one of these having internal/backup/battery power) GPS provide as much (more) useful, overlapping information so that if any one item fails, you can still maintain control of the airplane. Changing fuses while in flight instead of maintaining positive control of the airplane sounds dangerous. Matt- > > In planning the layout of your electrical system, I would suggest you > place your fuse blocks where you can answer 'yes' to the following > question from a D.A.R: > > "Are you able to change fuses for critical instruments in flight?" (or > something similar) > > Fortunately one of my fuse blocks, the one with my critical instruments, > was within reach (under the panel) while in flight. Changing them in > flight would be painful but possible. > > Before y'all blast off, realize the D.A.R is inspecting your airplane to > see if it complies with Federal Regulations. If he asks you a question it > is because he believes he is required to. > > And regardless our collective thoughts and feelings about the question, it > is being asked. > > I have been on this list for years so I guess I should have anticipated > this, but I have to admit the question caught me by surprise. I relay this > so you are not. > > Regards, > Vince_Himsl > RV8 N8432 Flying (10hours) > > > _________________________________________________________________ > Lauren found her dream laptop. Find the PC that's right for you. > http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290 ________________________________ Message 9 _____________________________________ Time: 08:24:37 AM PST US From: Charles Brame Subject: AeroElectric-List: Fluctuating Amps Bob, et. al., According to my MicroVision engine monitor, the amps on my RV-6 vary almost constantly from "0" to around "17." A normal load should be about "7." The voltage holds very steady at 13.8 monitored from my essential bus, and all my avionics and other electrical equipment seems to work as advertised. I have a B&C 60 amp alternator and a generic Ford voltage regulator. The amperage is measured via a Hall sensor on the main alternator feed line and I have not been able to locate any loose wires or bad connections. Any ideas of what the problem is? Is there an alternator or voltage regulator failure in the offing? Charlie Brame RV-6A N11CB San Antonio ________________________________ Message 10 ____________________________________ Time: 08:39:55 AM PST US From: "Bret Smith" Subject: Re: AeroElectric-List: D.A.R question about fuse access Well said! Bret Smith do not archive ----- Original Message ----- From: Robert L. Nuckolls, III To: aeroelectric-list@matronics.com Sent: Wednesday, July 15, 2009 10:51 AM Subject: Re: AeroElectric-List: D.A.R question about fuse access At 07:25 AM 7/15/2009, you wrote: In planning the layout of your electrical system, I would suggest you place your fuse blocks where you can answer 'yes' to the following question from a D.A.R: "Are you able to change fuses for critical instruments in flight?" (or something similar) The obvious solution is to design the system for FAILURE TOLERANCE . . . i.e. no matter what circumstances for which you plan to use the airplane, no single piece of necessary equipment is not backed up, i.e. your airplane has no critical systems. ________________________________ Message 11 ____________________________________ Time: 08:59:09 AM PST US Subject: RE: AeroElectric-List: D.A.R question about fuse access From: "Matt Prather" Depending on how the circuits are designed, it sounds like you're set for most ops.. I like the AP idea. Arguably, an AP should be on any airplane used for IFR. They are relatively cheap nowadays. What's the procedure if you suspect the fuse for the AP blew? What happens if you accidentally pull the wrong fuse? Do you lose another piece of 'critical equipment'? Matt- > > Matt, > > Ok, I have 3 EFIS displays, two alternators, two batteries & two > internal batteries within the EFIS's, a drop down panel to access all > fuses (within easy reach of the pilot) and a compliment of spare LED > fuses. I'm thinking of adding a PEZ like dispenser for fuses below my > seat with lighted push buttons with numbers so I can pop them on demand > like a soda machine. > > So how should I respond to the DAR? > > I totally agree, with one caveat - if you need to change fuses in > flight, be sure you have the autopilot turned on with the traffic alerts > turned on. If you're flying IFR you already have someone watching your > back for the 1 minute it takes. If you can't find the problem in 1 > minute and it's not critical, fix it on the ground. Better yet, fly with > a buddy and make him/her perform the swap. > > Glenn > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Matt > Prather > Sent: Wednesday, July 15, 2009 9:35 AM > To: aeroelectric-list@matronics.com > Subject: Re: AeroElectric-List: D.A.R question about fuse access > > > > Why did you design the airplane with any critical instruments? Good > panel > design dictates that there aren't any. > > It's a trick question.. Most certified single engine airplanes don't > have > a backup vacuum source. Nor a backup electrical system. > > An EFIS, a separate turn indicator, plus a (at least one of these having > internal/backup/battery power) GPS provide as much (more) useful, > overlapping information so that if any one item fails, you can still > maintain control of the airplane. > > Changing fuses while in flight instead of maintaining positive control > of > the airplane sounds dangerous. > > > Matt- > >> >> In planning the layout of your electrical system, I would suggest you >> place your fuse blocks where you can answer 'yes' to the following >> question from a D.A.R: >> >> "Are you able to change fuses for critical instruments in flight?" > (or >> something similar) >> >> Fortunately one of my fuse blocks, the one with my critical > instruments, >> was within reach (under the panel) while in flight. Changing them in >> flight would be painful but possible. >> >> Before y'all blast off, realize the D.A.R is inspecting your airplane > to >> see if it complies with Federal Regulations. If he asks you a question > it >> is because he believes he is required to. >> >> And regardless our collective thoughts and feelings about the > question, it >> is being asked. >> >> I have been on this list for years so I guess I should have > anticipated >> this, but I have to admit the question caught me by surprise. I relay > this >> so you are not. >> >> Regards, >> Vince_Himsl >> RV8 N8432 Flying (10hours) >> >> >> >> _________________________________________________________________ >> Lauren found her dream laptop. Find the PC that's right for you. >> http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290 > > ________________________________ Message 12 ____________________________________ Time: 09:41:59 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Suitable diode replacement >One of 1N5400 diodes on the Cross Feed Contactor is obviously >specifically for voltage spike suppression across the contactor. Actually, only ONE of the three is for coil spike suppression. The other two are for power steering. The idea is that one should be able to close the contactor using power from either side of the system. I.e. the powered side gets a contactor closed to support the non-powered side. As long as the diodes are rated at 50v or more, ANY diode will work in these applications for contactors. Higher current ratings are called for with devices like the normal feed path for the e-bus . . . which is not needed on Z-14 systems. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 13 ____________________________________ Time: 09:47:16 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Fluctuating Amps At 10:20 AM 7/15/2009, you wrote: > >Bob, et. al., > >According to my MicroVision engine monitor, the amps on my RV-6 vary >almost constantly from "0" to around "17." A normal load should be >about "7." The voltage holds very steady at 13.8 monitored from my >essential bus, and all my avionics and other electrical equipment >seems to work as advertised. I have a B&C 60 amp alternator and a >generic Ford voltage regulator. The amperage is measured via a Hall >sensor on the main alternator feed line and I have not been able to >locate any loose wires or bad connections. > >Any ideas of what the problem is? Is there an alternator or voltage >regulator failure in the offing? The first thing to do is confirm the variability of the display. If the voltage readings are steady then the regulator is fine. I'd do a temporary installation of another ammeter in the b-lead to confirm the micro-vision system performance. Alternatively, you could simply remove the current sensor all together and quit worrying about it. Ammeters are more useful as a diagnostic tool and then only if they're know to be trustworthy. If your voltage is stable under all system load conditions, probability is that the ammeter is flakey. Try taking the b-lead wire out of the sensor and see if it's still bouncing around with "zero" excitation. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 14 ____________________________________ Time: 10:03:56 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Fun flying after the medical is gone? http://www.youtube.com/watch?v=SDbQ5xvsrIU Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 15 ____________________________________ Time: 10:13:56 AM PST US From: "Bob Collins" Subject: RE: AeroElectric-List: D.A.R question about fuse access I wonder how a DAR would look upon Vertical Power. No fuses. You have a control box in the panel that you can reset a "failed" circuit, but that's it. There's no ability to "change fuses in flight". _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Wednesday, July 15, 2009 9:51 AM Subject: Re: AeroElectric-List: D.A.R question about fuse access At 07:25 AM 7/15/2009, you wrote: In planning the layout of your electrical system, I would suggest you place your fuse blocks where you can answer 'yes' to the following question from a D.A.R: "Are you able to change fuses for critical instruments in flight?" (or something similar) This is a recurring concern that is lifted from the FARS. In 99% of the cases where "critical" is used in Part 23/25 it's referring to exploring the limits of some performance characteristics like load limits, single-engine handling qualities in a twin engine airplane, c.g. limits, etc. etc. In terms of criticality of electro-whizzies, the FARS are not enlightening. I suggest this is because while things like wing spars, engines and unstable aerodynamics can get you killed, the manner in which electrics affect the outcome of flight varies widely based on mission, weather and pilot skills. The DAY VFR J-3 has no critical electrics . . . in fact no electrics at all. The LAIV-P that routinely bores holes in crummy weather, at night and over mountains is entirely another matter. To begin, YOU need to assess criticality of any particular piece of hardware based on how YOU are going to use the airplane. Second, be aware that there are many ways that piece of equipment can quit working that DO NOT pop fuses or breakers. The simple logic behind this assertion suggests that spending any time locating fuses for easy replacement adds no value to the finished product. Finally, launching into the blue with a willingness to become a systems failure diagnostician and repair technician during a time when you really NEED some particular piece of stuff to be working comes with a high order of risk. The obvious solution is to design the system for FAILURE TOLERANCE . . . i.e. no matter what circumstances for which you plan to use the airplane, no single piece of necessary equipment is not backed up, i.e. your airplane has no critical systems. Fortunately one of my fuse blocks, the one with my critical instruments, was within reach (under the panel) while in flight. Changing them in flight would be painful but possible. The best fix for this is move it where you CAN'T reach it. The tendency to think in terms of in-flight fuse replacement goes away and thinking about failure tolerance replaces it. . . . A good thing. Before y'all blast off, realize the D.A.R is inspecting your airplane to see if it complies with Federal Regulations. If he asks you a question it is because he believes he is required to. If your talking about an owner built and maintained airplane, there are no regulations that affect configuration of the project. The only regulations that apply to OBAM aircraft are OPERATIONAL concerns rightfully levied because you must play in the same sandbox with the big guys. While operating in that environment, it should be transparent to everyone else that you're in an OBAM aircraft. You're behaviors and capabilities need to be the same as everyone else while seamlessly sharing the airspace. And regardless our collective thoughts and feelings about the question, it is being asked. I have been on this list for years so I guess I should have anticipated this, but I have to admit the question caught me by surprise. I relay this so you are not. The answer for anyone who might exercise a regulatory authority over your project is to explain why none of the equipment items in your airplane are ever "critical" to continued flight or comfortable termination of flight. This might be because for every situation in which you use the airplane, it matters not if ANY electrical item on the panel is working. Better yet, it might be the case because you have a plan-b in the hip pocket to deal with any failure of necessary equipment. Think of it like this: I've never owned an airplane with an electrical system in it (Our J-3 at 1K1 was not so blessed). Every time I go fly, it's in a rented airplane. As I walk up to that airplane, should I be ruminating on service history for the alternator? Should I check the logs for service difficulties? Do I want to check the warranty date sticker on the battery? With a rented airplane, there are MANY issues that are out of my direct supervision and control. THIS is why I have to rely on the integrity and skill of the airplane's owner to keep things up to snuff under the FARS. At the same time, I always fly with this stuff in my flight bag: http://aeroelectric.com/Pictures/Misc/Vacination_for_Dark_Panel_Syndrom.pdf So my personal assessment of criticality combined with the manner in which I use airplanes allows me to launch without concern for ANYTHING working on the panel. It's my plan-B, plan-C, etc to comfortably terminate the flight at airport of intended destination irrespective of whether or not the master switch is even turned on. I don't care if it's a C150 or an A36. I'm comfortable with NOT knowing if the electrical systems is 100% to my satisfaction. The mind set you need to adopt when dealing with the "learned elite" of aviation is NOT to argue with the applicability of any particular directives handed down from on high. Smile and explain that you've carefully thought through your system configuration. It's designed with your skill set and mission requirements in mind such that no single piece of equipment is "critical". All installed electro-whizzies are either (1) not necessary for comfortable termination of any anticipated flight or (2) backed up with totally independent capabilities. If YOU understand what you've achieved based on your planning and workmanship, then explaining it to a skeptical/un-informed inquisitor is easier. It's your confidence built upon understanding and planning that drives risk down for YOUR use of THAT airplane . . . NOT mindless adherence to vague, broad brush directives from a policy and procedures manual that doesn't apply to you anyhow. See chapter 17 of the 'Connection and any number of fuse/breaker/failure-tolerance discussions on the List archives and on http://aeroelectric.com . Understanding starts there. Confidence will follow. Bob . . . ________________________________ Message 16 ____________________________________ Time: 10:56:43 AM PST US Subject: RE: AeroElectric-List: D.A.R question about fuse access From: Matt, However silly it may appear I like the led approach to avoid choosing an un-blown/wrong fuse. On my fuse buses, each fuse is additionally labeled to assist in locating the right fuse. To me pulling the wrong fuse is no worse than pulling a breaker accidentally. Turn off the affected device, plug the fuse back in and re-start the device - don't do that again. I have dual ignition with one side slaved to the second battery. The engine will keep running no matter what breaker is pulled. Since my AP is internal to the Dynon and runs on the Dynon network, it will fly on battery for about an hour, thus giving me enough warning to get down. If one has lots of blown fuses and has trouble picking the right one, you either have a bigger issue or you're just really ignorant about maintenance. Assuming only one is blown, let's fix it and maybe avoid lots of headaches. The nice thing about having internal batteries within the EFIS is that nothing changes while you scurry to either change the fuse or land and repair - even for the AP. If I couldn't isolate the problem by replacing the fuse - I'd just land. Kind-o-like the ole' circuit breaker theory - if it blows once you reset it. If it blows twice, you leave it. Glenn -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Matt Prather Sent: Wednesday, July 15, 2009 11:50 AM Subject: RE: AeroElectric-List: D.A.R question about fuse access Depending on how the circuits are designed, it sounds like you're set for most ops.. I like the AP idea. Arguably, an AP should be on any airplane used for IFR. They are relatively cheap nowadays. What's the procedure if you suspect the fuse for the AP blew? What happens if you accidentally pull the wrong fuse? Do you lose another piece of 'critical equipment'? Matt- > > Matt, > > Ok, I have 3 EFIS displays, two alternators, two batteries & two > internal batteries within the EFIS's, a drop down panel to access all > fuses (within easy reach of the pilot) and a compliment of spare LED > fuses. I'm thinking of adding a PEZ like dispenser for fuses below my > seat with lighted push buttons with numbers so I can pop them on demand > like a soda machine. > > So how should I respond to the DAR? > > I totally agree, with one caveat - if you need to change fuses in > flight, be sure you have the autopilot turned on with the traffic alerts > turned on. If you're flying IFR you already have someone watching your > back for the 1 minute it takes. If you can't find the problem in 1 > minute and it's not critical, fix it on the ground. Better yet, fly with > a buddy and make him/her perform the swap. > > Glenn > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Matt > Prather > Sent: Wednesday, July 15, 2009 9:35 AM > To: aeroelectric-list@matronics.com > Subject: Re: AeroElectric-List: D.A.R question about fuse access > > > > Why did you design the airplane with any critical instruments? Good > panel > design dictates that there aren't any. > > It's a trick question.. Most certified single engine airplanes don't > have > a backup vacuum source. Nor a backup electrical system. > > An EFIS, a separate turn indicator, plus a (at least one of these having > internal/backup/battery power) GPS provide as much (more) useful, > overlapping information so that if any one item fails, you can still > maintain control of the airplane. > > Changing fuses while in flight instead of maintaining positive control > of > the airplane sounds dangerous. > > > Matt- > >> >> In planning the layout of your electrical system, I would suggest you >> place your fuse blocks where you can answer 'yes' to the following >> question from a D.A.R: >> >> "Are you able to change fuses for critical instruments in flight?" > (or >> something similar) >> >> Fortunately one of my fuse blocks, the one with my critical > instruments, >> was within reach (under the panel) while in flight. Changing them in >> flight would be painful but possible. >> >> Before y'all blast off, realize the D.A.R is inspecting your airplane > to >> see if it complies with Federal Regulations. If he asks you a question > it >> is because he believes he is required to. >> >> And regardless our collective thoughts and feelings about the > question, it >> is being asked. >> >> I have been on this list for years so I guess I should have > anticipated >> this, but I have to admit the question caught me by surprise. I relay > this >> so you are not. >> >> Regards, >> Vince_Himsl >> RV8 N8432 Flying (10hours) >> >> >> >> _________________________________________________________________ >> Lauren found her dream laptop. Find the PC that's right for you. >> http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290 > > ________________________________ Message 17 ____________________________________ Time: 11:45:23 AM PST US Subject: RE: AeroElectric-List: D.A.R question about fuse access From: "Matt Prather" Certainly there are situations where I might mess around with diagnostics while in flight. Many a flight there's nothing better to do besides drone on. Especially if it's severe-clear for the length of the mission. If it's dark and/or stormy, I'd be much more reluctant to do anything besides hunker down and continue the flight with what's left. In my limited experience on the needles, distraction is something I don't need.. Out of curiosity, is the AP servo powered by the instrument or does it have a separate power source? Matt- > > Matt, > > However silly it may appear I like the led approach to avoid choosing an > un-blown/wrong fuse. On my fuse buses, each fuse is additionally labeled > to assist in locating the right fuse. To me pulling the wrong fuse is no > worse than pulling a breaker accidentally. Turn off the affected device, > plug the fuse back in and re-start the device - don't do that again. I > have dual ignition with one side slaved to the second battery. The > engine will keep running no matter what breaker is pulled. > > Since my AP is internal to the Dynon and runs on the Dynon network, it > will fly on battery for about an hour, thus giving me enough warning to > get down. If one has lots of blown fuses and has trouble picking the > right one, you either have a bigger issue or you're just really ignorant > about maintenance. Assuming only one is blown, let's fix it and maybe > avoid lots of headaches. > > The nice thing about having internal batteries within the EFIS is that > nothing changes while you scurry to either change the fuse or land and > repair - even for the AP. If I couldn't isolate the problem by replacing > the fuse - I'd just land. Kind-o-like the ole' circuit breaker theory - > if it blows once you reset it. If it blows twice, you leave it. > > Glenn > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Matt > Prather > Sent: Wednesday, July 15, 2009 11:50 AM > To: aeroelectric-list@matronics.com > Subject: RE: AeroElectric-List: D.A.R question about fuse access > > > > Depending on how the circuits are designed, it sounds like you're set > for > most ops.. > > I like the AP idea. Arguably, an AP should be on any airplane used for > IFR. They are relatively cheap nowadays. What's the procedure if you > suspect the fuse for the AP blew? > > What happens if you accidentally pull the wrong fuse? Do you lose > another > piece of 'critical equipment'? > > > Matt- > >> >> Matt, >> >> Ok, I have 3 EFIS displays, two alternators, two batteries & two >> internal batteries within the EFIS's, a drop down panel to access all >> fuses (within easy reach of the pilot) and a compliment of spare LED >> fuses. I'm thinking of adding a PEZ like dispenser for fuses below my >> seat with lighted push buttons with numbers so I can pop them on > demand >> like a soda machine. >> >> So how should I respond to the DAR? >> >> I totally agree, with one caveat - if you need to change fuses in >> flight, be sure you have the autopilot turned on with the traffic > alerts >> turned on. If you're flying IFR you already have someone watching your >> back for the 1 minute it takes. If you can't find the problem in 1 >> minute and it's not critical, fix it on the ground. Better yet, fly > with >> a buddy and make him/her perform the swap. >> >> Glenn >> >> -----Original Message----- >> From: owner-aeroelectric-list-server@matronics.com >> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of > Matt >> Prather >> Sent: Wednesday, July 15, 2009 9:35 AM >> To: aeroelectric-list@matronics.com >> Subject: Re: AeroElectric-List: D.A.R question about fuse access >> >> >> >> Why did you design the airplane with any critical instruments? Good >> panel >> design dictates that there aren't any. >> >> It's a trick question.. Most certified single engine airplanes don't >> have >> a backup vacuum source. Nor a backup electrical system. >> >> An EFIS, a separate turn indicator, plus a (at least one of these > having >> internal/backup/battery power) GPS provide as much (more) useful, >> overlapping information so that if any one item fails, you can still >> maintain control of the airplane. >> >> Changing fuses while in flight instead of maintaining positive control >> of >> the airplane sounds dangerous. >> >> >> Matt- >> >>> >>> In planning the layout of your electrical system, I would suggest you >>> place your fuse blocks where you can answer 'yes' to the following >>> question from a D.A.R: >>> >>> "Are you able to change fuses for critical instruments in flight?" >> (or >>> something similar) >>> >>> Fortunately one of my fuse blocks, the one with my critical >> instruments, >>> was within reach (under the panel) while in flight. Changing them in >>> flight would be painful but possible. >>> >>> Before y'all blast off, realize the D.A.R is inspecting your airplane >> to >>> see if it complies with Federal Regulations. If he asks you a > question >> it >>> is because he believes he is required to. >>> >>> And regardless our collective thoughts and feelings about the >> question, it >>> is being asked. >>> >>> I have been on this list for years so I guess I should have >> anticipated >>> this, but I have to admit the question caught me by surprise. I relay >> this >>> so you are not. >>> >>> Regards, >>> Vince_Himsl >>> RV8 N8432 Flying (10hours) >>> >>> >>> >>> _________________________________________________________________ >>> Lauren found her dream laptop. Find the PC that's right for you. >>> http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290 >> >> >> >> >> >> >> >> >> >> >> >> > > ________________________________ Message 18 ____________________________________ Time: 12:19:45 PM PST US Subject: AeroElectric-List: Re: Automotive blade fuses? From: "heisan" Thanks for all the info. I will try AutoZone locally on Friday. If that doesn't work, I will order from one of the on-line shops. You guys in the USA really have it all! Thanks, Justin Read this topic online here: http://forums.matronics.com/viewtopic.php?p=253201#253201 ________________________________ Message 19 ____________________________________ Time: 12:22:36 PM PST US Subject: Re: AeroElectric-List: D.A.R question about fuse access From: thomas sargent I'm confused by this thread. Are you telling me that the D.A.R. is going to REQUIRE that my fuse block be accessible in flight? (Mine isn't.) Or are you just telling me I need to have a rap prepared to respond to the question. -- Tom Sargent ________________________________ Message 20 ____________________________________ Time: 12:39:59 PM PST US From: "Hinde, Frank George (Corvallis)" Subject: RE: AeroElectric-List: D.A.R question about fuse access DAR's sometimes have an "its my way or the highway" approach..But this is v ery rare. You just need to tell him there is no one fuse that will take out your abil ity to fly or navigate..And you have no intention of changing fuses in flig ht. None of my 3 fuse boxes are accesible and the idea of changing a fuse while being bounced around in IMC is ludicrous in my mind. Frank RV7a IFR, elctric fuel pumps only, totally electrically dependant. ________________________________ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectr ic-list-server@matronics.com] On Behalf Of thomas sargent Sent: Wednesday, July 15, 2009 12:19 PM Subject: Re: AeroElectric-List: D.A.R question about fuse access I'm confused by this thread. Are you telling me that the D.A.R. is going t o REQUIRE that my fuse block be accessible in flight? (Mine isn't.) Or are you just telling me I need to have a rap prepared to respond to the questio n. -- Tom Sargent ________________________________ Message 21 ____________________________________ Time: 12:40:39 PM PST US Subject: Re: AeroElectric-List: Re: Automotive blade fuses? From: thomas sargent Autozone has them, but only in values used commonly in cars. For your plane you will need a lot of small values - 1 or 2 or 3 amps. I doubt you'll find those at autozone or checker. B&C Specialty has them. On Wed, Jul 15, 2009 at 12:17 PM, heisan wrote: > > Thanks for all the info. > > I will try AutoZone locally on Friday. If that doesn't work, I will order > from one of the on-line shops. > > You guys in the USA really have it all! > > Thanks, > Justin > > -- Tom Sargent ________________________________ Message 22 ____________________________________ Time: 12:43:14 PM PST US Subject: AeroElectric-List: Contacter, or not? From: "heisan" After all the great info and advice I got on the fuses, I thought I would try asking about contacters too [Wink] . The aircraft manufacturer, and the engine manual both give a wiring diagram that does NOT include a master contacter. The battery positive goes directly to a master switch, and then to the main bus. This is the first time I have seen a configuration like this (without the contacter). What are the advantages, and disadvantages of doing it this way? My maximum current draw is around 10A, so well within the continuous current range of a small toggle switch. Thanks! Justin Read this topic online here: http://forums.matronics.com/viewtopic.php?p=253209#253209 ________________________________ Message 23 ____________________________________ Time: 12:57:25 PM PST US From: "Hinde, Frank George (Corvallis)" Subject: RE: AeroElectric-List: Contacter, or not? Where does the starter current go?..Usually it goes through the master contactor..You won't be sending that kind of current through a normal toggle switch..well more than once anyway...:) -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of heisan Sent: Wednesday, July 15, 2009 12:42 PM Subject: AeroElectric-List: Contacter, or not? --> After all the great info and advice I got on the fuses, I thought I would try asking about contacters too [Wink] . The aircraft manufacturer, and the engine manual both give a wiring diagram that does NOT include a master contacter. The battery positive goes directly to a master switch, and then to the main bus. This is the first time I have seen a configuration like this (without the contacter). What are the advantages, and disadvantages of doing it this way? My maximum current draw is around 10A, so well within the continuous current range of a small toggle switch. Thanks! Justin Read this topic online here: http://forums.matronics.com/viewtopic.php?p=253209#253209 ________________________________ Message 24 ____________________________________ Time: 01:04:05 PM PST US Subject: AeroElectric-List: Re: Contacter, or not? From: "heisan" frank.hinde(at)hp.com wrote: > Where does the starter current go?..Usually it goes through the master contactor..You won't be sending that kind of current through a normal toggle switch..well more than once anyway...:) > > -- Ah - forgot to mention - the starter has a built in solenoid. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=253216#253216 ________________________________ Message 25 ____________________________________ Time: 01:20:21 PM PST US Subject: RE: AeroElectric-List: D.A.R question about fuse access From: "Matt Prather" I like this answer. I suspect that many DAR's will be happy that you have a rational answer to such a question - indicating that you have considered and understand the issues involved. Regards, Matt- > DAR's sometimes have an "its my way or the highway" approach..But this is > very rare. > > You just need to tell him there is no one fuse that will take out your > ability to fly or navigate..And you have no intention of changing fuses in > flight. > > None of my 3 fuse boxes are accesible and the idea of changing a fuse > while being bounced around in IMC is ludicrous in my mind. > > > Frank RV7a IFR, elctric fuel pumps only, totally electrically dependant. > > > ________________________________ > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of thomas > sargent > Sent: Wednesday, July 15, 2009 12:19 PM > To: aeroelectric-list@matronics.com > Subject: Re: AeroElectric-List: D.A.R question about fuse access > > > I'm confused by this thread. Are you telling me that the D.A.R. is going > to REQUIRE that my fuse block be accessible in flight? (Mine isn't.) Or > are you just telling me I need to have a rap prepared to respond to the > question. > > > -- > Tom Sargent > > ________________________________ Message 26 ____________________________________ Time: 01:20:22 PM PST US From: Etienne Phillips Subject: Re: AeroElectric-List: Automotive blade fuses? Hi all When I suggested Autozone, I was referring to Autozone South Africa, not AutoZone USA. As Justin is a fellow Dark-Continent (Africa for those who are not familiar with the expression) dweller, I can appreciate the lack of local availability of certain seemingly easily obtainable aviation bits and pieces, unless you're happy spending 8-10 times the items value in shipping. I'm pretty sure the smaller values are available, and certainly any cable fault will be able to pop a 5A fuse... If you want it to blow at a lower value than that, then you'll probably find those fuses to be a bit harder to find. But there's no reason you have to import the fuse holder from the opposite side of the planet just because that's where the fuses will eventually need to come from. Etienne :-) On 15 Jul 2009, at 9:38 PM, thomas sargent wrote: > Autozone has them, but only in values used commonly in cars. For > your plane you will need a lot of small values - 1 or 2 or 3 amps. > I doubt you'll find those at autozone or checker. B&C Specialty > has them. > > On Wed, Jul 15, 2009 at 12:17 PM, heisan > wrote: > > > Thanks for all the info. > > I will try AutoZone locally on Friday. If that doesn't work, I > will order from one of the on-line shops. > > You guys in the USA really have it all! > > Thanks, > Justin > > > -- > Tom Sargent > > ________________________________ Message 27 ____________________________________ Time: 01:39:52 PM PST US From: "Hinde, Frank George (Corvallis)" Subject: RE: AeroElectric-List: Re: Contacter, or not? So there is a separate cable that comes directly from the battery and goes to the starter solenoid..I.e bypasses the switch? The reason I ask is cus useually the starter cable goes through the master contactor, then through the starter contactor then to the starter. I.e the starter cable usually goes through the master...At least on "Proper" airplanes..:) Sounds like you have an automotive setup?..You could also have a starter solenoid with this setup if you are uncomfortable with the starter cable being permanently hot. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of heisan Sent: Wednesday, July 15, 2009 1:03 PM Subject: AeroElectric-List: Re: Contacter, or not? --> frank.hinde(at)hp.com wrote: > Where does the starter current go?..Usually it goes through the master > contactor..You won't be sending that kind of current through a normal > toggle switch..well more than once anyway...:) > > -- Ah - forgot to mention - the starter has a built in solenoid. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=253216#253216 ________________________________ Message 28 ____________________________________ Time: 01:41:38 PM PST US Subject: Re: AeroElectric-List: Contacter, or not? From: "Matt Prather" With a peak current demand of 10A, I think you have a few options.. - Use a small(er) relay mounted close (6") to the battery. Mount your distribution bus anywhere you wish. This is basically a scaled-down version of existing architectures and provides all of the normal Z functionality. This is how my hand-started Varieze is setup. - If your battery is located close to the pilot's seat, you may be able to replace the battery relay with a manually operated battery switch. Cable operated switches have been discussed here in the past. - Use a battery bus mounted close to the battery. This is fine if you don't care about being able to make the whole system "cold" with one switch. - Use an appropriately sized inline fuse to feed the battery to a bus which is located elsewhere in the plane. This is probably OK if none of the electrical equipment is "critical to continued flight".. Faulting the fat feeder would cause it's protection to open up, causing all your electrical stuff to go dark. Using a relay of any type (esp a fat contactor) causes an extra load on the electrical system. If your sole source of power is a small PM dynamo, every watt starts to add up. Small relays only draw on the order of 100mA - less than 1% of the B&C dynamo on my O-200 - an acceptable load.. Regards, Matt- > > After all the great info and advice I got on the fuses, I thought I would > try asking about contacters too [Wink] . > > The aircraft manufacturer, and the engine manual both give a wiring diagram that does NOT include a master contacter. The battery positive goes directly to a master switch, and then to the main bus. > > This is the first time I have seen a configuration like this (without the > contacter). What are the advantages, and disadvantages of doing it this way? My maximum current draw is around 10A, so well within the continuous > current range of a small toggle switch. > > Thanks! > Justin > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=253209#253209 > > ________________________________ Message 29 ____________________________________ Time: 01:41:49 PM PST US Subject: Re: AeroElectric-List: Re: Contacter, or not? From: "Matt Prather" If your battery is located any significant distance from your starter, you need a heavy relay or heavy switch.. It's bad practice to have a long unprotected cable in the airplane which can't otherwise be made cold (via a switch or contactor). Regards, Matt- > > > frank.hinde(at)hp.com wrote: >> Where does the starter current go?..Usually it goes through the master >> contactor..You won't be sending that kind of current through a normal >> toggle switch..well more than once anyway...:) >> >> -- > > > Ah - forgot to mention - the starter has a built in solenoid. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=253216#253216 > > ________________________________ Message 30 ____________________________________ Time: 01:50:32 PM PST US From: Phil Birkelbach Subject: Re: AeroElectric-List: Contacter, or not? For only 10 Amps go with the switch. It takes almost an amp of current to hold the master contactor closed so you'd be using ~10% of your power just to keep the power on. One advantage to a master contactor is that the big fat wire that doesn't have a fuse on it can be very short. You can replicate this for 10A with an automotive relay near the battery and a small wire coming back to the switch, but that is one more thing that can fail. If it were me, I'd probably just put a fusible link near the battery, then run the wire from that to the switch and then to the main buss. Simple is good! Phil Birkelbach Houston RV7 - 727WB phil@petrasoft.net http://www.myrv7.com/ On Jul 15, 2009, at 2:42 PM, heisan wrote: > > > > After all the great info and advice I got on the fuses, I thought I > would try asking about contacters too [Wink] . > > The aircraft manufacturer, and the engine manual both give a wiring > diagram that does NOT include a master contacter. The battery > positive goes directly to a master switch, and then to the main bus. > > This is the first time I have seen a configuration like this > (without the contacter). What are the advantages, and disadvantages > of doing it this way? My maximum current draw is around 10A, so > well within the continuous current range of a small toggle switch. > > Thanks! > Justin > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=253209#253209 > > ________________________________ Message 31 ____________________________________ Time: 01:50:33 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: D.A.R question about fuse access At 11:39 AM 7/15/2009, you wrote: >I wonder how a DAR would look upon Vertical Power. No fuses. You >have a control box in the panel that you can reset a "failed" >circuit, but that's it. There's no ability to "change fuses in flight". . . . but you can 'reset' a tripped circuit under software control. One of the BIG arguments for breakers over fuses was the ease of resetting and low risk for dropping a fuse holder's cap . . . Emacs! . . . not to mention relief from having to carry spare fuses. The advantages are inarguable. Over the past 20+ years we've developed various tools for fault current protection including remotely controlled circuit breakers and sundry electronic fault detection and reaction systems. The Eclipse 500 had no breakers in the cockpit but pilots had access to LOTS of breakers via flat screens and software. But getting back to simple ideas: Fuses/breakers/other are intended to protect the airframe from hard faults that put other systems if not the entire airframe at risk. Once that fault occurs, the system is out of business. It's a good idea to make the event known to the crew . . . but resetting is 99.99% never useful or a good idea. It was reported that repeated resets of the cabin heater breaker on an airplane carrying Ricky Nelson may have figured in the fire that brought the airplane down. The prudent rule for tripped breakers and fuses (that are sized to avoid nuisance trips) is leave them alone until on the ground. Should it be that said breaker powers something you really need . . . then so much for failure tolerance (or perhaps even the decision to launch). From my personal sense of elegant solutions, the idea that replacing a perfectly good 25 cent fuse with hardware that is larger, more expensive, higher parts count, and perhaps driven by software does not make the airplane cost less, assemble faster or perform better . . . nor is it a positive return on investment. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 32 ____________________________________ Time: 01:55:10 PM PST US From: Phil Birkelbach Subject: Re: AeroElectric-List: D.A.R question about fuse access I can't reach any of my fuses in flight. I did this by design. I don't want to be tempted to fiddle with them. There isn't anything in my panel (VFR day/night) that will kill me if it fails, but fiddling with fuses when I should be flying the airplane can kill me. My DAR didn't ask. Some might. Just answer that there isn't any electrical circuit in your airplane that you can't LIVE without. If he/ she has a problem with that answer then make sure and warn your fellow builders about that DAR so that he/she may be avoided. Phil Birkelbach Houston RV7 - 727WB phil@petrasoft.net http://www.myrv7.com/ On Jul 15, 2009, at 2:19 PM, thomas sargent wrote: > > I'm confused by this thread. Are you telling me that the D.A.R. is > going to REQUIRE that my fuse block be accessible in flight? (Mine > isn't.) Or are you just telling me I need to have a rap prepared to > respond to the question. > > > -- > Tom Sargent > > ________________________________ Message 33 ____________________________________ Time: 02:14:48 PM PST US Subject: AeroElectric-List: Re: Contacter, or not? From: "heisan" The battery is mounted around 12" from the starter, and 20" from the panel. All 'heavy' current wires are fairly short. I really like the idea of making it as simple as possible. Added complexity just means extra failure points. I will definitely go for a fusible link and a switch. Thanks for the info. Justin Read this topic online here: http://forums.matronics.com/viewtopic.php?p=253233#253233 ________________________________ Message 34 ____________________________________ Time: 02:42:15 PM PST US Subject: RE: AeroElectric-List: D.A.R question about fuse access From: Tom, Absolutely not. You will find 100's of units with fuse blocks in very un-reachable positions. Do a little searching on Google. Remember, we are experimental - use poly fuses, fuse links or whatever you like. What folks are saying is that should any individual component be lost, be sure you can do without it (yes, Mr./Ms. DAR I can do without that). Period. Most prefer not trying to fix the broken thingy in flight, but rather get it down and tend to it on the ground. As Bob indicated failed items most often have nothing to do with the fuse/breaker. Stick and rudder folks know you really only need an airspeed indicator to get down safely in VFR. Make it a good one. Fuses are great and certainly reduce the owner's cost. I do like having breakers on my alternators to kill them if necessary. There again if the alternator breaker is popping for any reason than the occasional power surge, just leave it out and get down until fixed. Glenn From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Phil Birkelbach Sent: Wednesday, July 15, 2009 4:54 PM Subject: Re: AeroElectric-List: D.A.R question about fuse access I can't reach any of my fuses in flight. I did this by design. I don't want to be tempted to fiddle with them. There isn't anything in my panel (VFR day/night) that will kill me if it fails, but fiddling with fuses when I should be flying the airplane can kill me. My DAR didn't ask. Some might. Just answer that there isn't any electrical circuit in your airplane that you can't LIVE without. If he/she has a problem with that answer then make sure and warn your fellow builders about that DAR so that he/she may be avoided. Phil Birkelbach Houston RV7 - 727WB phil@petrasoft.net http://www.myrv7.com/ On Jul 15, 2009, at 2:19 PM, thomas sargent wrote: I'm confused by this thread. Are you telling me that the D.A.R. is going to REQUIRE that my fuse block be accessible in flight? (Mine isn't.) Or are you just telling me I need to have a rap prepared to respond to the question. -- Tom Sargent href="http://www.matronics.com/Navigator?AeroElectric-List">http://www. m atronics.com/Navigator?AeroElectric-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c o ntribution ________________________________ Message 35 ____________________________________ Time: 03:14:30 PM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Re: Automotive blade fuses? Good Evening Sarge, Do we really need fuses of that low an amperage? Seems to me that what we need to protect are the wires. Unless you have awfully small diameter wires, five amp should be as small as you need. Five amp will protect a number twenty-two wire. That is as small as I ever use! Happy Skies, Old Bob In a message dated 7/15/2009 2:42:17 P.M. Central Daylight Time, sarg314@gmail.com writes: Autozone has them, but only in values used commonly in cars. For your plane you will need a lot of small values - 1 or 2 or 3 amps. I doubt you'll find those at autozone or checker. B&C Specialty has them. **************Can love help you live longer? Find out now. (http://personals.aol.com/articles/2009/02/18/longer-lives-through-relationships/?ncid=emlweu slove00000001) ________________________________ Message 36 ____________________________________ Time: 03:41:40 PM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: D.A.R question about fuse access Good Evening Glenn, My primary instructor kept the airspeed covered up most of the time. I learned to control airspeed via the sound and by the feel of the controls. Who needs an airspeed indicator? I may not be able to hold it dead on a specific number, but I can sure stay fast enough to avoid a stall and slow enough to get it stopped in a reasonable distance! Happy Skies, Old Bob In a message dated 7/15/2009 4:43:18 P.M. Central Daylight Time, longg@pjm.com writes: Stick and rudder folks know you really only need an airspeed indicator to get down safely in VFR. Make it a good one. **************Can love help you live longer? Find out now. (http://personals.aol.com/articles/2009/02/18/longer-lives-through-relationships/?ncid=emlweu slove00000001) ________________________________ Message 37 ____________________________________ Time: 04:21:17 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Contacter, or not? At 02:42 PM 7/15/2009, you wrote: > >After all the great info and advice I got on the fuses, I thought I >would try asking about contacters too [Wink] . > >The aircraft manufacturer, and the engine manual both give a wiring >diagram that does NOT include a master contacter. The battery >positive goes directly to a master switch, and then to the main bus. > >This is the first time I have seen a configuration like this >(without the contacter). What are the advantages, and disadvantages >of doing it this way? My maximum current draw is around 10A, so >well within the continuous current range of a small toggle switch. The legacy design goal for a battery master disconnect is to provide a means by which nearly all wiring in the airplane is 'cold' when the disconnect is open. If the battery is conveniently located then some form of manual switch can be considered. Perhaps like this? Emacs! Emacs! The next reason for a battery master disconnect is to provide a means by which the battery can be shut off if the starter contactor (solenoid) sticks. If the battery master cannot positioned conveniently for manual operation, then perhaps a contactor is indicated. These can be low power devices like the EV series devices from TYCO . . . but it's pretty easy to make an el-cheeso contactor emulate the low power characteristics of the TYCO device. Finally, a couple of guys on the list were working on versions of remotely controlled, manual switches like this: http://aeroelectric.com/Catalog/AEC/9042/9042-100.pdf In any case, there's two good reasons for a battery master disconnect. The style is up to you as is the choice for installing one. Bob . . . --------------------------------------- ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) --------------------------------------- ________________________________ Message 38 ____________________________________ Time: 04:23:04 PM PST US Subject: Re: AeroElectric-List: Re: Automotive blade fuses? From: thomas sargent Well, yes, protecting the wire is the main task of the fuse. But If I have a device that I know should only use a fraction of an amp (my avionics cooling fan for example) and it starts drawing 2 amps, there's probably something seriously wrong with it. It will be toast long before the #22 wire (or a 5 amp fuse) ever burns up. The little thing could melt itself on 2 measly amps. So I put a 2 amp fuse on it. That still protects the wire and will keep the smoke level down in the cockpit. The fan is probably dead either way. On Wed, Jul 15, 2009 at 3:11 PM, wrote: > Good Evening Sarge, > > Do we really need fuses of that low an amperage? > > Seems to me that what we need to protect are the wires. Unless you have > awfully small diameter wires, five amp should be as small as you need. Five > amp will protect a number twenty-two wire. That is as small as I ever use! > > Happy Skies, > > Old Bob > > In a message dated 7/15/2009 2:42:17 P.M. Central Daylight Time, > sarg314@gmail.com writes: > > Autozone has them, but only in values used commonly in cars. For your > plane you will need a lot of small values - 1 or 2 or 3 amps. I doubt > you'll find those at autozone or checker. B&C Specialty has them. > > > ------------------------------ > > -- Tom Sargent ________________________________ Message 39 ____________________________________ Time: 04:52:28 PM PST US Subject: Re: AeroElectric-List: Contacter, or not? From: "Matt Prather" Bob, Your comments gave me another idea.. If you only have 12-14A to play with (little dynamo), and the airplane has a starter.. And your normal running power budget is a fairly high percentage of the output of the dynamo.. One could install a battery contactor (or starter relay) just for running the starter - in series with any starter/engine mounted relay/solenoid. Once the engine is running, the current draw from the monster contactor can be eliminated and you can drop back to a more power-frugal relay for driving the rest of the electronics on the airplane - a relay installed in parallel. I can't think of any downside. Regards, Matt- > At 02:42 PM 7/15/2009, you wrote: >> >> >>After all the great info and advice I got on the fuses, I thought I >>would try asking about contacters too [Wink] . >> >>The aircraft manufacturer, and the engine manual both give a wiring >>diagram that does NOT include a master contacter. The battery >>positive goes directly to a master switch, and then to the main bus. >> >>This is the first time I have seen a configuration like this >>(without the contacter). What are the advantages, and disadvantages >>of doing it this way? My maximum current draw is around 10A, so >>well within the continuous current range of a small toggle switch. > > The legacy design goal for a battery master > disconnect is to provide a means by which nearly > all wiring in the airplane is 'cold' when the > disconnect is open. If the battery is conveniently > located then some form of manual switch can be > considered. Perhaps like this? > > Emacs! > > Emacs! > > > The next reason for a battery master disconnect is > to provide a means by which the battery can be > shut off if the starter contactor (solenoid) > sticks. > > If the battery master cannot positioned conveniently > for manual operation, then perhaps a contactor is > indicated. These can be low power devices like the > EV series devices from TYCO . . . but it's pretty > easy to make an el-cheeso contactor emulate the > low power characteristics of the TYCO device. > > Finally, a couple of guys on the list were working > on versions of remotely controlled, manual switches > like this: > > http://aeroelectric.com/Catalog/AEC/9042/9042-100.pdf > > In any case, there's two good reasons for a battery > master disconnect. The style is up to you as is > the choice for installing one. > > > Bob . . . > > --------------------------------------- > ( . . . a long habit of not thinking ) > ( a thing wrong, gives it a superficial ) > ( appearance of being right . . . ) > ( ) > ( -Thomas Paine 1776- ) > --------------------------------------- > > ________________________________ Message 40 ____________________________________ Time: 07:23:49 PM PST US From: "Rick and Sandra Lark" Subject: AeroElectric-List: glass fuses That is really what you should be using (is ATO blade type fuses) over the >glass fuses. From our experience, using glass fuses has many negatives and >they aren't something we'd really recommend for airplanes anymore. Bob> Absolutely! These have fragile internal connections at the ends of the fusible links . . . they also used large area, low pressure connections in their holders. Not gas-tight. Hi all: 1st time posting to this list. Years ago I owned a "75 Celica GT that had an electric fuel pump. The car kept quitting for no apparent reason (usually when my girlfriend drove it). Ended up my favorite auto mechanic found the fuse end cap was loose that fed the fuel pump. There is no way I would use glass fuses for anything in an aircraft. Regards Rick Lark Southampton, Ont RV10 #40956 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.