---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 10/31/18: 13 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:11 AM - Re: Re: IVOprop current limiter project (Robert L. Nuckolls, III) 2. 08:23 AM - Re: Re: IVOprop current limiter project (Robert L. Nuckolls, III) 3. 09:41 AM - Question on Grounding (Rocketman1988) 4. 11:01 AM - Re: Question on Grounding (Robert L. Nuckolls, III) 5. 12:32 PM - Re: Question on Grounding (Rocketman1988) 6. 05:09 PM - Re: Question on Grounding (FLYaDIVE) 7. 05:36 PM - E-Bus Fuse Size (user9253) 8. 06:13 PM - Re: Question on Grounding (iiNet) 9. 06:32 PM - Re: Question on Grounding (Charlie England) 10. 07:10 PM - Re: Question on Grounding (Kelly McMullen) 11. 07:39 PM - Re: Question on Grounding (user9253) 12. 07:51 PM - Re: Re: Question on Grounding (Earl Schroeder) 13. 08:23 PM - Re: Question on Grounding (John B) ________________________________ Message 1 _____________________________________ Time: 08:11:20 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: IVOprop current limiter project At 01:11 PM 10/30/2018, you wrote: > >Good job Bob Nuckolls and Todd Bartrim and Paul Fisher. Thank you. This is a good example of what has been described as 'spontaneous organization', 'the invisible hand', 'division of labor', and countless other phrases for centuries. Simply put, individuals with time, talents and resources to move a particular activity forward steps up to the task and gets 'er done. The whole is at-risk until all the bits an pieces are in place irrespective of size and difficulty. Every contribution is of paramount importance. I am pleased to have been a participant in this enhancement to the state of science and art of our craft. I'll get the drawings updated. I'd be pleased to post the data package in the DIY archives on aeroelectric.com Bob . . . ________________________________ Message 2 _____________________________________ Time: 08:23:59 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: IVOprop current limiter project At 02:49 PM 10/30/2018, you wrote: > >Todd, >Thanks for the explanation. You are right about the Gerber >files. The other 7 files have pictures. I missed the Gerber file >folder because I was looking for a picture. My bad. I have now >downloaded the Gerber files. > I use "Eagle" for making schematics and boards and generating > Gerber files. Unfortunately it is not intuitive or user friendly > unless used frequently. If I do not use the program for a long > time, I have to relearn it. There have been threads in the past on > this forum discussing other easier to use software. There are several offerings out there. My particular fav is ExpressPCB whiche does have a schematic capture and bill of materials utility. Having 'cut my teeth' on the schematic styles of the now century old ARRL/QST publications, I've never warmed up to the schematic/net-list features of ExpressPCB. My artwork layout skills have roots in punched out donuts and rolls of black, red or blue tape on 1/10th grid mylar. So I was pleased that ExpressPCB was particularly friendly to a layout artist suffering from what might be considered arcane habits. ExpressPCB has excellent prototyping services with 3-5 day turnaround . . . saved my arse numerous times over the past 20 years. You DO have to order one set of prototypes before you can pay an extra fee for Gerber files. No big deal since you probably want to stuff at least one proof of concept board before you order up a batch of production. Further, like the AutoCAD symbols library I've posted to aeroelectric.com, I have a library of custom ExpressPCB components I can put up on the server for anyone who's interested. Bob . . . ________________________________ Message 3 _____________________________________ Time: 09:41:14 AM PST US Subject: AeroElectric-List: Question on Grounding From: "Rocketman1988" I have an RV-10 that has a dedicated ground cable running from the aft battery to the firewall. This cable is connected to the firewall/panel (airframe) ground AND is connected near the battery, to the airframe. My question is: Would it be better to remove the cable in the aft near the battery and have only one connection to the airframe, the one at the firewall/panel? Or is it ok to have two points of contact, one forward and one aft? Read this topic online here: http://forums.matronics.com/viewtopic.php?p=484119#484119 ________________________________ Message 4 _____________________________________ Time: 11:01:30 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Question on Grounding At 11:40 AM 10/31/2018, you wrote: > > >I have an RV-10 that has a dedicated ground cable running from the >aft battery to the firewall. This cable is connected to the >firewall/panel (airframe) ground AND is connected near the battery, >to the airframe. > >My question is: > >Would it be better to remove the cable in the aft near the battery >and have only one connection to the airframe, the one at the firewall/panel? > >Or is it ok to have two points of contact, one forward and one aft? Resistance in the wire is higher than thru the airframe . . . the only thing it adds is weight. But it doesn't hurt anything from an electrical perspective. Bob . . . ________________________________ Message 5 _____________________________________ Time: 12:32:10 PM PST US Subject: AeroElectric-List: Re: Question on Grounding From: "Rocketman1988" Thanks, Bob. I will just leave both attached... Read this topic online here: http://forums.matronics.com/viewtopic.php?p=484123#484123 ________________________________ Message 6 _____________________________________ Time: 05:09:39 PM PST US From: FLYaDIVE Subject: Re: AeroElectric-List: Question on Grounding BOB! Are you on DRUGS! I got to here your explanation on this one! You are really saying that the resistance through the air frame is LESS than that of a singe run of COPPER wire? WIRE HELL! It's CABLE, what, a #2 AWG. AHhhhh let me guess??? You are thinking that just because there is more surface area, the resistance will be lower? This is DC not RF! Well, ZERO is always ZERO. And the shortest Zero between two points wins. That would be the Cable. What about all the lap joints? Add some time to lap joints and you have a failure mode. Maybe not much resistance, but even 1 mo is more than a cable. And when you really consider it... Since the CABLE is run in parallel with the air frame. BOTH paths are winners. Sure it adds weight. But I will gladly add weight and eliminate all those possible failure points. Gee, isn't it Piper that tried using ONLY the air frame as a ground and had all types of failures, not only to the wiring but to the starter as well, as it was drawing excessive current and had a higher current draw? And then they got smart and started worrying about WEIGHT. So they went to ALUMINUM Cables. SMART! Like dropping a brick on your foot, smart! Those engineers must have gone to the same school as the engineers that used aluminum wire for house wiring... Remember those house fires? Which lead to higher insurance rates. Aluminum, which led to an AD on their planes, an AD to replace the aluminum wire with Copper. Totally Shocked, Barry On Wed, Oct 31, 2018 at 2:09 PM Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 11:40 AM 10/31/2018, you wrote: > > Rocketman@etczone.com> > > I have an RV-10 that has a dedicated ground cable running from the aft > battery to the firewall. This cable is connected to the firewall/panel > (airframe) ground AND is connected near the battery, to the airframe. > > My question is: > > Would it be better to remove the cable in the aft near the battery and > have only one connection to the airframe, the one at the firewall/panel? > > Or is it ok to have two points of contact, one forward and one aft? > > > Resistance in the wire is higher than > thru the airframe . . . the only thing > it adds is weight. But it doesn't hurt > anything from an electrical perspective. > > > Bob . . . > ________________________________ Message 7 _____________________________________ Time: 05:36:03 PM PST US Subject: AeroElectric-List: E-Bus Fuse Size From: "user9253" A pilot recently experienced an instrument panel blackout at night. When he turned on the E-Bus switch, the panel briefly came back on, but soon went black again. Luckily the weather was good and he landed safely. You can read about it here. http://www.vansairforce.com/community/showthread.php?t=165520 The E-Bus was protected by 15 amp fuses. Evidently the second and third owners of the aircraft connected more loads to the E-Ebus, eventually overloading it. If two fuses are connected in series, even if one is bigger, either one or both could blow in case of hard ground fault. Should the E-Bus have main fuses? If so, then how much larger should the main fuse be than a branch circuit fuse? -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=484131#484131 ________________________________ Message 8 _____________________________________ Time: 06:13:12 PM PST US Subject: Re: AeroElectric-List: Question on Grounding From: iiNet Sorry, far more shocked by your comments Barry. #2 AWG is only required for start currents and is overkill for relatively l ow current in-flight loads. There is already a big #2 AWG wire for positive t o the starter motor and having another one for ground is simply unnecessary. As they say, worry about the grams added to the aeroplane and let the kilog rams take care of themselves. Yes, arcing between the stands of ally wire caused fires, which is why Eric J ones at Perihelion Design sells copper-clad (extruded) wire to stop oxidatio n and varying potential between strands. So, choose copper (heavy) or copper -clad ally (larger diameter but 45% lighter), but there is no need to add a g round wire for normal inflight loads that are very easily serviced by an all y airframe. An extra big wire does little to improve start performance (if the wiring ha s gas tight connections to the airframe, which would also apply to any extra wire connected in parallel), so it adds nothing but unnecessary weight. The argument for separate power and ground wires and a forest of common ground t abs for smaller electrical items it=99s is a totally different story. Kind regards, Stu Sent from my iPhone > On 1 Nov 2018, at 11:08, FLYaDIVE wrote: > > BOB! > > Are you on DRUGS! > > I got to here your explanation on this one! > > You are really saying that the resistance through the air frame is LESS th an that of a singe run of COPPER wire? > WIRE HELL! It's CABLE, what, a #2 AWG. > AHhhhh let me guess??? You are thinking that just because there is more s urface area, the resistance will be lower? > This is DC not RF! > Well, ZERO is always ZERO. And the shortest Zero between two points wins. > That would be the Cable. > What about all the lap joints? Add some time to lap joints and you have a failure mode. Maybe not much resistance, but even 1 mo is more than a cabl e. > And when you really consider it... Since the CABLE is run in parallel wit h the air frame. BOTH paths are winners. > > Sure it adds weight. But I will gladly add weight and eliminate all those possible failure points. > Gee, isn't it Piper that tried using ONLY the air frame as a ground and ha d all types of failures, not only to the wiring but to the starter as well, a s it was drawing excessive current and had a higher current draw? > And then they got smart and started worrying about WEIGHT. So they went t o ALUMINUM Cables. SMART! Like dropping a brick on your foot, smart! Thos e engineers must have gone to the same school as the engineers that used alu minum wire for house wiring... Remember those house fires? Which lead to h igher insurance rates. Aluminum, which led to an AD on their planes, an AD t o replace the aluminum wire with Copper. > > Totally Shocked, > Barry > >> On Wed, Oct 31, 2018 at 2:09 PM Robert L. Nuckolls, III wrote: >> At 11:40 AM 10/31/2018, you wrote: one.com> >>> >>> I have an RV-10 that has a dedicated ground cable running from the aft b attery to the firewall. This cable is connected to the firewall/panel (airf rame) ground AND is connected near the battery, to the airframe. >>> >>> My question is: >>> >>> Would it be better to remove the cable in the aft near the battery and h ave only one connection to the airframe, the one at the firewall/panel? >>> >>> Or is it ok to have two points of contact, one forward and one aft? >> >> Resistance in the wire is higher than >> thru the airframe . . . the only thing >> it adds is weight. But it doesn't hurt >> anything from an electrical perspective. >> >> >> Bob . . . ________________________________ Message 9 _____________________________________ Time: 06:32:28 PM PST US Subject: Re: AeroElectric-List: Question on Grounding From: Charlie England Hi Barry, If you squeeze that aluminum airframe into an air-free cylinder, what gauge wire would be the same diameter? #0? #000? #0000000000? Give it some thought. And if you think aluminum is a bad choice for an electrical conductor, you might want to move out of your house. (Check the triplex coming from the pole to the meter base. Might be worth checking the run from the meter to your panel, too.) Oh, you might want to stay away from any structure that uses power off the grid, too. (See those high tension lines running across the country?) Aluminum got that bad rap due to improper mix of wire type & connector type. Look at the cheap wall switches & outlets that use the spring terminals in back for wire; they are marked for only copper. But if you look at the higher quality screw terminal versions, many (most?) are marked AL/CU; certified for either copper or aluminum wire. Guess which got used back in the day when aluminum got that bad rap. Charlie On 10/31/2018 7:08 PM, FLYaDIVE wrote: > BOB! > > Are you on DRUGS! > > I got to here your explanation on this one! > > You are really saying that the resistance through the air frame is > LESS than that of a singe run of COPPER wire? > WIRE HELL! It's CABLE, what, a #2 AWG. > AHhhhh let me guess??? You are thinking that just because there is > more surface area, the resistance will be lower? > This is DC not RF! > Well, ZERO is always ZERO. And the shortest Zero between two points wins. > That would be the Cable. > What about all the lap joints? Add some time to lap joints and you > have a failure mode. Maybe not much resistance, but even 1 mo is more > than a cable. > And when you really consider it... Since the CABLE is run in parallel > with the air frame. BOTH paths are winners. > > Sure it adds weight. But I will gladly add weight and eliminate all > those possible failure points. > Gee, isn't it Piper that tried using ONLY the air frame as a ground > and had all types of failures, not only to the wiring but to the > starter as well, as it was drawing excessive current and had a higher > current draw? > And then they got smart and started worrying about WEIGHT. So they > went to ALUMINUM Cables. SMART! Like dropping a brick on your foot, > smart! Those engineers must have gone to the same school as the > engineers that used aluminum wire for house wiring... Remember those > house fires? Which lead to higher insurance rates. Aluminum, which > led to an AD on their planes, an AD to replace the aluminum wire with > Copper. > > Totally Shocked, > Barry > > On Wed, Oct 31, 2018 at 2:09 PM Robert L. Nuckolls, III > > > wrote: > > At 11:40 AM 10/31/2018, you wrote: >> > >> >> I have an RV-10 that has a dedicated ground cable running from >> the aft battery to the firewall. This cable is connected to the >> firewall/panel (airframe) ground AND is connected near the >> battery, to the airframe. >> >> My question is: >> >> Would it be better to remove the cable in the aft near the >> battery and have only one connection to the airframe, the one at >> the firewall/panel? >> >> Or is it ok to have two points of contact, one forward and one aft? > > Resistance in the wire is higher than > thru the airframe . . . the only thing > it adds is weight. But it doesn't hurt > anything from an electrical perspective. > > > Bob . . . > --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 10 ____________________________________ Time: 07:10:14 PM PST US Subject: Re: AeroElectric-List: Question on Grounding From: Kelly McMullen Sorry Barry, If anyone is on drugs it is you. I don't know of any TC aircraft that does not use the aluminum skin or steel tube frame for the ground path. Take Mooney for instance. The battery(ies) location is behind the baggage compartment. Forward of the baggage compartment the airframe is steel tubes, with aluminum covering attached with #4 sheet metal screws. The ground path is battery to the aluminum monocoque where it is mounted, connected to that steel tube frame, connected to the stainless firewall. Cessna mounted the battery where needed for W&B, grounded to the aluminum airframe. Vans has a pretty good reputation for experimental kits. Their wiring diagram shows battery grounded to the airframe. Of course the builder can deviate if they wish. Piper's problems were aluminum CABLES and connectors, not the airframe or method of grounding. Kelly On 10/31/2018 5:08 PM, FLYaDIVE wrote: > BOB! > > Are you on DRUGS! > > ________________________________ Message 11 ____________________________________ Time: 07:39:28 PM PST US Subject: AeroElectric-List: Re: Question on Grounding From: "user9253" I agree with Bob -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=484136#484136 ________________________________ Message 12 ____________________________________ Time: 07:51:26 PM PST US Subject: Re: AeroElectric-List: Re: Question on Grounding From: Earl Schroeder Me too > On Oct 31, 2018, at 9:38 PM, user9253 wrote: > > > I agree with Bob > > -------- > Joe Gores > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=484136#484136 > > > > > > > > > ________________________________ Message 13 ____________________________________ Time: 08:23:53 PM PST US From: John B Subject: Re: AeroElectric-List: Question on Grounding Bob is correct. The airframe makes the ground wire superfluous. This assumes that no corrosion develops between the fasteners and the various fuselage skins and parts. After two or three decades, corrosion developed in the airframes, and a formal ground wire, of copper, became necessary for consistent engine starting. On a new RV-type aircraft, that heavy #2 wire is just getting a free ride. It is unnecessary, electrically, UNTIL the airframe corrodes to the point that excessive resistance is developed. IF it corrodes at all. Modern epoxy primers and finishes may prevent corrosion. That 50-year-old Piper sitting on the ramp in the rain likely corroded quite quickly, and became one of those airplanes that was "hard to start," and had other electrical problems, almost always caused by an inconsistent ground. Technically, Bob is right. Again. Many words were devoted to this very subject in the Aeroelectric Connection book. John B On Wed, Oct 31, 2018 at 7:14 PM FLYaDIVE wrote: > BOB! > > Are you on DRUGS! > > I got to here your explanation on this one! > > You are really saying that the resistance through the air frame is LESS > than that of a singe run of COPPER wire? > WIRE HELL! It's CABLE, what, a #2 AWG. > AHhhhh let me guess??? You are thinking that just because there is more > surface area, the resistance will be lower? > This is DC not RF! > Well, ZERO is always ZERO. And the shortest Zero between two points wins. > That would be the Cable. > What about all the lap joints? Add some time to lap joints and you have a > failure mode. Maybe not much resistance, but even 1 mo is more than a > cable. > And when you really consider it... Since the CABLE is run in parallel > with the air frame. BOTH paths are winners. > > Sure it adds weight. But I will gladly add weight and eliminate all those > possible failure points. > Gee, isn't it Piper that tried using ONLY the air frame as a ground and > had all types of failures, not only to the wiring but to the starter as > well, as it was drawing excessive current and had a higher current draw? > And then they got smart and started worrying about WEIGHT. So they went > to ALUMINUM Cables. SMART! Like dropping a brick on your foot, smart! > Those engineers must have gone to the same school as the engineers that > used aluminum wire for house wiring... Remember those house fires? Which > lead to higher insurance rates. Aluminum, which led to an AD on their > planes, an AD to replace the aluminum wire with Copper. > > Totally Shocked, > Barry > > On Wed, Oct 31, 2018 at 2:09 PM Robert L. Nuckolls, III < > nuckolls.bob@aeroelectric.com> wrote: > >> At 11:40 AM 10/31/2018, you wrote: >> >> Rocketman@etczone.com> >> >> I have an RV-10 that has a dedicated ground cable running from the aft >> battery to the firewall. This cable is connected to the firewall/panel >> (airframe) ground AND is connected near the battery, to the airframe. >> >> My question is: >> >> Would it be better to remove the cable in the aft near the battery and >> have only one connection to the airframe, the one at the firewall/panel? >> >> Or is it ok to have two points of contact, one forward and one aft? >> >> >> Resistance in the wire is higher than >> thru the airframe . . . the only thing >> it adds is weight. But it doesn't hurt >> anything from an electrical perspective. >> >> >> Bob . . . >> > ------------------------------------------------------------------------------------- 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.