---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 04/14/07: 19 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:28 AM - Should 22K uF capacitor be fused? () 2. 03:50 AM - Re: Z-16 (Rodney Dunham) 3. 08:35 AM - curious questions (Michael T. Ice) 4. 08:54 AM - Crimp on terminals (Grant Neilson) 5. 09:57 AM - Re: Relay and capacitor info needed (Robert L. Nuckolls, III) 6. 09:58 AM - Re: Should 22K uF capacitor be fused? (Robert L. Nuckolls, III) 7. 10:04 AM - Z-11 (Gaye and Vaughn) 8. 10:05 AM - Re: Crimp on terminals (Ron Quillin) 9. 10:06 AM - Re: Z-16 (Robert L. Nuckolls, III) 10. 11:29 AM - Z-16-not Z-11 (Gaye and Vaughn) 11. 01:17 PM - Battery insulation (Leo Holler) 12. 01:38 PM - Re: Battery insulation (BobsV35B@aol.com) 13. 01:55 PM - Re: Relay and capacitor info needed () 14. 05:01 PM - Re: Crimp on terminals (Larry Mac Donald) 15. 05:40 PM - Re: curious questions (Larry Mac Donald) 16. 05:52 PM - Alternator (Rino Lacombe) 17. 06:11 PM - Re: Battery insulation (Leo Holler) 18. 07:06 PM - Re: Re: Battery insulation (BobsV35B@aol.com) 19. 07:37 PM - Re: Battery insulation (Jim Jewell) ________________________________ Message 1 _____________________________________ Time: 12:28:02 AM PST US Subject: AeroElectric-List: Should 22K uF capacitor be fused? From: Hello Bob I was reading a post you made from 01-2000 about putting a 10 amp fuse on the 22k uF capacitor of a Rotax internal generator. Do you still advocate fusing the capacitor? I plan on using a 22K uF 35V with a 105C rating. Thx. Ron Parigoris Below is some of 2000 post you made: The general rull of thumb for 60 Hz power supplies is 1,000 uFd per amp of power supply capacity. Applying the same rule to the 18A Rotax alternator puts the 22,000 uFd device right in the ballpark. The capacitor does it's job by looking as if it were a dead short to the AC voltages on the system. ANY device connected in series with the capacitor raises it's equivalent series resistance value and degrades it's ability to do the job. A 10A fuse is a good idea . . . capacitors rarely short but it's not impossible. Better to open a fuse that blow the end out of the capacitor . . . they stink and are really messy. Capacitors rated for operation at 85 degrees C are standard. Further, they don't have to be big either. A 33,000 uFd, 16 volt device can be had with an envelope of 1.4" diameter and 2.13" long. You want a computer grade device with 10-32 screw terminals. These have the lowest internal resistance and are most suited for attaching the fat wires used to wire the alternator system. ________________________________ Message 2 _____________________________________ Time: 03:50:49 AM PST US From: "Rodney Dunham" Subject: Re: AeroElectric-List: Z-16 Bob said... "It's unlikely that anyone on staff at your supplier can discuss applications and options with any logic. They're only parroting information fed to them by others who are equally un-informed as to how you meet your design goals." How right you are! I called Jabiru USA to ask about the voltage regulator they sell and install on their Jabiru engines and aircraft. They could not tell me any more about the regulator than "It's solid state." They also didn't seem to understand the physics of the PM Dynamo in their engines. After looking at their wiring in the few planes under construction, I concluded they could use a 'Connection Seminar! But, I kept my mouth shut. I was there to learn from them. And it was a good seminar in all other respects. Rod _________________________________________________________________ Download Messenger. Join the im Initiative. Help make a difference today. http://im.live.com/messenger/im/home/?source=TAGHM_APR07 ________________________________ Message 3 _____________________________________ Time: 08:35:17 AM PST US From: "Michael T. Ice" Subject: AeroElectric-List: curious questions Hello, A friend of mine that occasionally helps me work on my RV-9 has asked me some questions that I can't answer satisfactorily. He is a great guy and has a very curious mind, he owns and works on boats, cars, etc, but doesn't have a history with aircraft. These are the questions in his own words posted below. Any help will be gratefully accepted. In the course of helping a friend construct an RV 9 I had the opportunity to examine the electrical system design. I was puzzled at the use of a master relay (solenoid) to switch the entire electrical system. A number of questions occurred to me regarding this design: The questions: How much amperage draw does the solenoid consume simply being energized? At what voltage does the Solenoid release? And why this design? It seems to me inserting the master relay (solenoid) into the electrical system has no benefit and some detriment. The detriments are: 1. constant draw on battery when energized. 2. greater complexity. 3. increased weight (all 6 oz of the solenoid) 4. failure of the complete electrical system if a) the solenoid fails, or b) if you have alternator failure and voltage drops low enough to allow the solenoid to not close/open (we have all heard the clicking of the starter solenoid on a run down car battery- but the radios still work). Contrast this with the benefit- uh- what benefit? There is the same amount of current flowing to the panel from the battery whether it comes via the relay or via a straight run to a master switch. Starter current continues to utilize the starter solenoid. Alternator output current can be routed directly to the battery since the field voltage can be turned off via the master switch (and as I understand the design, inserting a fuse in the alternator output line). My limited knowledge may be impeding my appreciation of the function of the master relay- but I have been pondering this- and can't come up with a good rationale. On large aircraft, where you have significant electrical loads that are distant from the cockpit, it would make sense to use a relay so that you minimize voltage drop and/or weight by eliminating long wiring runs. But this doesn't seem to be the case here. The argument regarding electromagnetic fields near radios does not hold up since the loads are the same whether switched through a relay or not. I guess the bottom line is- There are some VERY smart people building these aircraft. Surely there is a good reason for the master relay design- I just want to know what it is? In the course of helping a friend construct an RV 9 I had the opportunity to examine the electrical system design. I was puzzled at the use of a master relay (solenoid) to switch the entire electrical system. A number of questions occurred to me regarding this design: The questions: How much amperage draw does the solenoid consume simply being energized? At what voltage does the Solenoid release? And why this design? It seems to me inserting the master relay (solenoid) into the electrical system has no benefit and some detriment. The detriments are: 1. constant draw on battery when energized. 2. greater complexity. 3. increased weight (all 6oz of the solenoid) 4. failure of the complete electrical system if a) the solenoid fails, or b) if you have alternator failure and voltage drops low enough to allow the solenoid to not close/open (we have all heard the clicking of the starter solenoid on a run down car battery- but the radios still work). Contrast this with the benefit- uh- what benefit? There is the same amount of current flowing to the panel from the battery whether it comes via the relay or via a straight run to a master switch. Starter current continues to utilize the starter solenoid. Alternator output current can be routed directly to the battery since the field voltage can be turned off via the master switch (and as I understand the design, inserting a fuse in the alternator output line). My limited knowledge may be impeding my appreciation of the function of the master relay- but I have been pondering this- and can't come up with a good rationale. On large aircraft, where you have significant electrical loads that are distant from the cockpit, it would make sense to use a relay so that you minimize voltage drop and/or weight by eliminating long wiring runs. But this doesn't seem to be the case here. The argument regarding electromagnetic fields near radios does not hold up since the loads are the same whether switched through a relay or not. I guess the bottom line is- There are some VERY smart people building these aircraft. Surely there is a good reason for the master relay design- I just want to know what it is? Blue Skies, Mike Ice RV-9, electrical almost complete, just laid up fiberglass skirts for the canopy last night, next up: motor mount, install gear legs, then engine ________________________________ Message 4 _____________________________________ Time: 08:54:08 AM PST US From: "Grant Neilson" Subject: AeroElectric-List: Crimp on terminals Is it a good idea to "tin" wire ends with a little solder before using crimp on terminals for D miniature connectors, or not? Grant Neilson RV9A, finishing ________________________________ Message 5 _____________________________________ Time: 09:57:17 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Relay and capacitor info needed At 06:36 AM 4/14/2007 +0000, you wrote: > >Have a few questions (4) about relays and capacitors to be used on my 914 >Rotax powered Europa: > >1) If I use a B+C S704-1 "Sealed" relay for OVP to open and close a yellow >output wire of the internal generator (mounted on engine side of >firewall), are the chances good it will not blow apart if I choose to wave >soar up to 35K with long wings? How about at 18K with intercooled motor >running hard and temp of relay gets up to 212F? Use the relay to do AC switching instead of DC switching . . . >2) If I use a Bosh 75 amp "Vented" SPST relay #75251 from >www.waytekwire.com on the engine side of the firewall used in parallel >with the B+C for OVP to disconnect the 22K uF capacitor from my E-Bus. >Should the service life be reasonable on a vented relay on the engine side >of the firewall on an airplane stored for the most part in a unheated tin >hangar? It has a small slit to allow it to vent. (On my design, if >capacitor shorted it would draw down the E-Bus with no way to sever short >without 2nd relay. My design addresses failure of battery (opened or dead) >when attempting in flight restart after soaring) Why not wire your PM alternator like Z-16 and leave the capacitor across the battery all the time? >3) When turning on and off the internal generator, the 75 amp Bosh relay >will be used to charge up the 22K uF capacitor. Can this relay most like >give good service charging up the capacitor at least once per flight? >Could the B+C S704-1 "Sealed" relay most like take the abuse of charging >up the capacitor at least once per flight and be used in place of the Bosh >75 amp? (Bosh weighs in at 3.1 oz and has dual contacts) If you're wired per the latest control philosophies for PM alternators, the capacitor charges through the battery contactor which won't be particularly stressed by this activity. The act of charging the capacitor using the output of the alternator is current limited by the alternator's dynamics. No inrush concerns here. >4) I want to use for pitch trim small "Sealed" Osram 12v 5a relays from >Digikey pn G6B 2214P US DC12, are the chances good it will not blow apart >if I choose to wave soar up to 35K with long wings? Will be mounted in >cockpit. What kind of trim motors? You're probably fine with MAC/RayAllen actuators. You could easily go all solid state with these duties and eliminate the worries entirely. You're not going to "blow them apart" . . . the risk is that at reduced pressures, the arcing that inevitably forms between spreading contacts is more severe and you get reduced service life. I've not tested open relays at these altitudes . . . our mil-spec products are sealed. Bob . . . ---------------------------------------- ( IF one aspires to be "world class", ) ( what ever you do must be exercised ) ( EVERY day . . . ) ( R. L. Nuckolls III ) ---------------------------------------- ________________________________ Message 6 _____________________________________ Time: 09:58:54 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Should 22K uF capacitor be fused? At 07:15 AM 4/14/2007 +0000, you wrote: > >Hello Bob > >I was reading a post you made from 01-2000 about putting a 10 amp fuse on >the 22k uF capacitor of a Rotax internal generator. > >Do you still advocate fusing the capacitor? I plan on using a 22K uF 35V >with a 105C rating.' It doesn't hurt but it's also unlikely to be a big help either. The fault currents that can flow in a self destructing capacitor can stay below fuse blowing levels. Better to treat this capacitor as an expendable like batteries and tires. Replace it every so often, probably 3-4 years is fine. Even then, you're sandbagging a really rare event. Bob . . . ________________________________ Message 7 _____________________________________ Time: 10:04:20 AM PST US From: "Gaye and Vaughn" Subject: AeroElectric-List: Z-11 have attempted to incorporate the new rev 11 rotax alternator system into my dual alt system, as Mike Gregory suggested. PDF file attached. I have also incorporated several changes made by list members because they made too much sense to ignore. BOB, does this give me security in the air. Thank you all. Vaughn Teegarden Europa XS mono, Rotax 914 ________________________________ Message 8 _____________________________________ Time: 10:05:16 AM PST US Subject: Re: AeroElectric-List: Crimp on terminals From: Ron Quillin At 08:53 4/14/2007, you wrote: > > >Is it a good idea to "tin" wire ends with a little solder before using crimp >on terminals for D miniature connectors, or not? Not only is it not a good idea, it's not even permitted when doing qualified assembly for JPL/NASA flight equipment. This does assume proper crimp equipment. Ron Q. >Grant Neilson >RV9A, finishing ________________________________ Message 9 _____________________________________ Time: 10:06:31 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Z-16 At 06:49 AM 4/14/2007 -0400, you wrote: > > >Bob said... > >"It's unlikely that anyone on staff at your supplier can discuss >applications and options with any logic. They're only parroting >information fed to them by others who are equally un-informed as to how >you meet your design goals." > >How right you are! I called Jabiru USA to ask about the voltage regulator >they sell and install on their Jabiru engines and aircraft. They could not >tell me any more about the regulator than "It's solid state." They also >didn't seem to understand the physics of the PM Dynamo in their engines. It's difficult for folks who WORK in this environment. I just got home from delivering a Sandbox session to engineering professionals from my place of work. Wichita State lets me use a really nice classroom in the NIAR building for Saturday morning classes. These are folks who do not get an opportunity to exercise the best they know how to do every day and it gets away from you. We did a refresher course this morning on DC motor characteristics that was well received. My chief scientist gives me feedback on these efforts and he has enthusiastically supported and attended the classes since day-one. >After looking at their wiring in the few planes under construction, I >concluded they could use a 'Connection Seminar! But, I kept my mouth shut. >I was there to learn from them. And it was a good seminar in all other >respects. It easy to blow off any need for knowing more about things that you don't understand or are not interested in. If I were selling that hardware, I have it apart and certainly have schematics to refer to. It may not be mortal sin to sell stuff you don't understand and cannot explain . . . but it's not a venial sin either. Bob . . . ---------------------------------------- ( IF one aspires to be "world class", ) ( what ever you do must be exercised ) ( EVERY day . . . ) ( R. L. Nuckolls III ) ---------------------------------------- ________________________________ Message 10 ____________________________________ Time: 11:29:26 AM PST US From: "Gaye and Vaughn" Subject: AeroElectric-List: Z-16-not Z-11 Hi all you people who prabably have functioning brain cells left. Here is my message again with the proper heading. It seems that I can't destinguish between "Z" and "Rev". I have attempted to incorporate the new rev 11 rotax alternator system into my dual alt system, as Mike Gregory suggested. PDF file attached. I have also incorporated several changes made by list members because they made too much sense to ignore. BOB, does this give me security in the air. Thank you all. Vaughn Teegarden Europa XS mono, Rotax 914 ________________________________ Message 11 ____________________________________ Time: 01:17:52 PM PST US Subject: AeroElectric-List: Battery insulation From: "Leo Holler" A friend has a Cherokee 140 with an original battery box beneath the rear seat. He has replaced the lead acid battery with a 16 AH RG battery. The RG battery is oriented the same as the lead acid battery had been. To keep the new battery from flopping around (it is much smaller than the old lead acid one) he inserted DOW HI (blue board foam) insulation around the four sides. I don't recall seeing any insulation under or over the battery. My question: Is this insulation OK or is there a chance that the battery could overheat if under heavy recharge? The installation looks nice and tidy and is very lightweight, but I'd like to make sure he is not set up for a problem in flight. Please comment if you can. Leo Holler leoh@gci.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=106925#106925 ________________________________ Message 12 ____________________________________ Time: 01:38:04 PM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Battery insulation Good Afternoon Leo, Is the RG battery he is using in his Cherokee listed as being approved for that use? Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Air Park LL22 Downers Grove, IL 60516 630 985-8503 In a message dated 4/14/2007 3:20:30 P.M. Central Daylight Time, leoh@gci.net writes: A friend has a Cherokee 140 with an original battery box beneath the rear seat. He has replaced the lead acid battery with a 16 AH RG battery. The RG battery is oriented the same as the lead acid battery had been. To keep the new battery from flopping around (it is much smaller than the old lead acid one) he inserted DOW HI (blue board foam) insulation around the four sides. I don't recall seeing any insulation under or over the battery. My question: Is this insulation OK or is there a chance that the battery could overheat if under heavy recharge? The installation looks nice and tidy and is very lightweight, but I'd like to make sure he is not set up for a problem in flight. Please comment if you can. Leo Holler ************************************** See what's free at http://www.aol.com. ________________________________ Message 13 ____________________________________ Time: 01:55:28 PM PST US Subject: Re: AeroElectric-List: Relay and capacitor info needed From: Hello Bob Thx. for the reply. There remains unanswered questions if you don't mind, I will note below with **** >>Have a few questions (4) about relays and capacitors to be used on my 914 >>Rotax powered Europa: >> >>1) If I use a B+C S704-1 "Sealed" relay for OVP to open and close a yellow >>output wire of the internal generator (mounted on engine side of >>firewall), are the chances good it will not blow apart if I choose to wave >>soar up to 35K with long wings? How about at 18K with intercooled motor >>running hard and temp of relay gets up to 212F? > > Use the relay to do AC switching instead of DC switching . . . **** The yellow output wire of the Rotax generator is AC. My question has to do with the internal pressure of the relay blowing apart the sealed container like a bag of potato chips that will explode at altitude. Do you think this relay can take the internal pressure of 35K or 18K at 212F without exploding? >>2) If I use a Bosh 75 amp "Vented" SPST relay #75251 from >>www.waytekwire.com on the engine side of the firewall used in parallel >>with the B+C for OVP to disconnect the 22K uF capacitor from my E-Bus. >>Should the service life be reasonable on a vented relay on the engine side >>of the firewall on an airplane stored for the most part in a unheated tin >>hangar? It has a small slit to allow it to vent. (On my design, if >>capacitor shorted it would draw down the E-Bus with no way to sever short >>without 2nd relay. My design addresses failure of battery (opened or dead) >>when attempting in flight restart after soaring) > > Why not wire your PM alternator like Z-16 and leave the capacitor > across the battery all the time? **** If running on E-Bus, having a leaking capacitor that can not be disconnected will defeat much which I desire in my design. I am not using a Battery contactor, but a Flaming River switch, and turning it off will not sever the capacitor from the E-Bus. I am willing to accept the extra complexity to have this extra relay that will disconnect the capacitor when Rotax generator is turned off either by generator switch or OV. This is in addition to opening the AC with S704-1 relay. Yes kinda like wearing suspenders and a belt, but it will accomplish what I desire. My question is do you think this vented 75 amp relay will provide reasonable service living on the engine side of the firewall with regard to condensation causing problems (corrosion/contamination ingress) and or any other problems that can be associated with a vented relay? >>3) When turning on and off the internal generator, the 75 amp Bosh relay >>will be used to charge up the 22K uF capacitor. Can this relay most like >>give good service charging up the capacitor at least once per flight? >>Could the B+C S704-1 "Sealed" relay most like take the abuse of charging >>up the capacitor at least once per flight and be used in place of the Bosh >>75 amp? (Bosh weighs in at 3.1 oz and has dual contacts) > > If you're wired per the latest control philosophies for PM > alternators, the capacitor charges through the battery contactor > which won't be particularly stressed by this activity. The > act of charging the capacitor using the output of the alternator > is current limited by the alternator's dynamics. No inrush > concerns here. **** I am not precise following the latest control philosophies for PM alternators. I addressed concerns in my design to allow operations from total loss battery/s for extended soaring, failure of main battery if it occurred during an inflight restart after soaring, once motor running on a failed main battery I can get Rotax generator on line to power E-Bus, if smoke from electric, I can shut down everything and have a fuel pump running autonomous in seconds. I want to use either a 75 amp Bosh Relay or a B+C S704-1 to disconnect DC side from Generator. Do you think the 75 amp relay will hold up charging the 22K uF capacitor at least once per flight? Do you think a B+C S704-1 relay will hold up charging the 22K uF capacitor at least once per flight? Again this relay will be the tool used to make a connection and charge the capacitor. >>4) I want to use for pitch trim small "Sealed" Osram 12v 5a relays from >>Digikey pn G6B 2214P US DC12, are the chances good it will not blow apart >>if I choose to wave soar up to 35K with long wings? Will be mounted in >>cockpit. > > What kind of trim motors? You're probably fine with MAC/RayAllen > actuators. You could easily go all solid state with these duties > and eliminate the worries entirely. You're not going to "blow them > apart" . . . the risk is that at reduced pressures, the arcing > that inevitably forms between spreading contacts is more severe > and you get reduced service life. I've not tested open relays at > these altitudes . . . our mil-spec products are sealed. **** It is a Ray Allen, I forget the exact model but it is the smallest one with a indicator. Question is again about blowing them apart because the internal pressure is higher than the outside pressure at altitude. I doubt design had in mind aircraft use??? Do you think there is a good chance that they will not blow apart? Thx. Sincerely Ron Parigoris ________________________________ Message 14 ____________________________________ Time: 05:01:59 PM PST US Subject: Re: AeroElectric-List: Crimp on terminals From: Larry Mac Donald Grant, Tinned wire ends are good for wraping around screws and setting under screws in terminal blocks but crimp connectors are made to handle stranded wire. When the wire is crimped it is crushed into one homogenous mass forcing out air and gauranteeing a corrosion free joint. Also if using a stiff joint such as a tinned wire or a solid wire the crush stresses the wire and vibration will likely break the wire,sooner or later, at the joint. HTH Larry Mac Donald lm4@juno.com Rochester N.Y. Do not archive On Sat, 14 Apr 2007 08:53:47 -0700 "Grant Neilson" writes: > > > Is it a good idea to "tin" wire ends with a little solder before > using crimp > on terminals for D miniature connectors, or not? > > Grant Neilson > RV9A, finishing > > > > > > > > ________________________________ Message 15 ____________________________________ Time: 05:40:35 PM PST US Subject: Re: AeroElectric-List: curious questions From: Larry Mac Donald In the course of helping a friend construct an RV 9 I had the opportunity to examine the electrical system design. I was puzzled at the use of a master relay (solenoid) to switch the entire electrical system. A number of questions occurred to me regarding this design: The questions: How much amperage draw does the solenoid consume simply being energized? At what voltage does the Solenoid release? And why this design? _________________________________________________________________________ _____ 1. I can't say for sure but solonoids of this type usually draw between 700ma and 1A. 2. They don't release. They stay on as long as the master switch is on. _________________________________________________________________________ _______ It seems to me inserting the master relay (solenoid) into the electrical system has no benefit and some detriment. The detriments are: 1. constant draw on battery when energized. 2. greater complexity. 3. increased weight (all 6 oz of the solenoid) 4. failure of the complete electrical system if a) the solenoid fails, or b) if you have alternator failure and voltage drops low enough to allow the solenoid to not close/open Consider this. You want to connect a battery to your entire airplane,except the ignition system on certified acft. This will supply as much as 60 amps to the acft systems. If you can't disconnect it your battery will go flat overnight. So what will you use to connect/disconnect. How about a little 6oz. solonoid and a tiny, lightweight, 5 amp switch. I think that would be much better than a big old 50 amp switch in the cockpit along with the heavy cable run to the switch and then to the main buss. Now consider starting the engine. with a single wire system , and with any nav equipment left on, when you hit the starter the 200 to 300 amps that will be pulled from the battery on a cold day will cause a voltage drop that will finish off your nav equipment. So what to do ? Run a cable to a Master solonoid and run very light wires thru the firewall to the master switch. Then run a jumper cable from the first contact point of the master solonoid to the current carrying terminal of a second solonoid. The starter solonoid. And from there to the starter. And then run a couple of very light wires thru the firewall to a very light starter switch. Save a few lbs.. Save a lot of panel real eatate. HTH Larry Mac Donald lm4@juno.com Do not archive ________________________________ Message 16 ____________________________________ Time: 05:52:15 PM PST US From: "Rino Lacombe" Subject: AeroElectric-List: Alternator The following information may be useful to others. I got two small alternators, 30 Amp. with internal regulators that stop generating when the wire that is connected to the ignition is disconnected. That means I can use the field crowbar circuit to disconnect in an overvoltage situation. These alternators come from 3 cylinder Kubota diesel tractors. They are Denso 16678-6402. I use the two alternators on my dual electrical system. Rino ________________________________ Message 17 ____________________________________ Time: 06:11:54 PM PST US Subject: AeroElectric-List: Re: Battery insulation From: "Leo Holler" BobsV35B(at)aol.com wrote: > Good Afternoon Leo, > Is the RG battery he is using in his Cherokee listed as being approved for that use? > > Happy Skies, > > Old Bob > AKA > Bob Siegfried > Ancient Aviator > Stearman N3977A > Brookeridge Air Park LL22 > Downers Grove, IL 60516 > 630 985-8503 Bob, The battery is not approved for the Cherokee but is FAA PMA'd and approved for many others I'm told. They will need a 337 to finish the install per his AI. Leo See what's free at AOL.com (http://www.aol.com?ncid=AOLAOF00020000000503). > [b] > Read this topic online here: http://forums.matronics.com/viewtopic.php?p=106967#106967 ________________________________ Message 18 ____________________________________ Time: 07:06:23 PM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Re: Battery insulation In a message dated 4/14/2007 8:13:28 P.M. Central Daylight Time, leoh@gci.net writes: Bob, The battery is not approved for the Cherokee but is FAA PMA' d and approved for many others I'm told. They will need a 337 to finish the install per his AI. Leo Thank You Leo, In the event something leaks, has anyone yet investigated the suitability of the foam when it gets involved with corrosive gases? May not be considered a problem, but --- ?? Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Air Park LL22 Downers Grove, IL 60516 630 985-8503 ************************************** See what's free at http://www.aol.com. ________________________________ Message 19 ____________________________________ Time: 07:37:46 PM PST US From: "Jim Jewell" Subject: Re: AeroElectric-List: Battery insulation Leo, Without regard to FAA regs etc; Just a guess, I doubt there should be a problem with the battery box stuffed as described. If you used a hole saw to punch the foam full of holes the insulating quality of the foam would be reduced somewhat. Also the drilled foam would be less resistant to being crushed and therefore move out of the way reducing the chance of structural damage should the "overheating" or dying battery begin to expand. Who knows what would become of the battery in a crash scenario? Jim in Kelowna ----- Original Message ----- From: "Leo Holler" Sent: Saturday, April 14, 2007 1:16 PM Subject: AeroElectric-List: Battery insulation > > A friend has a Cherokee 140 with an original battery box beneath the rear > seat. He has replaced the lead acid battery with a 16 AH RG battery. The > RG battery is oriented the same as the lead acid battery had been. To keep > the new battery from flopping around (it is much smaller than the old lead > acid one) he inserted DOW HI (blue board foam) insulation around the four > sides. I don't recall seeing any insulation under or over the battery. My > question: Is this insulation OK or is there a chance that the battery > could overheat if under heavy recharge? The installation looks nice and > tidy and is very lightweight, but I'd like to make sure he is not set up > for a problem in flight. Please comment if you can. > > Leo Holler > leoh@gci.net > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=106925#106925 > > > ------------------------------------------------------------------------------------- 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.