---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 08/16/15: 9 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:12 AM - Bending copper (bus) bar (JOHN TIPTON) 2. 09:07 AM - Re: Bending copper (bus) bar (Robert L. Nuckolls, III) 3. 09:20 AM - Re: Re: Newbie with PM alternator feed question (Robert L. Nuckolls, III) 4. 09:26 AM - Re: Re: Newbie with PM alternator feed question (Robert L. Nuckolls, III) 5. 09:33 AM - Re: Bending copper (bus) bar (Stuart Hutchison) 6. 09:34 AM - Re: Bending copper (bus) bar (Stuart Hutchison) 7. 09:46 AM - Re: electrical system planning (Robert L. Nuckolls, III) 8. 08:06 PM - Re: Newbie with PM alternator feed question (user9253) 9. 09:31 PM - Re: electrical system planning (Ryan Brown) ________________________________ Message 1 _____________________________________ Time: 07:12:33 AM PST US Subject: AeroElectric-List: Bending copper (bus) bar From: "JOHN TIPTON" Hi Guys I'll be using the almost (standard) method for connecting the battery contactor to starter contactor on a Rv9a with copper bar, also using a lighter gauge copper bar from the live feed to the ammeter shunt, this requires a bend in the copper bar: should copper bar be bent cold or with heat applied Regards John Read this topic online here: http://forums.matronics.com/viewtopic.php?p=446020#446020 ________________________________ Message 2 _____________________________________ Time: 09:07:59 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Bending copper (bus) bar At 09:10 AM 8/16/2015, you wrote: > > >Hi Guys > >I'll be using the almost (standard) method for connecting the >battery contactor to starter contactor on a Rv9a with copper bar, >also using a lighter gauge copper bar from the live feed to the >ammeter shunt, this requires a bend in the copper bar: should copper >bar be bent cold or with heat applied What are the dimensions of the "bar"? I usually make such parts from 0.06 to 0.09 material and just bend it cold over a not-sharp radius . . . ~ 1/8" Bob . . . ________________________________ Message 3 _____________________________________ Time: 09:20:04 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Newbie with PM alternator feed question > >(1) Is dynamo current "self limiting" a characteristic of all 3 >phase PM type alternators? (dynamos?) Would gladly eliminate those >three 20 amp c/b's if not required! the PM alternators will self-destruct if presented with a hard short on their windings generated by failure of the rectifier=regulator. Use in-line fuses. One for the single phase machines, two for the three phase machines. These need no be crew- accessible. >(2) Was planning on a 40A ANL type fuse for the 10 ga wire from the >relay to the primary bus. What is the rated output of your altenrator? An inline maxi-fuse of next-step higher value would be fine and a lot less bulky. >(3) Was not planning on fuse/circuit protection from the battery to >the primary bus. Most people do not . . . including hundreds of thousands of TC aircraft. Bob . . . ________________________________ Message 4 _____________________________________ Time: 09:26:16 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Newbie with PM alternator feed question At 05:59 PM 8/10/2015, you wrote: > >Follow on questions... > >Having trouble reconciling the tinyurl link wiring that you posted >versus the wiring diagram for the B&C OVPM package (505-500) I >planned on using. Appear to be only one relay to control on/off of >the alternator via the capacitor and R/R versus your sketch with two >relays for two of three phases. Also, why the need to fuse each >phase of the alternator prior to the R/R as depicted in the B&C >diagram? I feel like I'm missing parts of the big picture [Embarassed] OV protection is a separate issue from the protection of wires. The single pole relay in series with the DC output of a R/R ALWAYS works to protect the ship's systems. However, that relay ALSO serves the legacy purpose of offering any time, any conditions, ON-OFF control of the engine driven power source from the pilot's position. If one embraces the goal of generating a MAX COLD power condition for ALT OFF then one is encouraged to open the power source as far upstream as practical. Hence, relay(s) in the AC winding leads. You need to break TWO leads of a 3-phase machine to bring it to heel. A two-pole relay would work . . . but inexpensive, automotive relays in 2-poles at that current are more rare and expensive that using two, robust single-pole devices to do the job. Two relays was a cost-of-ownership . . . not a functional design decision. Bob . . . ________________________________ Message 5 _____________________________________ Time: 09:33:31 AM PST US Subject: Re: AeroElectric-List: Bending copper (bus) bar From: Stuart Hutchison If you bend thin material once with a blunt radius, say 1/8, then cold is fine. If you do more bending it will work harden and may crack under stress and vibration. In difference to steel, annealing copper is achieved by heating to cherry hot and quenching in water or oil. > On 16 Aug 2015, at 18:10, JOHN TIPTON wrote: > > > Hi Guys > > I'll be using the almost (standard) method for connecting the battery contactor to starter contactor on a Rv9a with copper bar, also using a lighter gauge copper bar from the live feed to the ammeter shunt, this requires a bend in the copper bar: should copper bar be bent cold or with heat applied > > Regards > > John > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=446020#446020 > > > > > > > > > > ________________________________ Message 6 _____________________________________ Time: 09:34:37 AM PST US Subject: Re: AeroElectric-List: Bending copper (bus) bar From: Stuart Hutchison If you bend thin material once with a blunt radius, say 1/8, then cold is fine. If you do more bending it will work harden and may crack under stress and vibration. In difference to steel, annealing copper is achieved by heating to cherry hot and quenching in water or oil. Cheers, Stu > On 16 Aug 2015, at 18:10, JOHN TIPTON wrote: > > > Hi Guys > > I'll be using the almost (standard) method for connecting the battery contactor to starter contactor on a Rv9a with copper bar, also using a lighter gauge copper bar from the live feed to the ammeter shunt, this requires a bend in the copper bar: should copper bar be bent cold or with heat applied > > Regards > > John > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=446020#446020 > > > > > > > > > > ________________________________ Message 7 _____________________________________ Time: 09:46:35 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: electrical system planning At 04:55 PM 8/10/2015, you wrote: >I'm working on figuring out the system architecture for my plane. THE VERY FIRST TASK in crafting the elegant solution for architecture in a projet like yours is to download this form: http://tinyurl.com/7jqypwj and develop a load-picture for the various phases of flight. Do one page for each bus. Electrically dependent engine stuff on battery bus, plan-b loads on and E-bus, everything else on the main bus. THEN . . . set design goals for endurance under an alternator out condition and either size a WELL MAINTAINED battery to meet that goal or craft some combination of battery and second alternator to meet the goal. Then let's talk about the architecture that's most friendly to meeting your design goals. Are those 5A figures REAL, MEASURED current values? Breaker sizes from a wiring diagram are never indicative of ENERGY required to operate the system. This is a study the economics of energy management to achieve operational goals that determine whether a failure is an emergency or a ho-hum event. Bob . . . ________________________________ Message 8 _____________________________________ Time: 08:06:45 PM PST US Subject: AeroElectric-List: Re: Newbie with PM alternator feed question From: "user9253" > the PM alternators will self-destruct if presented > with a hard short on their windings generated by > failure of the rectifier=regulator. Bob, What self destructs, the winding or the magnets or both? I am guessing the magnets only but do not know. Was I wrong to state that all alternators are self current limiting? Thanks, Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=446059#446059 ________________________________ Message 9 _____________________________________ Time: 09:31:42 PM PST US From: Ryan Brown Subject: Re: AeroElectric-List: electrical system planning Thanks Bob. The 5A figures are the estimates I got from the manufacturer for average consumption. I haven't measured it myself. The breaker size is 10A. I filled out a spreadsheet with the load analysis for each stage here: https://goo.gl/0FPFIQ I'm not entirely sure I have everything assigned to the right bus. I estimate the plane will hold 5.5 hours of fuel, so I guess that's what my endurance goal should be. That's over 70 amp hours just to keep the engine running, so it seems a backup alternator is a better bet than batteries. One question I have is if my endurance goal should be 5.5 hours with pitot heat on. I don't plan on tons of ifr flight, and I kind of doubt my brain could handle 5 hours of instrument flight. So it seems like lower endurance for ifr cruise could be acceptable. If I do want to keep the heater on with the backup alternator I need a little more than 20 amps. I'm a little confused looking at the alternators here. The SD-20 is described as a 20/30A alternator. What does that mean. I saw some mention that the vacuum pad on a continental spins faster, does that mean it's 30A on a continental and 20A on a lycoming? The plane power FS14 is just listed as 30A, so I assume it can actually put out 30A on a lycoming. On Sun, Aug 16, 2015 at 9:50 AM Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 04:55 PM 8/10/2015, you wrote: > > I'm working on figuring out the system architecture for my plane. > > > THE VERY FIRST TASK in crafting the elegant solution > for architecture in a projet like yours is to download > this form: > > http://tinyurl.com/7jqypwj > > and develop a load-picture for the various > phases of flight. > > Do one page for each bus. Electrically dependent > engine stuff on battery bus, plan-b loads on > and E-bus, everything else on the main bus. > > THEN . . . set design goals for endurance under > an alternator out condition and either > size a WELL MAINTAINED battery to meet that > goal or craft some combination of battery and > second alternator to meet the goal. > > Then let's talk about the architecture that's > most friendly to meeting your design goals. > > Are those 5A figures REAL, MEASURED current > values? Breaker sizes from a wiring diagram > are never indicative of ENERGY required to > operate the system. > > This is a study the economics of energy > management to achieve operational goals > that determine whether a failure is > an emergency or a ho-hum event. > > 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.