---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 01/23/18: 8 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:50 AM - Re: Fuel Totalizer Circuit (sturs) 2. 01:39 PM - SD-8 Alternator Question (Ron Springer) 3. 01:53 PM - Re: SD-8 Alternator Question (Rene) 4. 02:44 PM - Re: SD-8 Alternator Question (Peter Pengilly) 5. 02:56 PM - Re: SD-8 Alternator Question (Ron Springer) 6. 05:26 PM - Re: SD-8 Alternator Question (ashleysc@broadstripe.net) 7. 06:06 PM - Re: SD-8 Alternator Question (Robert L. Nuckolls, III) 8. 06:47 PM - Re: SD-8 Alternator Question (OOPS) (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 12:50:09 AM PST US Subject: AeroElectric-List: Re: Fuel Totalizer Circuit From: "sturs" Thanks Paul. My friend already has a replacement - which took him a long time to find. Mind you hes rather unwilling to take the new one apart and use that as an example to check against the other! Thanks for the offer, though. Much appreciated. Cheers, Stu Read this topic online here: http://forums.matronics.com/viewtopic.php?p=477507#477507 ________________________________ Message 2 _____________________________________ Time: 01:39:05 PM PST US From: Ron Springer Subject: AeroElectric-List: SD-8 Alternator Question When I bought my plane, which has an SD-8 alternator as the primary power source, it came with an inline fuse on one of the two leads from the alternator. The guy who installed it said it was an 8 amp alternator so he added a 10 amp inline fuse. But, I believe it provides 8 amps at 14 volts after regulation and the voltage where the fuse is installed is something like 20-25 volts AC. So, the max current there would probably be a bit less than 8 amps anyway, right? Regardless, it has never blown, but I am wondering if it is even serving a useful purpose other than to increase the number of electrical connections in my plane? Thanks, Ron ________________________________ Message 3 _____________________________________ Time: 01:53:29 PM PST US From: "Rene" Subject: RE: AeroElectric-List: SD-8 Alternator Question My chief engineer here at work always says the fuse is there to protect the wire.keeps the smoke innot the equipment at the end. I have the same setup on my standby and I think that is what they gave me in the kit. Rene' 801-721-6080 From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Ron Springer Sent: Tuesday, January 23, 2018 2:37 PM Subject: AeroElectric-List: SD-8 Alternator Question When I bought my plane, which has an SD-8 alternator as the primary power source, it came with an inline fuse on one of the two leads from the alternator. The guy who installed it said it was an 8 amp alternator so he added a 10 amp inline fuse. But, I believe it provides 8 amps at 14 volts after regulation and the voltage where the fuse is installed is something like 20-25 volts AC. So, the max current there would probably be a bit less than 8 amps anyway, right? Regardless, it has never blown, but I am wondering if it is even serving a useful purpose other than to increase the number of electrical connections in my plane? Thanks, Ron ________________________________ Message 4 _____________________________________ Time: 02:44:34 PM PST US From: "Peter Pengilly" Subject: RE: AeroElectric-List: SD-8 Alternator Question See this wiring diagram =93 shows a 15 amp fuse. http://www.bandc.aero/pdfs/504-500%20REV%20I.pdf Peter From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Ron Springer Sent: 23 January 2018 21:37 Subject: AeroElectric-List: SD-8 Alternator Question When I bought my plane, which has an SD-8 alternator as the primary power source, it came with an inline fuse on one of the two leads from the alternator. The guy who installed it said it was an 8 amp alternator so he added a 10 amp inline fuse. But, I believe it provides 8 amps at 14 volts after regulation and the voltage where the fuse is installed is something like 20-25 volts AC. So, the max current there would probably be a bit less than 8 amps anyway, right? Regardless, it has never blown, but I am wondering if it is even serving a useful purpose other than to increase the number of electrical connections in my plane? Thanks, Ron ________________________________ Message 5 _____________________________________ Time: 02:56:37 PM PST US From: Ron Springer Subject: Re: AeroElectric-List: SD-8 Alternator Question Thanks! I didn't know that it was standard to include the fuse in one of the wires. The person I bought the plane from made it sound like it was his idea. The 10 amp size seems to work fine for the SD-8. The wiring diagram applies to three alternators, including ones that are larger than the SD-8, which is probably why it calls for the 15 amp fuse. Ron On Tue, Jan 23, 2018 at 5:43 PM, Peter Pengilly wrote: > See this wiring diagram =93 shows a 15 amp fuse. > > > http://www.bandc.aero/pdfs/504-500%20REV%20I.pdf > > > Peter > > > *From:* owner-aeroelectric-list-server@matronics.com [mailto: > owner-aeroelectric-list-server@matronics.com] *On Behalf Of *Ron Springer > *Sent:* 23 January 2018 21:37 > *To:* aeroelectric-list@matronics.com > *Subject:* AeroElectric-List: SD-8 Alternator Question > > > When I bought my plane, which has an SD-8 alternator as the primary power > source, it came with an inline fuse on one of the two leads from the > alternator. > > The guy who installed it said it was an 8 amp alternator so he added a 10 > amp inline fuse. But, I believe it provides 8 amps at 14 volts after > regulation and the voltage where the fuse is installed is something like > 20-25 volts AC. So, the max current there would probably be a bit less th an > 8 amps anyway, right? > > Regardless, it has never blown, but I am wondering if it is even serving a > useful purpose other than to increase the number of electrical connection s > in my plane? > > Thanks, > > Ron > ________________________________ Message 6 _____________________________________ Time: 05:26:15 PM PST US From: ashleysc@broadstripe.net Subject: Re: AeroElectric-List: SD-8 Alternator Question Hi Peter; Hi Ron; The drawing shows a ten amp fuse for an SD-8 alternator. Cheers! Stu. ----- Original Message ----- From: "Peter Pengilly" Sent: Tuesday, January 23, 2018 2:43:56 PM Subject: RE: AeroElectric-List: SD-8 Alternator Question See this wiring diagram =93 shows a 15 amp fuse. http://www.bandc.aero/pdfs/504-500%20REV%20I.pdf Peter From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectr ic-list-server@matronics.com] On Behalf Of Ron Springer Sent: 23 January 2018 21:37 Subject: AeroElectric-List: SD-8 Alternator Question When I bought my plane, which has an SD-8 alternator as the primary power s ource, it came with an inline fuse on one of the two leads from the alterna tor. The guy who installed it said it was an 8 amp alternator so he added a 10 a mp inline fuse. But, I believe it provides 8 amps at 14 volts after regulat ion and the voltage where the fuse is installed is something like 20-25 vol ts AC. So, the max current there would probably be a bit less than 8 amps a nyway, right? Regardless, it has never blown, but I am wondering if it is even serving a useful purpose other than to increase the number of electrical connections in my plane? Thanks, Ron ________________________________ Message 7 _____________________________________ Time: 06:06:58 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: SD-8 Alternator Question At 03:37 PM 1/23/2018, you wrote: >When I bought my plane, which has an SD-8 alternator as the primary >power source, it came with an inline fuse on one of the two leads >from the alternator. > >The guy who installed it said it was an 8 amp alternator so he added >a 10 amp inline fuse. But, I believe it provides 8 amps at 14 volts >after regulation and the voltage where the fuse is installed is >something like 20-25 volts AC. So, the max current there would >probably be a bit less than 8 amps anyway, right? > >Regardless, it has never blown, but I am wondering if it is even >serving a useful purpose other than to increase the number of >electrical connections in my plane? The SD-8, under some conditions, is capable of 10A of output. A fuse should be sized for at least 1.5 times the expected continuous load . . . 2x or 3x is not unreasonable giving the very fast action of a fuse versus circuit breaker. If the SD-8 feeder is 14AWG or larger, a 20A fuse is the better choice . . . 30A would not be out of line. Bob . . . ________________________________ Message 8 _____________________________________ Time: 06:47:11 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: SD-8 Alternator Question (OOPS) At 08:06 PM 1/23/2018, you wrote: >At 03:37 PM 1/23/2018, you wrote: >>When I bought my plane, which has an SD-8 alternator as the primary >>power source, it came with an inline fuse on one of the two leads >>from the alternator. >> >>The guy who installed it said it was an 8 amp alternator so he >>added a 10 amp inline fuse. But, I believe it provides 8 amps at 14 >>volts after regulation and the voltage where the fuse is installed >>is something like 20-25 volts AC. So, the max current there would >>probably be a bit less than 8 amps anyway, right? >> >>Regardless, it has never blown, but I am wondering if it is even >>serving a useful purpose other than to increase the number of >>electrical connections in my plane? > > > The SD-8, under some conditions, is capable of 10A > of output. A fuse should be sized for at least 1.5 > times the expected continuous load . . . 2x or > 3x is not unreasonable giving the very fast action > of a fuse versus circuit breaker. > > If the SD-8 feeder is 14AWG or larger, a 20A > fuse is the better choice . . . 30A would not > be out of line. Hit the 'send' button too soon. The short answer to your question: That feeder should be protected. If you've not experienced a nuisance trip of the 10A fuse, then there's no pressing need to fiddle with it. If you DO experience a nuisance trip in the future, and upsize is indicated, I'd go for 20A 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.