---------------------------------------------------------- RV-List Digest Archive --- Total Messages Posted Tue 02/05/13: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:09 AM - SD-20 Alternator / SB1B-14 regulator failure modes (Ralph E. Capen) 2. 07:32 AM - Re: SD-20 Alternator / SB1B-14 regulator failure modes (Carl Froehlich) 3. 07:32 AM - Re: SD-20 Alternator / SB1B-14 regulator failure modes (Larry Bowen) 4. 07:59 AM - Re: SD-20 Alternator / SB1B-14 regulator failure modes (Ralph E. Capen) ________________________________ Message 1 _____________________________________ Time: 05:09:45 AM PST US From: "Ralph E. Capen" Subject: RV-List: SD-20 Alternator / SB1B-14 regulator failure modes Looking to see if anyone has ever experienced a failure of either of these two types of units. This is a backup unit be design so a failure might not get noticed - until you need it. My start-up checklist has me powering on the backup unit first, checking for amps generated and the warning light on...then power up the primary unit - I get more amps and the secondary light goes out... Not looking to bad-mouth anyone.....my back-up alternator did not come on-line during my start-up checklist. No biggie - I was going on a local VFR fun flight close enough to get back to home-plate if necessary. Anyone experienced anything with theirs - how did it present? what was the cause? How did you determine / diagnose? What did you do to repair? My line of troubleshooting thinking has me first checking to make sure the unit turns when the engine turns - then looking at the two ckt breakers and finally testing for current at the field wire on the back of the alternator. Thanks, Ralph Capen ________________________________ Message 2 _____________________________________ Time: 07:32:43 AM PST US From: Carl Froehlich Subject: Re: RV-List: SD-20 Alternator / SB1B-14 regulator failure modes Yep - had a neighbor with a failed unit on his 360 Lancair. After troubleshooting a mess of wiring, I told him to pull the alternator for bench testing. Turns out the alternator rotor shaft sheared at the coupling to the accessory drive gear. I think I remember this being a phenolic piece - but I could be wrong. When are you going to swing by Dogwood? Carl On Feb 5, 2013, at 8:08 AM, "Ralph E. Capen" wrote: > > Looking to see if anyone has ever experienced a failure of either of these two types of units. This is a backup unit be design so a failure might not get noticed - until you need it. My start-up checklist has me powering on the backup unit first, checking for amps generated and the warning light on...then power up the primary unit - I get more amps and the secondary light goes out... > > Not looking to bad-mouth anyone.....my back-up alternator did not come on-line during my start-up checklist. No biggie - I was going on a local VFR fun flight close enough to get back to home-plate if necessary. Anyone experienced anything with theirs - how did it present? what was the cause? How did you determine / diagnose? What did you do to repair? > > My line of troubleshooting thinking has me first checking to make sure the unit turns when the engine turns - then looking at the two ckt breakers and finally testing for current at the field wire on the back of the alternator. > > Thanks, > Ralph Capen > > > > > > > ________________________________ Message 3 _____________________________________ Time: 07:32:44 AM PST US Subject: Re: RV-List: SD-20 Alternator / SB1B-14 regulator failure modes From: Larry Bowen The one failure I happen to see was when I could turn the unit by hand. I could feel some resistance from the magnets, but not much else. I don't know the final diagnosis of that unit. On Tuesday, February 5, 2013, Ralph E. Capen wrote: > > > > Looking to see if anyone has ever experienced a failure of either of these > two types of units. This is a backup unit be design so a failure might not > get noticed - until you need it. My start-up checklist has me powering on > the backup unit first, checking for amps generated and the warning light > on...then power up the primary unit - I get more amps and the secondary > light goes out... > > Not looking to bad-mouth anyone.....my back-up alternator did not come > on-line during my start-up checklist. No biggie - I was going on a local > VFR fun flight close enough to get back to home-plate if necessary. Anyone > experienced anything with theirs - how did it present? what was the cause? > How did you determine / diagnose? What did you do to repair? > > My line of troubleshooting thinking has me first checking to make sure the > unit turns when the engine turns - then looking at the two ckt breakers and > finally testing for current at the field wire on the back of the alternator. > > Thanks, > Ralph Capen > > -- -- Larry Bowen Larry@BowenAero.com http://BowenAero.com ________________________________ Message 4 _____________________________________ Time: 07:59:02 AM PST US From: "Ralph E. Capen" Subject: Re: RV-List: SD-20 Alternator / SB1B-14 regulator failure modes Thanks - the shaft is not metal (IIRC) and is my first step in the diagnostics (after checking the two ckt breakers). Still trying to get my engine re-broke-in. The back-up alternator is keeping me in VMC and within battery-distance to homeplate for now. You're a short hop (over the bay and Pax River) so it's near the top of my list..... -----Original Message----- >From: Carl Froehlich >Sent: Feb 5, 2013 10:31 AM >To: "rv-list@matronics.com" >Subject: Re: RV-List: SD-20 Alternator / SB1B-14 regulator failure modes > > >Yep - had a neighbor with a failed unit on his 360 Lancair. After troubleshooting a mess of wiring, I told him to pull the alternator for bench testing. Turns out the alternator rotor shaft sheared at the coupling to the accessory drive gear. I think I remember this being a phenolic piece - but I could be wrong. > >When are you going to swing by Dogwood? > >Carl > >On Feb 5, 2013, at 8:08 AM, "Ralph E. Capen" wrote: > >> >> Looking to see if anyone has ever experienced a failure of either of these two types of units. This is a backup unit be design so a failure might not get noticed - until you need it. My start-up checklist has me powering on the backup unit first, checking for amps generated and the warning light on...then power up the primary unit - I get more amps and the secondary light goes out... >> >> Not looking to bad-mouth anyone.....my back-up alternator did not come on-line during my start-up checklist. No biggie - I was going on a local VFR fun flight close enough to get back to home-plate if necessary. Anyone experienced anything with theirs - how did it present? what was the cause? How did you determine / diagnose? What did you do to repair? >> >> My line of troubleshooting thinking has me first checking to make sure the unit turns when the engine turns - then looking at the two ckt breakers and finally testing for current at the field wire on the back of the alternator. >> >> Thanks, >> Ralph Capen >> >> >> >> >> >> >> > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rv-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RV-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/rv-list Browse Digests http://www.matronics.com/digest/rv-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.