---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Fri 11/23/18: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 0. 04:15 AM - Just A Few Days Left... (Matt Dralle) 1. 01:41 PM - Re: Rotax 912 UL Rectifier wiring (Hugh McKay) 2. 06:14 PM - Re: 912 Bed-Mount bolt torque (Richard Girard) ________________________________ Message 0 _____________________________________ Time: 04:15:09 AM PST US From: Matt Dralle Subject: RotaxEngines-List: Just A Few Days Left... Dear Listers, There are just a few days left for this year's List Fund Raiser. If you've been putting off making a Contribution until the last minute, well, this is it! The last minute, that is... :-) There are some GREAT new gift selections to choose from this year. I personally want at least three of them! There's probably something you can't live without too! And, best of all it supports your Lists! Please remember that there isn't any sort of commercial advertising on the Lists and the *only* means of keeping these Lists running is through your Contributions during this Fund Raiser. Let's make this a "Black Friday" for the Lists! Please make a Contribution today! http://www.matronics.com/contribution Or, drop a personal check in the mail to: Matt Dralle / Matronics 581 Jeannie Way Livermore CA 94550 Thank you! Matt Dralle Matronics Email List Administrator ________________________________ Message 1 _____________________________________ Time: 01:41:50 PM PST US From: Hugh McKay Subject: RE: RotaxEngines-List: Rotax 912 UL Rectifier wiring Dave, Thank you for the additional electrical information and instruction. Refer ring to the proposed sketch I sent to you, I am proposing a revision; to ch ange out the existing 5 Amp Breaker/switch 13 to a similar 30 Amp Breaker/s witch and reconnect the wiring as follows: connect the new 30 Amp breaker/ switch between the existing 30 Amp fuse and the rectifier. All the connecti ng wire from the shunt/30 Amp fuse/ 30 Amp breaker 13, to the common connec tion point of the four rectifier wires R, B+, C, and the + capacitor wire i s stranded # 10 AWG THHN. I have made a list of all my electrical devices that would be operating dur ing taxi, take-off, cruise, and landing and calculated the electrical load for each case in amps. The largest load demand is during take-off and landi ng. The load demand during cruise is somewhat less. I notice in Phil Lockwo od=99s article he states that one should expect the Rotax Rectifier/r egulator to have a maximum output of approximately 18 Amps DC. My total ins talled electrical load is about 27 amps DC. This means that if during fligh t all of this installed electrical load was connected, the rectifier could not meet the demand and the battery would be making up the difference, thus draining the battery. But this is not the case during cruise, but is the c ase during take-off and landing. My calculated take-off and landing load de mand is about 21 Amps DC, while the cruise electrical load demand is around 11.5 Amps DC. If my thought logic is correct this means that during the sh ort periods of take-offs and landings my battery would not be charging (red light on), but during cruise it should be charging (red light off). Correc t?? By still using a Potter & Brumfield W23 series W23-X1A1G-30 push/pull b utton breaker at this point in the wiring I believe it not only protects th e wire but still allows me to isolate the battery from the rectifier when t he engine is no running. Sorry to be asking you to look at this again. Comments, advice??? Hugh G. McKay III, P.E. Fellow. L.M. ASCE Senior Consultant Worldwide Engineering Inc. 4090 North NC Hwy. 16 Denver, NC 28037 Ph. 704-661-8271 Fax 704-483-5466 Email hgmckay@bellsouth.net http://www.geo.com (click on Power Division) Sent from Mail for Windows 10 From: Dave Alberti Sent: Wednesday, November 21, 2018 10:42 PM Subject: Re: RotaxEngines-List: Rotax 912 UL Rectifier wiring Hugh, the primary function of breakers and fuses is to protect the wire. =C2-The size of the wire is sized to the expected load and voltage drop d ue to wire length. Placing a 5 amp breaker ahead of a 30 amp fuse is just a wasted fuse installation. The fuse will never see a load greater than 5 am ps. =C2-Replacing the 5 amp with a 30 makes the fuse redundant and unnece ssary. =C2-If the wire downstream is incapable of carrying more than 30 a mps it becomes the fuse. =C2-I have seen panels that smoked in RV =99s and cars and if it happens in a plane you want to be able to strip the load with the fewest switches possible. =C2-Your drawing will work to is olate the =C2-charging circuit only if the wire size matches the expected load with the caveat being you have no protection for the wire between the breaker and the battery. Dave Alberti On Nov 21, 2018, at 8:38 PM, Hugh McKay wrote: Dave, I am not an electrical guru so my understanding of electrical terms and fun ctions in an electrical circuit is very limited. I do need to limit the amo unt of changes to my panel simply due to space. Therefore, I am attaching a scanned sketch of what I propose doing, hoping that it will be safe and me et the electrical requirements for safe operation of the rectifier and give the isolation requirements described by Rotax. Please refer to the attache d sketch and the original one line to compare the proposed changes to the o riginal. =C2- You will note on the sketch that I have a common point where I connect 5 wi res to a common connection (R, B+, C, the wire from the Capacitor, and the wire from the 30 Amp fuse). Between the 30 Amp fuse and the shunt I propose using my existing Breaker 13 (Potter & Brumfield Series W23 Push Button Th ermal circuit breaker W23-X1A1G5 (which is certified to be used as a manual push to close/pull to open disconnect) rated for 5 Amps having a Trip time at 200% rating of 6-22 seconds. If necessary I can replace this same ident ical Potter & Brumfield breaker with Amp ratings up to 50 Amps. By the way all the breakers shown on the one line are panel mounted Potter & Brumfield Series W23 Push Button Thermal circuit breakers. I use these breakers rout inely as disconnect switches to isolate certain sections of the electrical system on start-up. Do you find any flaws in this sketch? =C2- Hugh G. McKay III, P.E. Fellow. L.M. ASCE Senior Consultant Worldwide Engineering Inc. 4090 North NC Hwy. 16 Denver, NC 28037 =C2- Ph. 704-661-8271 Fax 704-483-5466 Email hgmckay@bellsouth.net http://www.geo.com (click on Power Division) Sent from Mail for Windows 10 =C2- From: Dave Alberti Sent: Wednesday, November 21, 2018 1:28 PM Subject: Re: RotaxEngines-List: Rotax 912 UL Rectifier wiring =C2- Hugh, I have an actual contractor (looks like a solenoid) from Spruce desig ned to use for this application. Mine is on the firewall near my battery. =C2-My comparison position is prior to your ammeter shunt. You would have to wire your breaker so that when closed it would energize the solenoid to close the circuit supplying 12 volts to B+, R and C. =C2-I use a switch like Cessna, red split battery alternator . Dave Alberti On Nov 20, 2018, at 10:31 PM, Hugh McKay wrote: Dave, =C2- Thanks for your clarification of the Rotax instruction concerning disconnec ting the battery. I went back and read a similar article by Phil Lockwood c alled =9CTips and Tricks for the Ideal Rotax 912 Installation =9D published in 2005. In that article he clearly states that the + battery wire that is connected to R, B+, and C must be disconnected from the batte ry. Based on my wiring one line drawing where would you recommend I move Br eaker 13 to isolate the battery, and should I change the breaker to a large r amp rating? =C2- Hugh G. McKay III, P.E. Fellow. L.M. ASCE Senior Consultant Worldwide Engineering Inc. 4090 North NC Hwy. 16 Denver, NC 28037 =C2- Ph. 704-661-8271 Fax 704-483-5466 Email hgmckay@bellsouth.net http://www.geo.com (click on Power Division) Sent from Mail for Windows 10 =C2- From: Dave Alberti Sent: Tuesday, November 20, 2018 9:41 PM Subject: Re: RotaxEngines-List: Rotax 912 UL Rectifier wiring =C2- Hugh, that does not isolate the battery, the rotax drawing drops at relay 1 9 and takes all voltage off the regulator at B+ and R. =C2- Dave Alberti 414-699-9312 On Nov 20, 2018, at 7:59 PM, Hugh McKay wrote: Dave, =C2- My battery is manually isolated by Breaker 13 shown within the =9Cclo ud=9D noted as Rev.#1 on the attached one line (better drawing than w hat I sent previous). All the Breakers mounted on the panel including Break er 13 are Potter & Brumfield W23 Push Button Thermal circuit breakers that can also be used as manual isolation switches. I assumed the term =9C Master Switch=9D as used by Mr. Truemper meant the =9CIgnition Switch=9D as seen on my one line. With that switch in the =9Cof f=9D position and Breaker 13 open the voltage to ground on R, B+, and C each measured 12.7 VDC in stead of 0 VDC. This is the same wiring arrang ement as shown in the Rotax 912 Installation Manual, page 46 of 66 Dated 19 97 03 26. Unless I am =9Csomewhere lost in translation=9D, If M r. Truemper has his engine wired according to the Rotax manual (which is th e same as mine, he should also be reading the voltage to ground on R, B+, a nd C each as 12+ VDC in stead of 0 VDC =C2- Having said all this, have I lost my mind?? According to the attached one l ine is my electrical system wired correctly???? =C2- =C2- Hugh G. McKay III, P.E. Fellow. L.M. ASCE Senior Consultant Worldwide Engineering Inc. 4090 North NC Hwy. 16 Denver, NC 28037 =C2- Ph. 704-661-8271 Fax 704-483-5466 Email hgmckay@bellsouth.net http://www.geo.com (click on Power Division) Sent from Mail for Windows 10 =C2- From: Dave Alberti Sent: Tuesday, November 20, 2018 7:23 PM Subject: Re: RotaxEngines-List: Rotax 912 UL Rectifier wiring =C2- You don=99t show a battery relay to that isolates the battery when al l switches are off (as in shutdown) which is in the rotax install wiring di agram. =C2-I believe that is the master that =C2-Truemper=99s spe aking about. Dave Alberti 414-699-9312 On Nov 20, 2018, at 3:46 PM, Hugh McKay wrote: I need some advice by anyone out there who may be able to clear up a questi on I have concerning checking the output wiring of the standard Rotax 912 r ectifier used with the 912 UL engine. I have this rectifier on my =C2-All egro 2000 ELSA (912 UL engine). For additional information I am attaching m y airplane wiring one line diagram that shows how my rectifier is wired. Al so I want to make reference to a Blog article authored by Klaus Truemper ti tled =9C18 December 2012 Testing Rotax 912/914 Generator and Rectifie r=9D. You can Google the title and read the article. =C2- In the section of Mr. Truemper=99s article (Testing Regulator/Rectifi er) where he states =9CWith the Master switch off: The above test (re ferring to the previous paragraph) should show 0 voltage for all three case s. I do not know what Mr. Truemper=99s wiring diagram looked like bec ause he did not offer one in his article. =C2- After reading Mr. Truemper=99s article and because of some perceived battery charging issues I was having with my airplane I thought I would che ck my rectifier according to his instructions in the article section titled (Testing Regulator/Rectifier). All the tests he listed (the same ones I di d) fell within the values stated in his article except those tested with th e Master switch =9Coff=9D. In my case, with the Master switch =9Coff=9D the voltage to ground on R, B+, and C each measured 1 2.7 VDC in stead of 0 VDC. =C2- Again I don=99t have Mr. Truemper=99s wiring diagram, but in th e wiring diagram shown in the Rotax 912 UL engine installation manual their wiring diagram indicates that there will be regular 12 VDC battery voltage on R, B+, and C when the master switch is =9Coff=9D. =C2- My question is this: Assuming there is a disconnect switch between terminal C and B+ in the open position (per instruction from Rotax to protect the b attery from discharge), with the Master switch in the =9Coff=9D position should I be measuring 12+VDC to ground on R, B+, and C rather tha n 0 VDC?? =C2- Hugh G. McKay III, P.E. Fellow. L.M. ASCE Senior Consultant Worldwide Engineering Inc. 4090 North NC Hwy. 16 Denver, NC 28037 =C2- Ph. 704-661-8271 Fax 704-483-5466 Email hgmckay@bellsouth.net http://www.geo.com (click on Power Division) Sent from Mail for Windows 10 =C2- =C2- =C2- =C2- ________________________________ Message 2 _____________________________________ Time: 06:14:28 PM PST US From: Richard Girard Subject: Re: RotaxEngines-List: 912 Bed-Mount bolt torque If it's a 8 X 1.25 that's close to a 5/16-18 for me and I wouldn't go beyond 14 ft lb and use Loctite 243 to keep it tight. The HMM specifies 17.7 ft lb for unlisted M8. I guess that gives you 16 ft lb +/- 1.5 ft lb. :-}. Rick On Thu, Nov 22, 2018 at 10:15 AM edflys2 wrote: > > Have a 912ULS configured with a bed mount. I am trying to determine the > correct torque for the cap screws that hold the Zenair steel Angle Bracke ts > to the bottom of the crank case (Sonex call them "Engine Mount Attach > Bars"). I find various recommended torque values for the M8 cap screws as > high as 26 ft lbs, which seems high for a bolt screwed into an aluminum > crank case. > > Any advise appreciated. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=485503#485503 > > =========== =========== =========== =========== =========== =========== > > -- =9CBlessed are the cracked, for they shall let in the light.=9D Groucho Marx ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rotaxengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RotaxEngines-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/rotaxengines-list Browse Digests http://www.matronics.com/digest/rotaxengines-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.