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Extra credit quiz

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Erich_Weaver(at)URSCorp.c
Guest

Posted: Mon Mar 19, 2007 8:24 am Post subject: Extra credit quiz

I was glad to see anything promoting the Aeroelectric connection, but found the article to have very limited information.  What really bugged me was that the pictures of connectors were for ones that are NOT recommended.  To be fair, this was pointed out in the caption, but how about showing people what the good ones look like instead of leaving people guessing?

 

 Erich Weaver

 

   [quote][b]

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nuckollsr(at)cox.net
Guest

Posted: Tue Mar 20, 2007 5:17 am Post subject: Extra credit quiz

At 12:22 PM 3/19/2007 -0400, you wrote:



 	  Quote: 	
		  I was glad to see anything promoting the Aeroelectric connection, but 

found the article to have very limited information. What really bugged me 

was that the pictures of connectors were for ones that are NOT 

recommended. To be fair, this was pointed out in the caption, but how 

about showing people what the good ones look like instead of leaving 

people guessing?


	


    I think the thrust of the article was about

    the seminars, not so much simple ideas.

    Did you spot any errors in simple ideas beyond the

    terminal illustration?



        Bob . . .



        ----------------------------------------

        ( IF one aspires to be "world class",  )

        ( what ever you do must be exercised   )

        ( EVERY day . . .                      )

        (                  R. L. Nuckolls III  )

        ----------------------------------------

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Erich_Weaver(at)URSCorp.c
Guest

Posted: Tue Mar 20, 2007 10:20 pm Post subject: Extra credit quiz

Bob said "Did you spot any errors in simple ideas...?"

 

 Okay, now I see what you intended - should have paid more attention to the thread subject line.

 

 Perusing the Kit Planes article once more, the information regarding the correct size fuse or circuit breader for a 60-amp alternator doesnt sound like what I thought I learned in the 'Connection.  The article says use  70 or 80 amps to "prevent nuisance tripping because alternator ratings are minimum ratings."  I believe nuisance tripping on my Z-13/8 based system with 40 amp alternator is handeled not by oversizing a fuse or breaker on the alternator B-lead, but by using a 5-amp breaker on the alternator field.  My B-lead is protected with a 40 amp ANL current limiter which I believe is the correct size for my alternator.

 

 Im also bothered by the "minimum rating" part of the statement, as this would seem to imply that the alternator could easily produce that current for long periods of time.  We are supposed to be operating at about 75% of the alternator rating, no?

 

 Is this more on track, or do I get the booby prize and have to go back and read 'Connection yet again until it finally sinks in?

 

 Erich Weaver

 This e-mail and any attachments are confidential. If you receive this message in error or are not the intended recipient, you should not retain, distribute, disclose or use any of this information and you should destroy the e-mail and any attachments or copies.  [quote][b]

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mprather(at)spro.net
Guest

Posted: Wed Mar 21, 2007 8:57 am Post subject: Extra credit quiz

Erich,



Your method of protecting the b-lead is correct as well.



Minimum rating means that the manufacturer is telling you their product

will produce at least a certain number of watts of electrical energy under

certain conditions.  Under more favorable conditions (cold temperature)

the alternator likely is capable of producing more power.  If you bought a

560Watt alternator (14V*40A) and it only produced 500Watts (while

duplicating the test conditions), you'd be rightly disappointed.

Regards,



Matt-



 	  Quote: 	
		  



 Bob said "Did you spot any errors in simple ideas...?"



 Okay, now I see what you intended - should have paid more attention to the

 thread subject line.



 Perusing the Kit Planes article once more, the information regarding the

 correct size fuse or circuit breader for a 60-amp alternator doesnt sound

 like what I thought I learned in the 'Connection.  The article says use

 70

 or 80 amps to "prevent nuisance tripping because alternator ratings are

 minimum ratings."  I believe nuisance tripping on my Z-13/8 based system

 with 40 amp alternator is handeled not by oversizing a fuse or breaker on

 the alternator B-lead, but by using a 5-amp breaker on the alternator

 field.  My B-lead is protected with a 40 amp ANL current limiter which I

 believe is the correct size for my alternator.



 Im also bothered by the "minimum rating" part of the statement, as this

 would seem to imply that the alternator could easily produce that current

 for long periods of time.  We are supposed to be operating at about 75% of

 the alternator rating, no?



 Is this more on track, or do I get the booby prize and have to go back and

 read 'Connection yet again until it finally sinks in?



 Erich Weaver

 This e-mail and any attachments are confidential. If you receive this

 message in error or are not the intended recipient, you should not retain,

 distribute, disclose or use any of this information and you should destroy

 the e-mail and any attachments or copies.

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

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nuckollsr(at)cox.net
Guest

Posted: Wed Mar 21, 2007 4:49 pm Post subject: Extra credit quiz

At 02:18 AM 3/21/2007 -0400, you wrote:



 	  Quote: 	
		  Bob said "Did you spot any errors in simple ideas...?"



Okay, now I see what you intended - should have paid more attention to the 

thread subject line.



Perusing the Kit Planes article once more, the information regarding the 

correct size fuse or circuit breader for a 60-amp alternator doesnt sound 

like what I thought I learned in the 'Connection.  The article says 

use  70 or 80 amps to "prevent nuisance tripping because alternator 

ratings are minimum ratings."  I believe nuisance tripping on my Z-13/8 

based system with 40 amp alternator is handeled not by oversizing a fuse 

or breaker on the alternator B-lead, but by using a 5-amp breaker on the 

alternator field.  My B-lead is protected with a 40 amp ANL current 

limiter which I believe is the correct size for my alternator.


	


    There's breakers, fuses and THEN there are current limiters.

    The ANL's trip characteristics are shown in . . .



http://www.aeroelectric.com/Mfgr_Data/Fuses_and_Current_Limiters/Bussman/ANL_Specs.pdf

    There's no listing for the ANL40 but note that the ANL35 goes

    asymptotic to never-trips at about 90 amps! The ANL40 will

    be higher yet. Obviously, these critters are NOT intended to

    protect for wire overheat but HARD faults. You could use an

    ANL40 on a 60A alternator without nuisance tripping.



    You COULD go for an ANN40. See . . .

http://www.aeroelectric.com/Mfgr_Data/Fuses_and_Current_Limiters/Bussman/ANN_Specs.pdf



    Here the device goes asymptotic to never-trips at 50A. An ANN40

    would be solid at about 56A . . . still really good headroom for

    a 40A alternator.



    Let's consider a MAX40 for your 40A alternator. See . . .



http://www.aeroelectric.com/Mfgr_Data/Fuses_and_Current_Limiters/Bussman/MAXI_Specs.pdf



    This device doesn't go asymptotic at under 100 seconds

    but still takes 60A to open it in about two minutes. But

    your 40A alternator will put out 50A or so when it's cold.

    Hmmmm . . . starting to push the limits.



    Lets look at a 40A breaker like . . .



http://www.aeroelectric.com/Mfgr_Data/Breakers/Potter_Brumfield/W2331_DS.pdf



    Note in the calibration data we read: "Will carry 100%

    of rating but may trip between 101% and 134% of rating.

    Must trip within one hour at 135%."  Things change pretty

    quickly in the range of 135 to 200% and drop to seconds

    of trip time.



    These are but a few examples of how much variability you can

    find in characteristics of the various circuit protection

    products when compared with their RATINGS.



    My writings have suggested the fast devices like fuses and

    breakers have healthy margins over the ratings of the

    alternator. Again, b-lead protection is for taming HARD

    faults (read many hundreds of amps) and not enduring low

    level overloads.



    Bottom line is that you probably can't have b-lead

    protection that is TOO big when selecting breakers and/or

    fuses. Anywhere from 1.5 to 3x the alternator rating

    would do the hard fault protection job and be free of

    nuisance tripping.



    On the other hand, current limiters are offered with those

    headrooms already built in. They're much more robust with

    respect to ratings than their faster cousins.

 	  Quote: 	
		  Im also bothered by the "minimum rating" part of the statement, as this 

would seem to imply that the alternator could easily produce that current 

for long periods of time.  We are supposed to be operating at about 75% of 

the alternator rating, no?


	


    You want to plan no more than 75% of rating for continuous

    loads by your ship's equipment as defined by the various

    operating conditions in your load analysis. See:



http://www.aeroelectric.com/PPS/Load_Analysis/Revised%20%20load_analysis.xls



or if you want to do one by hand see:



http://www.aeroelectric.com/PPS/Load_Analysis/Blank_Form.pdf



    The idea behind alternator de-rating is to leave some stuff

    left over for RECHARGING the BATTERY. You don't want to launch

    in some condition that needs 100% of alternator output and

    leave your battery unattended.



 	  Quote: 	
		  Is this more on track, or do I get the booby prize and have to go back and 

read 'Connection yet again until it finally sinks in?


	


    Hmmmm . . . here's a chance to redeem yourself. How

    accurate was he with respect to quotation of mile

    stones in voltage readings?



    Actually, his piece was pretty accurate for someone

    who is attempting a good critique of an activity that

    was not his particular field of experience. We romp

    along pretty fast in those seminars and we know it's

    tough to be 100% retentive in the best of circumstances.



    I'm working on the power point presentation for a

    seminar next Saturday in North Carolina. My seminar

    format is in transition in preparation for offing

    audio/slide and ultimately video versions off the

    website. This will allow us to reach many more

    individuals than those opportunities offered at

    6-8 seminars a year.



    Bob . . .

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Erich_Weaver(at)URSCorp.c
Guest

Posted: Thu Mar 22, 2007 6:01 pm Post subject: Extra credit quiz

Bob wrote: "Hmmmm . . . here's a chance to redeem yourself. How

 accurate was he with respect to quotation of mile

 stones in voltage readings?"

 

 Well that narrows it down quite a bit, ensuring complete and immediate public humiliation upon any further displays of my electrical ineptness : )

 

 Then again, I didnt have far to go to reach that state anyway, so for the purposes of List entertainment, I will go forward with my second answer to the quiz.

 

 The article states "A fully charged, healthy battery will show 12.5 voltes, and a fully discharged battery will show 10.5 volts."   Fair enough.  But shortly thereafter, it goes on to state:  "Where do you want to set you low voltage warning?  How about 13.9 volts, which indicates hat the alternator isnt charging and you're running off the stored battery charge."

 

 Setting the warning at 13.9 volts seems a tad high to me - I would expect battery-only operations to exhibit a voltage significantly less than this, especially if there was any load at all.  Heck, voltage may well drop to below this value just from going through the bridge rectifier to my e-bus.  How about a setting more like 13.0 volts or so?

 

 Regardless of quiz results, I am so pleased to have been able to do my electrical wiring myself. I pretty much stuck with the Z-13/8 schematic, because time after time I have seen people overthinking it with "improvements" that just plain arent.  Plus, even if I'm issing the nuances of breakers vs. current limiters, Bob has my rear covered. Thanks for the 'Connection and this list Bob.

 

 Erich Weaver

 This e-mail and any attachments are confidential. If you receive this message in error or are not the intended recipient, you should not retain, distribute, disclose or use any of this information and you should destroy the e-mail and any attachments or copies.  [quote][b]

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

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nuckollsr(at)cox.net
Guest

Posted: Thu Mar 22, 2007 7:25 pm Post subject: Extra credit quiz

At 10:00 PM 3/22/2007 -0400, you wrote:



 	  Quote: 	
		  Bob wrote: "Hmmmm . . . here's a chance to redeem yourself. How

accurate was he with respect to quotation of mile

stones in voltage readings?"



Well that narrows it down quite a bit, ensuring complete and immediate 

public humiliation upon any further displays of my electrical ineptness : )



Then again, I didnt have far to go to reach that state anyway, so for the 

purposes of List entertainment, I will go forward with my second answer to 

the quiz.



The article states "A fully charged, healthy battery will show 12.5 

voltes, and a fully discharged battery will show 10.5 volts."   Fair 

enough.  But shortly thereafter, it goes on to state:  "Where do you want 

to set you low voltage warning?  How about 13.9 volts, which indicates hat 

the alternator isnt charging and you're running off the stored battery charge."



Setting the warning at 13.9 volts seems a tad high to me - I would expect 

battery-only operations to exhibit a voltage significantly less than this, 

especially if there was any load at all.  Heck, voltage may well drop to 

below this value just from going through the bridge rectifier to my 

e-bus.  How about a setting more like 13.0 volts or so?


	


   BINGO! You win the six pac . . .

 	  Quote: 	
		  Regardless of quiz results, I am so pleased to have been able to do my 

electrical wiring myself. I pretty much stuck with the Z-13/8 schematic, 

because time after time I have seen people overthinking it with 

"improvements" that just plain arent.  Plus, even if I'm issing the 

nuances of breakers vs. current limiters, Bob has my rear covered. Thanks 

for the 'Connection and this list Bob.


	


   You're most welcome. Couldn't do it if it wasn't fun.



   Bob . . .



        ----------------------------------------

        ( IF one aspires to be "world class",  )

        ( what ever you do must be exercised   )

        ( EVERY day . . .                      )

        (                  R. L. Nuckolls III  )

        ----------------------------------------

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

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