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Relays 'G's" skunk stink

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nuckollsr(at)cox.net
Guest

Posted: Tue Oct 03, 2006 3:57 am Post subject: Relays 'G's" skunk stink

At 08:07 AM 10/2/2006 -0700, you wrote:



 	  Quote: 	
		  



I think it is time for someone with a little authority to clear this up. 

My authority is so little that I have hidden it under one of the periods 

in this posting. A prize awaits the one who finds it.



1) Relay mounting. Type 70 Stancor Rodgers White Emerson Tyco. See:



http://www.alliedelec.com/Images/Products/Datasheets/BM/STANCOR/Stancor_Industrial-Control_5760005.pdf



So the manufacturer says, "mount plunger vertical, cap down". I checked 

into the engineering data on this part and of course the corporate 

conglomeratization has destroyed the engineering knowledge that built the 

part. The manufacturer PROMISED they'd get back to me.....It's not DO-160 

bubela. And it's only 122 deg F max operating temp. Etc. etc.


	


    Why would you suppose they would make this recommendation?

    Is the engineering knowledge behind the recommendation

    so esoteric that we cannot deduce it for ourselves?

 	  Quote: 	
		    Use the Kilovac EV200 part if you can.


	


   Of course everyone CAN . . . it's a matter of trades.

   What is the return on investment for the trade . . .

   and is there more than one trade?



   <snip>

 	  Quote: 	
		  "Everything you've learned in school as "obvious" becomes less and less 

obvious as you begin to study the universe. For example, there are no 

solids in the universe. There's not even a suggestion of a solid. There 

are no absolute continuums. There are no surfaces. There are no straight 

lines."

    - R. Buckminster Fuller


	




   Interesting quotation . . . I'm fond of quotations

   that offer simple-ideas of easily discovered utility.

   How would you propose we use the learned gentleman's

   to guide our deliberations?



        Bob . . .

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

      < You can never learn less, you can only learn more.    >

      <    R. Buckminster Fuller                              >

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

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Eric M. Jones

Joined: 10 Jan 2006
Posts: 565
Location: Massachusetts

Posted: Tue Oct 03, 2006 12:37 pm Post subject: Re: Relays 'G's

Eric said:

 	  Quote: 	
		  I think it is time for someone with a little authority to clear this up. 

My authority is so little that I have hidden it under one of the periods 

in this posting. A prize awaits the one who finds it. 



1) Relay mounting. Type 70 Stancor Rodgers White Emerson Tyco. See: 



http://www.alliedelec.com/Images/Products/Datasheets/BM/STANCOR/Stancor_Industrial-Control_5760005.pdf 



So the manufacturer says, "mount plunger vertical, cap down". I checked 

into the engineering data on this part and of course the corporate 

conglomeratization has destroyed the engineering knowledge that built the 

part. The manufacturer PROMISED they'd get back to me.....It's not DO-160 bubela. And it's only 122 deg F max operating temp. Etc. etc. 	
 



Bob replied:  	  Quote: 	
		  Why would you suppose they would make this recommendation? Is the engineering knowledge behind the recommendation so esoteric that we cannot deduce it for ourselves? 	




I assume we can figure it out. My analysis is that the type-70 contactor has poor water-tightness (especially around the electrical terminals). This is a bit less of a problem with the cap down. Also, when energized the plunger contacts an iron stop that is part of the magnetic circuit when closed. There is no room in the space and the plunger MUST be allowed to contact the stop or the coil will draw excessive current, etc.--The cap-down orientation prevents accumulation of debris in the plunger-stop space. So my vote is that gravity is the lesser issue. On the other hand the contactor was designed for cars, not airplanes--so who knows what they considered.



 	  Quote: 	
		   

"Everything you've learned in school as "obvious" becomes less and less 

obvious as you begin to study the universe. For example, there are no 

solids in the universe. There's not even a suggestion of a solid. There 

are no absolute continuums. There are no surfaces. There are no straight 

lines." 

- R. Buckminster Fuller 	


 

Bob . . .

 	  Quote: 	
		  Interesting quotation . . . I'm fond of quotations 

that offer simple-ideas of easily discovered utility. 

How would you propose we use the learned gentleman's 

to guide our deliberations? 

 	




Bob, I like this quotation because Fuller suggests casting out "learned" assumptions and looking at problems without preconceptions. This is more philosophical than practical of course, but I like the idea that what we should begin by assuming everything we know is wrong.

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_________________
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net

N6030X(at)DaveMorris.com
Guest

Posted: Tue Oct 03, 2006 1:08 pm Post subject: Relays 'G's" skunk stink

At 03:37 PM 10/3/2006, you wrote:



 	  Quote: 	
		  Bob, I like this quotation because Fuller suggests casting out 

"learned" assumptions and looking at problems without 

preconceptions. This is more philosophical than practical of course, 

but I like the idea that what we should begin by assuming everything 

we know is wrong.


	


Or at least more complicated than we were first taught.  For instance 

in that Physics 101 class when the teacher (foolishly) said "assume 

this is done in a vacuum and there is no drag".  Then you find out 

the earth is not a perfect sphere, the adiabatic lapse rate is not 

uniform, electrons do not flow from positive to negative, and so 

on.  It's really depressing 

Dave Morris

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nuckollsr(at)cox.net
Guest

Posted: Tue Oct 03, 2006 6:01 pm Post subject: Relays 'G's" skunk stink

At 01:37 PM 10/3/2006 -0700, you wrote:



 	  Quote: 	
		  



Eric said:




	


   <snip>



 	  Quote: 	
		   > So the manufacturer says, "mount plunger vertical, cap down". I checked

 > into the engineering data on this part and of course the corporate

 > conglomeratization has destroyed the engineering knowledge that built the

 > part. The manufacturer PROMISED they'd get back to me.....It's not 

 DO-160 bubela. And it's only 122 deg F max operating temp. Etc. etc.

Bob replied:

 > Why would you suppose they would make this recommendation? Is the 

 engineering knowledge behind the recommendation so esoteric that we 

 cannot deduce it for ourselves?

I assume we can figure it out. My analysis is that the type-70 contactor 

has poor water-tightness (especially around the electrical terminals). 

This is a bit less of a problem with the cap down.


	


     Agreed



 	  Quote: 	
		    Also, when energized the plunger contacts an iron stop that is part of 

 the magnetic circuit when closed. There is no room in the space and the 

 plunger MUST be allowed to contact the stop or the coil will draw 

 excessive current, etc.


	


    Plunger position or even the presence of a plunger

    does not influence static coil current.

 	  Quote: 	
		  --The cap-down orientation prevents accumulation of debris in the 

plunger-stop space. So my vote is that gravity is the lesser issue. On the 

other hand the contactor was designed for cars, not airplanes--so who 

knows what they considered.


	


    Having disassembled more than a dozen of these

    devices over the years, I think we can make a pretty

    good guess. The springs are not real strong so the

    force of gravity would add a significant aiding

    or opposing force depending on orientation. This

    wouldn't be much of a concern for getting the critter

    closed . . . but contact spreading velocity would

    probably see a larger delta due to orientation than

    for decay rates of the magnetic field in the coil.

    I'll see if I can figure out a way to go measure that

    sometime. Also, the bore of the coil bobbin is plastic.

    More than one solenoid has become erratic due to

    erosion of bobbin interior due to a horizontal

    sliding core.



    In the case of contact spreading velocity for improved

    contact life, cap-down helps. For bobbin erosion,

    either vertical orientation would be okay.  It MIGHT

    be that they considered moisture effects . . . it's

    NOT a sealed relay and a non-sealed housing hit with

    cool splash WILL suck in water. Better that it's

    pooled in the cap than allowed to drip down over

    contacts, spring and plunger.



    If we were using these devices in an industrial

    control situation with hundreds of operations per day

    (with expectation for achieving a HIGH percentage

    of rated life), then religious observance of orientation

    cap-down would probably yield an increase in service life.



    Given that these devices in light aircraft operate perhaps

    a couple hundred times per year (and at loads much

    lighter than rated) the probability is that most

    of us will experience a maintenance event on these

    contactors due to environmental effects as opposed to

    wearing effects.



 	  Quote: 	
		   >

 > "Everything you've learned in school as "obvious" becomes less and less

 > obvious as you begin to study the universe. For example, there are no

 > solids in the universe. There's not even a suggestion of a solid. There

 > are no absolute continuums. There are no surfaces. There are no straight

 > lines."

 > - R. Buckminster Fuller

Bob . . .



 > Interesting quotation . . . I'm fond of quotations

 > that offer simple-ideas of easily discovered utility.

 > How would you propose we use the learned gentleman's

 > to guide our deliberations?

 >

Bob, I like this quotation because Fuller suggests casting out "learned" 

assumptions and looking at problems without preconceptions. This is more 

philosophical than practical of course, but I like the idea that what we 

should begin by assuming everything we know is wrong.


	


    Agreed . . . and according to some demonstrably practical

    folks like Dr. Virgil Elings, one should always proceed

    forward with a fine attunement to actions that are not

    helping or even worse, going in the wrong direction.



    I made his one-sided and limited acquaintance when a reader

    pointed me to this interview of Dr. Elings at:



http://webcast.ucsd.edu:8080/ramgen/UCSD_TV/11762.rm



    the audio on this presentation was pretty poor. I've

    done some post processing on it and placed a temporary

    copy at:



http://www.aeroelectric.com/Temp/Virgil_Elings-Look_at_the_Big_Picture.mp3



    I believe both Fuller and Elings would agree that

    one of mankind's biggest impediments to progress

    is the blind acceptance of preconceptions coupled

    with equally blind obedience to those who would hand

    out pre-conceptions be they in the form of bad

    science or bad plans.



    There is risk that some folks grab onto an idea

    like the Fuller quotation with a liberal

    dose of fundamental attribution error. Like:

    "Nothing is real, nothing is what it seems to be.

    Everything is irrelevant. Everything I do is

    irrelevant. I am irrelevant. Mr. Fuller said so."



    That's why I gravitate more toward folks like

    Kettering, Kelvin, and most recently Elings.

    Their ideas don't take much interpretation.

    They really jump out at you. They encourage

    healthy skepticism and stand up well to the

    repeatable experiment.



    Bob . . .

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glcasey(at)adelphia.net
Guest

Posted: Wed Oct 04, 2006 4:26 am Post subject: Relays 'G's" skunk stink

I have a suggestion for the reasons a manufacturer wants the relay  

mounted in a certain orientation, based on experience doing similar  

things.  It has mostly to do with water:  Generally, you want to  

mount the part in a way that water has the least chance of getting  

inside, so the cap is made like a roof so the water runs off.  Also,  

you want to have the internals arranged in a way that a drop of water  

inside has the least chance of causing a corrosion failure.  That  

might be to have the electrical connections to the coil at the top -  

or the contacts could be at the top if they are more vulnerable.   

Reasons like this make far more sense than G-load resistance.



Gary Casey

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Eric M. Jones

Joined: 10 Jan 2006
Posts: 565
Location: Massachusetts

Posted: Wed Oct 04, 2006 11:02 am Post subject: Re: Relays 'G's

Bob said: 

 	  Quote: 	
		  Plunger position or even the presence of a plunger 

does not influence static coil current. 	




Oops...Yes you are right...



Re: Fuller Quote--



At least I have refrained from using as a signature:



"Concepts of space and time are certainly doomed." Dr. Edward Witten

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_________________
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net

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