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Anonymous Poster #1

Holm's or Blow-Off Force Calculation

09/05/2012 6:55 AM

How to calculate Blow-off force in the electrical contact joint for certain current. i have one flat surface and one round surface of 10mm diameter, touching each other. i want to calculate repulsion force between these two conducts of 30kA current.

Can any one help?
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TonyS
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#1

Re: Holm's or Blow-off force claculatation

09/05/2012 7:50 AM

Homework?

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Joshi
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#2

Re: Holm's or Blow-off force calculation

09/05/2012 8:00 AM

How is the repulsive force generated? In what electrical equipment, do you have a flat surface and one round surface of 10mm diameter, touching each other? Are these two surface powered, if so by what & how much? Could you post a schematic/sketch?
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lyn
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#3

Re: Holm's or Blow-Off Force Calculation

09/05/2012 9:37 AM

I make it out to be 3x10-4 millihenweighs.
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Joshi
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#4
In reply to #3

Re: Holm's or Blow-Off Force Calculation

09/05/2012 9:45 AM

I think you are right, Lyn.
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Doorman
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#5
In reply to #3

Re: Holm's or Blow-Off Force Calculation

09/05/2012 10:25 AM

"3x10-4 millihenweighs."

Okay, I get milli- is a factor of one thousandth... but.. wot's a henweigh?

Doorman takes full credit for being the straight man!

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Joshi
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#6
In reply to #5

Re: Holm's or Blow-Off Force Calculation

09/05/2012 10:52 AM

Copyrighted! To know that, you have to buy a copy of "Lynencyclopedia"
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Doorman
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#7
In reply to #6

Re: Holm's or Blow-Off Force Calculation

09/05/2012 11:16 AM

Lynencyclopedia

Oh, Joshi, I knew you would fit in well around here!

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Joshi
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#8
In reply to #7

Re: Holm's or Blow-Off Force Calculation

09/05/2012 11:27 AM

Thank you. Life is short. Let us LIVE it when it lasts.
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lyn
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#9
In reply to #5

Re: Holm's or Blow-Off Force Calculation

09/05/2012 11:28 AM

Oh, bout 3-4 pounds.

Kinda lost its luster after being upstaged by that upstart Joshi.

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Joshi
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#10
In reply to #9

Re: Holm's or Blow-Off Force Calculation

09/05/2012 11:32 AM

Have a good day, Lyn.
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kvsridhar
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#11

Re: Holm's or Blow-Off Force Calculation

09/05/2012 2:47 PM

Holds good for spherical-on-flat contact also.

Considers only "crowd-effect" repulsion at contact point. Any additional repulsion forces due to bent-back contacts, slot motors, etc not part of this calculation.

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Joshi
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#12
In reply to #11

Re: Holm's or Blow-Off Force Calculation

09/05/2012 3:53 PM

This, surely is the best one. Welcome aboard.
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lyn
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#13
In reply to #11

Re: Holm's or Blow-Off Force Calculation

09/05/2012 3:55 PM

Am I just not observant, or have you recently moved?

Cheers.
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Joshi
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#14
In reply to #13

Re: Holm's or Blow-Off Force Calculation

09/05/2012 4:06 PM

I am sorry, Sir.

In future, I shall stand behind you & take my turn in the queue.

It's a promise.
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lyn
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#15
In reply to #14

Re: Holm's or Blow-Off Force Calculation

09/05/2012 4:27 PM

No, no. Please feel free to jump in any time.

The (very intelligent) gentleman to whom I directed my query used to reside in India.

(And, best of all, he's a beer drinker)
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kvsridhar
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#16
In reply to #13

Re: Holm's or Blow-Off Force Calculation

09/05/2012 5:58 PM

You are observant for sure. i am visiting my son who lives in Ashburn. Mainly to see firsthand my new granddaughter !!!

Alas, too soon i will be returning to Bangalore ....

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lyn
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#17
In reply to #16

Re: Holm's or Blow-Off Force Calculation

09/05/2012 6:55 PM

Cute kid! She must have a pretty mother and a handsome grandfather.

Enjoy your stay here, and the grandbaby!

Via con dios
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kvsridhar
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#19
In reply to #17

Re: Holm's or Blow-Off Force Calculation

09/06/2012 6:47 AM

A pretty mother and a not-too-bad-looking father i dare say, though my wife and all my cousins thrice removed claim some resemblance !

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pnaban
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#18
In reply to #11

Re: Holm's or Blow-Off Force Calculation

09/05/2012 11:42 PM

May I know your source(book,website,catalogue etc) of this information.

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kvsridhar
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#20
In reply to #18

Re: Holm's or Blow-Off Force Calculation

09/06/2012 7:05 AM

ECT162 from Schneider Electric.

Also a paper from a Czech research lab whose website does not seem to exist any more.

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Users who posted comments:

Doorman (2); Joshi (7); kvsridhar (4); lyn (5); pnaban (1); TonyS (1)

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