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Up Topic Welding Industry / Technical Discussions / Grounding metal objects near weld equipment reasons
- - By JEEPS Date 06-06-2007 00:52
I read that all metal objects like tables and racking should be grouded to earth with in a certain distance (i think it is 50 feet) of high frequency welding. I am curious as to what this prevents. I understand that the work lead is not a ground. I haven't been able to get any info on the reason for this, just that it should be done.

Thanks for any info,
Brian
Parent - By DaveBoyer (*****) Date 06-06-2007 02:52
High Frequency is actually a radio wave. It can be transmitted from the cables and work. Running the primary feeds through GROUNDED metal conduit, grounding the machine cabinet, and grounding any sizable chunks of metal near the welding area tends to absorb the radiated wave energy and bleed it off to ground so it causes the least interfirence with electronic equiptment.
Parent - - By bozaktwo1 (***) Date 06-06-2007 16:41
Side note: if you like your digital watch, mp3 player, pda or cell phone to work then keep them a good distance from high-freq welding equipment.  Bad experiences speaking there.
Parent - - By Tommyjoking (****) Date 06-07-2007 07:47
drawing on my old electronics background..."cough cough cough" " lots of cobwebs back here"

The only reason I can think of as far as "welding with High Frequency"   is 1. magnitization of any metal object  2.  a light induced static charge.   ANY ferrous metal object subject to long exposure to high frequency will become slightly magnetic...  the magnitisim comes from electromagnetic activity from an induced charge.    If you are working in a bomb factory or amunition plant I would take it VERY seriously...in a weld shop...its a dust catcher.

Any time you pass electrical current through a conductor you WILL generate a magnetic field.  The stronger the current the stronger the field.  However in ferrous metals that magnetic field can take up a temporary residence over prolonged exosure.  Now what happens when you pass a conductor thru a magnetic field...it generates electricity or voltage in that conductor....if that conductor leads to earth or ground then you will have current,  So there is potential for a spark or an arc in ferrous metals exposed to high frequency ...no matter how unlikely there is a chance.

If you are passing radio waves (high freq) signals thru a metal you are causing electrons to bump into each other....you may move some in the metal and cause a charge to build up as well as residual magnitism.....if they are grounded to earth ground....this cannot occur.

Enough exposure to this can cause electronics to go haywire, cd players change track, radios lose thier programming, watches cease to work, mp3 players shut off for no reason  etc etc.

Jeez what is it doing to our bodies and brains????!!!!

I hope that was a good explanation and I did not sound all pompous and stuff ....I hate that.

Tommy
Parent - By DaveBoyer (*****) Date 06-08-2007 03:24
Because the HF is in the radio frequency range it can cause interfirence on voice/data frequencies. The grounding bleeds off the HF so it isn't transmitted efficiently. If You transmit a strong enough signal and happen to be interfering with legitamet brodcasting the FCC will shut You down.
Up Topic Welding Industry / Technical Discussions / Grounding metal objects near weld equipment reasons

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