Miller Electric

Welding Discussion Forums

Home » Resources » Communities » Welding Discussion Forums
 
Miller Welding Discussion Forums - Powered by vBulletin

Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 25
  1. #11
    Join Date
    Feb 2009
    Posts
    3

    Default Hi frequency mitigation

    Weldbay, Thanks for sharing those articales, they are right to the point. I would guess there suggestion that in addition to connecting the ground rod to the welding machine framework and the welding table, the disconnect and outlet where the welder is connected should also have their grounds connected directly to the grounding rod. Is that your understanding? Berol

  2. #12
    Join Date
    Oct 2004
    Location
    Edmonton, Alberta
    Posts
    7,731

    Default

    I am not sure what WTF means but I will assume you respect this forums rules.

    Means What the fredrick,
    anyhow, I've only been repairing welders and associated problems for 20 years. and have the respect from other techs, and run a warranty service center for all brands. I'm heavily factory trained don't have to explain any theory to you.

    The best way to eliminate HF interference is the run a separate ground back to the main breaker.

    Say if the ground is high in moisture, pounding a ground rod into it may agravate the situation.

    But giver

  3. #13
    Join Date
    Nov 2006
    Location
    Lake of the Ozarks MO
    Posts
    3,558

    Default

    The way Cruizer says is well known....I have heard it said from other sources as well. I have never heard Cruizer steer anyone in the wrong direction.
    From my own exp. I own a PORTABLE aluminum welding rig and I haven't had to drive a ground rod yet!
    As for the tie wrapping the leads together.....that is what my dads pacemaker mfg's rep suggested to me. (actually I believe they suggested wrapping them for a good bit) Good enuff for me.
    I prefer SBerry's ealier suggestion best tho. Simply run it and see what happens.
    Older machines were way worse than newer inverter style Dynasty's etc.
    The only thing I have on my shop machines is good wiring. No ground rods dedicated simply to any one machine. Everything works perfect for me.
    I live in my shop and have tv's, computers etc, everywhere including IN the shop.
    If your gap is set wide, I believe the problem worsens btw. I also realize some people DO suffer with problems so YMMV.
    HTH, Garry

    www.facebook.com/outbackaluminumwelding
    Miller Dynasty 700...OH YEA BABY!!
    MM 350P...PULSE SPRAYIN' MONSTER
    Miller Dynasty 200 DX "Blue Lightning"

    Miller Bobcat 225 NT (what I began my present Biz with!)
    Miller 30-A Spoolgun
    Miller WC-115-A
    Miller Spectrum 300
    Miller 225 Thunderbolt (my first machine bought new 1980)
    SPEEDGLAS 9100XX

  4. #14
    Join Date
    Dec 2011
    Posts
    392

    Default Theory anyone?

    Quote Originally Posted by weldbay View Post
    What leads, the ground and the torch? Hf will bleed you are right but you need the HF in the Tung to initate the arc what you are suggesting would reduce the intensity and the amount of HF at the weld. I have seen Hf reduced just by leaving your 25 torch partially wound up on your cable holder and not stretched out as it should be.
    You are talking about two very different animals here. When you wind your torch lead into a coil you have for all practical purposes created a choke coil(inductor) which will indeed impede the AC on the cable. As well it will shift the AC current out of phase with the AC voltage. I don't know the practical result of the latter but I'm thinking it is not particularly good.
    When the leads are taped together the situation more closely represents a twisted pair which will help to equalize the inductance and capacitance along the length of the cable which should stabilize the AC portion of the arc. In addition if anyone ever bothered to read the EMF information in their manual they would discover that twisting or taping the leads together is one of the recommendations listed there.
    Stay safe-Meltedmetal

  5. #15
    Join Date
    Nov 2012
    Location
    Washinton
    Posts
    56

    Default

    EMF is regulated and yes twisting, or tapeing cables will assist in controling the EMF. However it is hard for me to understand, theory, that will intensify the HF at the arc or that is will create a more stable arc, especially in an old transformer mach. As for grounding the Hf feedback put the rod in the ground, do not put it on your cold water pipe, you bleed current into the pipe and it will cause electrolysis and eat your pipe. If you have a pacemaker don't tig weld.

    I am willing to learn so please explain.

  6. #16
    Join Date
    Oct 2004
    Location
    Edmonton, Alberta
    Posts
    7,731

    Default

    EMF is regulated and yes twisting, or tapeing cables will assist in controling the EMF. However it is hard for me to understand, theory, that will intensify the HF at the arc or that is will create a more stable arc, especially in an old transformer mach. As for grounding the Hf feedback put the rod in the ground, do not put it on your cold water pipe, you bleed current into the pipe and it will cause electrolysis and eat your pipe. If you have a pacemaker don't tig weld.

    Really there is extremely little amperage (next to zero) with HF alone, its just super high voltage.

    Are you a Tech Weld Bay?

  7. #17
    Join Date
    Nov 2012
    Location
    Washinton
    Posts
    56

    Default

    I am not sure what you are refering to, am a a tech yes, do I know everything no.

    Grounding electrical circuits, lke when you ground your washer, your welder or any electrical product will create electrolysis in copper pipe carrying water.

    Ground rods are simply the right way to ground a circuit, and if fact in most modern const, an earth ground is common.

    HF runs about 10,000 volts at almost no amps, it has a tendency to follow the path of least resistance in weld cable, runs more along the outside of the copper than the inside keeping resistance down and amps down.


    HF had a tendency to bleed into other circuit and causes frequency interference with radio signals, computors and cell phones., by grounding the circuit you substanilly reduce the amount of bleed and thus the affect of HF on surrounding electrical products.

    As for EMF and it's effect on the welding arc and the HF intensity I believe that tapeing or twisting the cables together will reduce the HF intensity and little if any affect on the arc. They actually use a switching EMF to move the arc back and forth in some weld applications.

    That said it is just my opinion based on what I beleive I know, if is is not right then correct that which I misunderstand, I will learn if not admit you are wrong and we can move on.

  8. #18
    Join Date
    Dec 2011
    Posts
    392

    Default

    Quote Originally Posted by weldbay View Post
    EMF is regulated and yes twisting, or tapeing cables will assist in controling the EMF. However it is hard for me to understand, theory, that will intensify the HF at the arc or that is will create a more stable arc, especially in an old transformer mach. As for grounding the Hf feedback put the rod in the ground, do not put it on your cold water pipe, you bleed current into the pipe and it will cause electrolysis and eat your pipe. If you have a pacemaker don't tig weld.

    I am willing to learn so please explain.
    Disclaimer: I am not a welding equipment design engineer and it would be nice if they would chime in and give us the official verdict but never the less I'll give you my view and you can consider it.

    There are no magic arc multipliers that create energy from nothing. What we are considering here is the intensity of arc at the end of an infinitely short set of cables versus the arc at the end of the real world cables. Anything that reduces losses in the system will "intensify" the arc closer to it's maximum. You could think of your cables as transmission lines as a long series of inductors and capacitors. The inductive reactance component shifts the phase relationship between the voltage and the current causing the current to lag the voltage(power factor). Close coupling the cables increases the capacitive reactance shifting the power factor back closer to the ideal of 1. As you are likely aware as your power factor deviates from 1 in either direction (that is: current leading or lagging voltage) the effective power in the system is reduced and this imbalance I believe would create instability in the arc. The correction as much as is possible in a real world system should deliver a more stable arc.
    As to whether or not the type of supply would make a difference(transformer or inverter) if we consider a nearly identical supplied wave I don't see why the supply should make a difference. If we were to use an inverter that could deliver customized waveforms well could be a whole new ball game but still doesn't negate the principal.
    With regard to grounding, I quite agree that a known ground is preferable to an unknown one. With the common use today of non-conductive plumbing these days it might not be advisable to use the plumbing on that count alone as you can not always be sure you are electrically connected where you expect to be.
    You might also want to consider connecting your "ground rod field" to your service ground for lightning protection. In my opinion an exterior to the building conductor is preferable. If you were to have a near lightning strike it could cause a substantial potential to arise on one of your ground systems but not simultaneously on the other. Significant current could then flow through your ground system in search of dissipation. This can result in dangerous voltages on anything that is grounded in your building until it finds the other ground and dissipates. It could damage equipment or you. Hope I'm not too far off the mark here and it makes some kind of sense.
    Meltedmetal

  9. #19
    Join Date
    Nov 2012
    Location
    Washinton
    Posts
    56

    Default

    Thank you for your response. In trying to understand, if I tape or twist my cables together closer to the source or nearer the lugs, would you not create a point where the HF might not bleed into the line at that point. If it did would it not decrease the intensity at the torch end. And I am not sure how decreaseing the EMF would assist an AC arc, and would have a neagative affect on a DC arc.

    If this is getting beyond the purpose of the Post then please contact me at admin@weldbay.com. I would really like to understand.

  10. #20
    Join Date
    Oct 2004
    Location
    Edmonton, Alberta
    Posts
    7,731

    Default

    Quote Originally Posted by weldbay View Post
    Thank you for your response. In trying to understand, if I tape or twist my cables together closer to the source or nearer the lugs, would you not create a point where the HF might not bleed into the line at that point. If it did would it not decrease the intensity at the torch end. And I am not sure how decreaseing the EMF would assist an AC arc, and would have a neagative affect on a DC arc.

    If this is getting beyond the purpose of the Post then please contact me at admin@weldbay.com. I would really like to understand.
    You the first person who questioned its validity, without trying it, as for DC tig, it doesn't really matter as the HF is only there until your arc is established, so 1/2 second maybe. Basically the taping is not needed on inverter machines as once the arc is established the hf turns off and the arc is maintained through the inverter.

    Only on transformer machines, its required to limit the amount of HF going everywhere searching for the torch. Taping the work and torch together focuses the hf with the final arc. It works suprisingly well. And stops the Radio from buzzing, garage doors going up and down, ect, ect....

    It's not nessesary to wrap your head around it. If you have a customer thats having troubles, quickily tell him what to do, and you won't have anymore phone calls from him. Simple as that,,, Again not getting into the very simple theory behind it.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Warning: Non-static method PhpQuickProfiler::getMicroTime() should not be called statically in /mnt/stor3-wc1-dfw1/357822/357839/www.millerwelds.com/web/content/lib/pqp/classes/Console.php on line 77

Warning: Non-static method PhpQuickProfiler::getMicroTime() should not be called statically in /mnt/stor3-wc1-dfw1/357822/357839/www.millerwelds.com/web/content/lib/pqp/classes/Console.php on line 77

Warning: Non-static method PhpQuickProfiler::getMicroTime() should not be called statically in /mnt/stor3-wc1-dfw1/357822/357839/www.millerwelds.com/web/content/lib/pqp/classes/Console.php on line 77

Warning: Non-static method PhpQuickProfiler::getMicroTime() should not be called statically in /mnt/stor3-wc1-dfw1/357822/357839/www.millerwelds.com/web/content/lib/pqp/classes/Console.php on line 77

Warning: Non-static method PhpQuickProfiler::getMicroTime() should not be called statically in /mnt/stor3-wc1-dfw1/357822/357839/www.millerwelds.com/web/content/lib/pqp/classes/Console.php on line 77

Warning: Non-static method PhpQuickProfiler::getMicroTime() should not be called statically in /mnt/stor3-wc1-dfw1/357822/357839/www.millerwelds.com/web/content/lib/pqp/classes/Console.php on line 77

Warning: Non-static method PhpQuickProfiler::getMicroTime() should not be called statically in /mnt/stor3-wc1-dfw1/357822/357839/www.millerwelds.com/web/content/lib/pqp/classes/Console.php on line 77

Warning: Function split() is deprecated in /mnt/stor3-wc1-dfw1/357822/357839/www.millerwelds.com/web/content/lib/footer.inc.php on line 82

Welding Projects

Special Offers: See the latest Miller deals and promotions.