Braided Cables - EMI C/M or Internet Tripe?

After about 40 yrs of competitive distance running, the doctors say my heart rate has gotten too low. They are recommending I receive a pacemaker. Yes, you can exercise your way into a heart abnormality :grimacing:

I started reading on the “pacemaker vs cutting/welding equipment” topic expecting the worst. Looks like 10-15 yrs ago, the advice was 100% against welding after install. Now, there are circumstances where it is okay, within limitations. Not going into that because I don’t want to get bashed for doling out internet medical advice. Suffice to say, my case is one where I may be able to continue to use my equipment.

To the point. I know on this site the EMI countermeasures I’ve seem discussed for cutter vs controller are: increased distance; no coiling of cables; computer electrical isolation. All pretty easy to see potential benefits.

During my reading, two different welding threads I saw recommendation to braid the work and electrode leads over as much of their length as possible. Assuming interference-based cancellation is the goal, I don’t know enough about the frequency and waveform shapes of plasma cutter and welder outputs to know if this seems like a potential EMI reduction strategy or not.

Anyone with knowledge they want to share us in on this idea? Should we add this approach to the advice given when people are having EMI issues with their LS equipment?

Here is a document where Hypertherm explores the EMI effects on people for one of the plasma cutting products.

file:///C:/Users/canad/Downloads/HPR260XD_EMF_Datasheet%20(2).pdf

here is some of the recommends for personal EMI protection from this.

“How Do I Minimize EMF Exposure?
Failure to follow these instructions will increase EMF:
 cut with the lowest current setting necessary for the application and quality of the cut.
 never coil a torch cable or work lead around your body.
 do not place your body between the torch cable and work lead.
 route cables together on the same side of your body.
 route the torch cable and work lead close together. if possible, secure them together with tape or cable ties.
 connect the work cable to the workpiece as close to the cutting zone as practical.
 keep the cutting power source and cables as far away from you as practical.”

I had link a larger document about this in the past but i cant find it now.

Here is a clip from Hypertherm safety manual

file:///C:/Users/canad/Downloads/OM_806690_R9_SafetyCompliance%20(1).pdf

And this document about minimizing the EMI at the machine has been posted a lot.

https://www.hypertherm.com/Download?fileId=HYP104686&zip=False

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Just took my mom in for a standard procedure a couple weeks ago. She came out a week later with a pacemaker!!

They also told her to say away from strong magnets… A friend in the medical field said they have a strong magnet they use to drain the batteries in pacemakers when the person is done with them.

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Guess this lends some credibility to the idea that braiding them might at least not be a bad idea.

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The idea is that those fields cancel each other out. If I use a clamp on amp meter and clamp over either the work lead or the electrode lead ( likely have to do this from the inside of the machine) I will get get a reading of -45amps of +45amp (=/- if cutting a 45amps). If I could clamp both the electrode lead and the work lead in the clamp on amp meter it would read nothing.
A clamp on amp meter works when a magnetic field created by current (amp) in the wire and meter reads this (probably through induced voltage like a transformer ) which is converted to a amperage reading. but with both wires in the clamp the fields cancel and read as zero on the meter.

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Thats what I was getting at in my original post when I mentioned “interference-based cancellation”. Thanks for the better detail. Makes sense.

I think I have enough work clamp cable that I can braid at least the first 5’ post cutter. I think I will just for the heck of it. Cheap insurance.

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I think its all hype. Now a tig welder I could believe. Who in their right mind wraps work or torch cables around thier body. Again I believe that some high frequency EMI does exsist it not dangerous in normal circumstances.
I know a pace maker was brought up.
Now that would be a different story.
An installed pace maker will put you out of the metal fab business. Period… I know you are looking for other answer.
A good friend of mine is a cardiologist and he says welding, microwaves or any other EMI emitting devices.

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