AC SMAW on an inverter power source question

[Helios]

Excuse me? Did I say "kill"? No, I said "electrocute". You know there's a difference, right? People are electrocuted every day without dying. Lots of people.

Really?

electrocute

1. to execute (a criminal) by electricity

2. to kill by electric shock

Looks to me like everyone who's ever been electrocuted is deader than a doornail.

[GilaSlim]

If you die, you have been electrocuted. If you don't die, you have been shocked. Helios' definition is correct. I have been shocked more than once, but fortunately never electroctued.

Yes, AC is more dangerous than DC. At 60 Hz, AC frequency is similar to the frequency of the electric pulses that control the heart, and can interfere with it. Edison, in his fight against AC would electrocute (kill) elephants in public spectacles to prove his point. Over 130 years of experience has proven that AC can be used safely, if handled properly. Miller's warnings are appropriate, and necessary for those lacking experience with AC.

Matrix, nobody is "taking a crap" on you just because you are new. The problem is you display an argumentative attitude, you are always right, and you get whiny when anyone disagrees with you.

Cruizer is a recognized, well respected expert on this board. We are lucky to have him here. Yes, he can sometimes be abrupt in his responses, but he does not "take a crap" on new guys.

Suck it up, dude. Don't be so sensitive. Recognize that people will sometimes disagree with you.

[Matrix]

When someone takes your comment out of context and then tries to make it look like you said something you did not say so that they can create an argument ... that is not disgreeing with an opinion. That is called picking a fight. Don't think for a second that I don't know the difference.

My apology for my misuse of the word electrocute.

That apology does not change the fact that AC welding is more dangerous than DC welding and it also does not change the fact that there never should have been a debate on it in the first place because only a fool would argue that AC welding is as safe as DC welding, especially when you steer the conversation away from the original context. (SMAW vs SAW) Except for my unfortunate misuse of the word electrocute there was nothing in my comment that anyone should have taken exception to enough to start an argument over.

As for my being argumentative, well I see it another way. I see how two people in the last week have been argumentative with me first. I didn't start either fight. You can call that a difference of opinion if you like. I prefer to call it what it is.

[Arizona Joe]

...AC welding is more dangerous than DC welding...

Matrix, after thinking about this, I believe you are correct! (The emphases are mine.) This is specific to welding. However, in general, I do not believe that AC is more dangerous than DC. And as for Edison's demonstration, it was pure rubbish. DC would've worked just as well.

http://en.wikipedia.org/wiki/Topsy_(elephant)

"Topsy was fed carrots laced with 460 grams of potassium cyanide before the deadly current from a 6,600-volt AC source was sent coursing through her body, partly as a demonstration of how "unsafe" his competitor's (Nikola Tesla) alternating current design was."

Now, getting back to welding, there is a stinger and a work clamp, sometimes, erroneously called a ground clamp. One is the source, and the other is the return. Every circuit needs a source and a return. A ground is a source of zero potential. It is not necessarily a return, although it can be.

In DCEP, the stinger is the source and the work clamp is the return which is at zero potential. If you are standing barefoot in a steel bucket of salt water resting on a steel floor and grab the stinger you will probably get a shock. If, on the other hand you grab the work clamp you will not a get a shock.

Now, on an AC welder, like a transformer buzz box, the roles of the stinger and work clamp change from source to return and return and source 60 times a second. So, the work clamp as well as the stinger are both hot all the time. Now when you stand in the water you will probably get a shock if you touch either the stinger or the work clamp.

I've been a welder for two whole months now While far from being an expert still, this is the way I think it works. So, guys and gals, have at it. I'm here to learn.

[paulrbrown]

Well Weldors: I do not have the numbers in front of me, but in the past, I read somewhere that it takes one heck of a lot less AC to stop your heart as it does DC. I will try and find, but I am thinking it is 1/100 or 1/1000 less.....bear with me while I research......hope this helps.....and yes, I have tried welding SMAW with AC on my 200DX, I have even pulse welded SMAW with my SynchroWave 250, but that was DCEP.....kinda kool too.....hope this helps.....Matrix, you will find some smarty pants folks here, but most are quite Humble, I joined in 03, even though it does not show it....a format change ended up giving me a later join date....Cruizer is a good guy....and yes, sometimes abrupt.....but still a good guy, Welcome to the Forum.....Hope this Helps, and I am researching that voltage info now....Paul

[paulrbrown]

OK Weldors, I just found the info I was looking for, I was wrong on the percentages, AC is 3 to 4 times more likely to kill as DC, here is a link to a good read...and I sure hope this helps someone.....Paul

http://www.avotraining.com/common/documents/avotraining/The%20Hazards%20of%20Electricity%20-%20Do%20You%20Know%20What%20They%20Are.pdf

[Matrix]

changed my mind

[paulrbrown]

changed my mind

Great to hear Matrix, you look like you will be an asset to the Forum.

Hope the info I posted helps...Paul

[Arizona Joe]

Thanks for link - I learned something

OK Weldors, I just found the info I was looking for, I was wrong on the percentages, AC is 3 to 4 times more likely to kill as DC, here is a link to a good read...and I sure hope this helps someone.....Paul

http://www.avotraining.com/common/do...They%20Are.pdf

Quite a few years ago, in regard to the NYC subway where the third rail is about 400 VDC, I asked a professor of electrical engineering about the real dangers of getting electrocuted, hypothetically of course, over 400 VAC. He wasn't sure. He said perhaps the zero crossings of AC may give you a better chance of surviving, but he didn't know. And so, I never really knew. And if you do a search the answers are all over the place. So, finally, I have a good answer. So Paul, thank you very much!

[paulrbrown]

Quite a few years ago, in regard to the NYC subway where the third rail is about 400 VDC, I asked a professor of electrical engineering about the real dangers of getting electrocuted, hypothetically of course, over 400 VAC. He wasn't sure. He said perhaps the zero crossings of AC may give you a better chance of surviving, but he didn't know. And so, I never really knew. And if you do a search the answers are all over the place. So, finally, I have a good answer. So Paul, thank you very much!

AZJoe, you are quite welcome, the other day I was doing some electrolytic rust removal, battery charger with negative lead connected to part and an anode with positive lead placed in bucket of water with baking soda. 12V 2 amp charge rate, well, I learned not to touch both at the same time......now me and Don King have something in common.......

[gnforge]

AC SMAW on an inverter power source question

Lol. !! Story of my life, been doing this off & on for 35 years. Back to full time. And just burnt my hand for the millionth time tacking up a piece.
I'm to old & stubborn now to learn any better.
Thx for the laugh, glad to know I'm not alone.
:-)

[paulrbrown]

gnforge, ever notice if you have a hole in your glove....you do wear gloves???? that is where the hot part always seems to be when you pick something up..... Mom said don't touch that stove, but did we listen, no, we bacame weldors....and we like it.........

[gnforge]

AC SMAW on an inverter power source question

Yep. Wear gloves, did the hole in the glove trick two weeks ago. Had it taped, ha ha know better, nice round red hot ball found it's way in and sat on my cuticle, needless to say with moves like a Ninja it wasn't quick enough, left a black crater!!
This time I even had my trusty Miller gloves on & blistered my thumb through the glove. Hay maybe I should ck the Limited Warranty on gloves wonder if it's covered. ?? Maybe not, like ma ma always said. Ya just can't fix stupid. Good thing the Lord created us to heal or I'd been gone long time ago.
Take care Greg

[johnsnowkornar]

Exactly. Out of curiosity I decided to take a peek in the owners manual on my Dynasty 200DX, which just happens to be the exact topic of discussion in this thread if anyone cares to remember.

On the very first page in section 1-2 under the heading "Arc Welding Hazards" are warnings on of the dangers of selecting AC output welding current.

And I quote:

- Wear dry, hole free insulating gloves and body protection
- Insulate yourself from work and ground using dry insulating the cooling mats big enough to prevent physical contact with the work or ground.
- Do not use AC output in damp areas, if movement is confined or if there is a danger of falling.
- Use AC output ONLY if required by the process.

(In large bold letters)
ELECTRIC SHOCK can kill.
With symbols depicting a weldor touching the end of the electrode and electric current running through the man's body.

Sure sounds to me like Miller thinks maybe there are a few safety concerns with AC welding. They tell you to take measures to prevent contact with the work or the ground and they show you a picture of a man touching the electrode and being electrocuted but never mind any of that, Cruiser knows best and it doesn't matter anyway because we take a crap all over the new people here whether they are right or wrong.

What's more, for what reason would we say we are contending about this, precisely? How is this significant to the first question?

[lars66]

Yes, the fellas running a weld from a basic Transformer from other countries is just that, they are not using an actual welder, instead they are using a stepdown non regulated and non grounded transformer pulled out of a scrap heap, which generally is directly tied into another unregulated power off a supply line. No breakers or saftey to speak of.

I on the other hand was talking about an actual regulated brand of AC welding machine which it would be tough to kill yourself with.

Well I had a AO Smith AC bee hive welder that just about laid me out twice in one day when changing rods. Was so hot and humid the sweat was pouring off me and even the concrete floor was sweating. And yes I was wearing gloves.