Author	[Modern View]
Stan in Oly, WA 02-25-2013 00:10:45 174.31.223.173 Report to Moderator	When I teach beginners to use any kind of arc welder, I explain that what we call the ground clamp should more accruately be called the work lead; that its purpose is to continue the circuit back to the work so that the circuit is completed and an arc is created when the electrode touches the work. I tell them that this is not a ground in the same sense that there is a ground in their home electrical system, and that they could not weld by running a ground wire from the electrical system to the workpiece instead of the work lead. I wanted to demonstrate this, but two things stopped me: 1. I wasn't absolutely sure I was right. I would have tried it at home first, except that... 2. buickanddeere gets really mad at people who use the neutral as a ground and jeopardize the safety of utility workers who may be injured by encountering current in a line where there shouldn't be any. What I realized was that I simply didn't know what would happen if I were to touch an electrode with, for instance, 78 volts OCV and 90 amps to a grounded workpiece. Even if it didn't weld, it might energize the ground. Would it? Stan [Reply]   [No Email]
David G 02-25-2013 08:44:24 205.215.206.18 Report to Moderator	Re: Ground for a welder in reply to Stan in Oly, WA, 02-25-2013 00:10:45   Dog stuck his nose on trailer once being welded. He let out a yelp and never came near trailer again.   [Reply]  [No Email]
JOB 02-25-2013 08:42:05 50.124.208.41 Report to Moderator	Re: Ground for a welder in reply to Stan in Oly, WA, 02-25-2013 00:10:45   Grounding question for an electrician. Below is posted a couple of welding incidents, situations or maybe mild accidents. I read an article in the newspaper maybe 30 years ago of a farmer and son working on a manure spreader. Son was welding and father working. I have assumed the welder was an AC buzz box because that was what most farmers had back then. The news paper article did not say what the welder was. There are a lot of electrically smart people on here so I will tell what I read to the best of my memory. The welder was grounded to the rusty tongue of the manure spreader The son was welding somewhere on the spreader. Don't know if he was standing on the ground (dirt) or on the spreader itself. The father was laying on the ground working on the bottom of the spreader. This was a really hot and humid day like when you can't even walk outside without sweating. While the son was welding the father was electrocuted. The newspaper article said the father made a better ground than the grounding clamp. Any electricians want to comment on this? This is just what I read in the newspaper second hand to the best of my memory.   [Reply]  [No Email]
John T 02-25-2013 13:55:04 71.52.99.130 Report to Moderator	Re: Ground for a welder in reply to JOB, 02-25-2013 08:42:05   Good post, I will try to explain it for you in simple terms so as to NOT loose you, here goes. If its an AC Buzz Box Welder its an isolation transformer and if theres no leaks or shorts the ONLY voltage difference is between the leads, stinger and the groung clamp, none with respect to mother earth or the concrete floor or structural building steel from either lead. Thats notwithstanding inductive and capacitance which can create some other potentials but those are low energy. Soooooooooo if one part of a farmers body is in contact with say the stinger or metal its in contact with and another part of the body is in contact with the ground clamp or metal or water or earth etc its in contact with THAT VOLTAGE CAN CAUSE A CURRENT FLOW and it only takes maybe 30 TO 50 milliamps across the ticker to cause it to de fibrillate and YOU DIE. If you put one hand on the stinger and another on the ground clamp theres a voltage difference and current can flow.......Same if youre lying on the wet ground or up againstg a metal farm implement etc that either the stinger or ground are contacting you can get shocked Got it??????? John T   [Reply]  [No Email]
JOB 02-25-2013 16:27:38 74.36.134.85 Report to Moderator	Re: Ground for a welder in reply to John T, 02-25-2013 13:55:04   Not entirely, I do not understand the weird things electricity can do. I had heard that it only takes a couple of milliamps across the ticker to put you into that eternal sleep. The post above this one from David G, his dog put his wet nose to a trailer that was being welded on, and it sounds like he got bit by something. Aboard ship when in an engine room and welding I would get a tingle when putting an electrode in the stinger if I was not wearing a dry glove and standing on a wet deck.   [Reply]  [No Email]
John T 02-25-2013 17:38:31 71.52.99.130 Report to Moderator	Re: Ground for a welder in reply to JOB, 02-25-2013 16:27:38   A GFCI is designed to trip around 5 milliamps and this is for an approximate safety factor of ten times. Typical figures Ive seen for defibrilation are 30 to 50 milliamps. Again the voltage output of a buzz box AC transformer welder is between/across its leads (stinger and ground NOT either lead to other AC wiring) but one or both of those leads are against metal or on concrete or wet mother earth and if your body gets between one or the other (or water or metal etc) you get shocked.. Electricity doesnt necessarily do weird things (from an engineers perspective), current simply tries to flow anytime theres a voltage difference and ohms law defines how much in whatever paths are available subject to the paths resistance. Hang in there, youre comin around John T   [Reply]  [No Email]
smallercrawler 02-25-2013 11:38:39 166.82.254.181 Report to Moderator	Re: Ground for a welder in reply to JOB, 02-25-2013 08:42:05   Early 70's, company decided to eliminate 4 overhead bridge crane operator jobs on a 2 bay/2 cranes per 600' bay installation. Bought a then "state of the art" AB digital processor/control system for ~$400k (analgous to elevator call/que scheme). Vendor took 3 months to install/debug system. Worked great until shutdown when another vendor was employed to do some mods. on the crane rails/supports. Poor welder grounding apparently fried the system; the electronics vendor was not responsible, welders went out of business. Company had to eat it. Just an example of what improper grounding can do.   [Reply]  [No Email]
JOB 02-25-2013 13:39:43 74.36.130.21 Report to Moderator	Re: Ground for a welder in reply to smallercrawler, 02-25-2013 11:38:39   That weldor could have done something similar to what I described down below on a reply to puddles. You need to ground and ground good as close to where you are welding as possible. There are some exceptions to grounding close.   [Reply]  [No Email]
Mutton Geoff 02-25-2013 07:16:14 71.169.174.203 Report to Moderator	Re: Ground for a welder in reply to Stan in Oly, WA, 02-25-2013 00:10:45   I was welding on a frame attachment of a non running SA200 I had the fast charger charging the SA200's battery 10a position I was welding with a small ac/dc lincoln stick in 7018DC electrode + when the battery I was charging exploded. THE BEST BATTERY explosion and I missed it.   [Reply]  [No Email]
kito169 02-25-2013 06:27:03 173.184.22.4 Report to Moderator	Re: Ground for a welder in reply to Stan in Oly, WA, 02-25-2013 00:10:45   In 1972 I was building a clean room for Texas Instruments to grow their silicon chips in. They grew them in a fancy oven which had an earth ground. While welding some ceiling channels in, with a Lincoln tombstone a/c welder, I was touching the ceiling channel which had the return/ground clamp attached with my hand and my butt touched the oven. The stinger was laying on the scafold. The electricity was passing throuh my body and I could not get loose. I could not say anything either. My Dad was on the floor rolling the scaffold around for me and saw something was wrong so he pushed the scaffold so I was not in contact with the oven anymore. I"ve never used an a/c welder since. d/c only for me   [Reply]  [No Email]
buickanddeere 02-25-2013 05:57:11 209.240.117.167 Report to Moderator	Re: Ground for a welder in reply to Stan in Oly, WA, 02-25-2013 00:10:45   Just trying to look out for your guys, your families, your friends, your co-workers and your property.   [Reply]  [No Email]
Stan in Oly, WA 02-25-2013 08:33:36 174.31.223.173 Report to Moderator	Re: Ground for a welder in reply to buickanddeere, 02-25-2013 05:57:11   I know you are, and I appreciate it. I mentioned you by name because it was your advice and your warnings that came to mind when I was considering running an experiment at home and trying to imagine what the consequences could be. Stan   [Reply]  [No Email]
David G 02-25-2013 05:52:17 205.215.206.18 Report to Moderator	Re: Ground for a welder in reply to Stan in Oly, WA, 02-25-2013 00:10:45   Yes, it should be called a return.   [Reply]  [No Email]
John T 02-25-2013 05:45:36 66.87.4.39 Report to Moderator	Re: Ground for a welder in reply to Stan in Oly, WA, 02-25-2013 00:10:45   Stan, good question and those are legitimate concerns, heres my engineers perspective. To lay persons, calling what most people call the GROUND CLAMP makes sense to them just as they call a tractors frame GROUND. You may confuse an untrained person if you go over their head trying to define terms that engineers and electricians and electrical techs commonly use. I call my welders ground clamp a ground clamp and did BOTH before and after my engineering career and call the other the stinger (electrode holder) BUT ALL ARE FREE TO CALL THEM ANYTHING THEY PLEASE LOL Ifffffffff youre talking about a cheap basic Lincoln Tombstone or other AC Buzz Box Welders, they are basically a simple isolation transformer and their output voltage is across their leads. The safety Equipment Ground is bonded to the welders metallic case to provide an independant dedicated low resistance path to carry FAULT CURRENT ONLY NOTTTTTTTTT Neutral current. As far as voltage potential from the ground clamp or stinger to mother earth or safety equipment grounding conductors or gas or water pipes or building steel or a concrete floor that depends on the welders design and the branch circuit wiring and length of wire (capacitance or mutual inductance) and I just cant say what it might be BUTTTTTTTTTTT I DONT LIKE THE IDEA OF TRYING TO USE OTHER THEN THE WELDING CABLE AS ANY RETURN PATH even though in theory (depends on welder) there should be low potential and low current. I cant speak for my friend the good Buick man, but the reason I tell people to NOT use the GroundING conductor for the Neutral (A GrounDED Conductor) and vice versa or to mix n match or swap or substitute one for the other IS TO EDUCATE THEM AND SAVE LIVES but I also say do as they well please, Im here to try and help maybe save a life, NOT argue or tell them what to do John T Long retired EE   [Reply]  [No Email]
Stan in Oly, WA 02-25-2013 08:59:24 174.31.223.173 Report to Moderator	Re: Ground for a welder in reply to John T, 02-25-2013 05:45:36   Thanks for the information, John. As far as terminology is concerned, I'm far from being a stickler about it. Insisting that aspiring metal artists say GMAW, GTAW, and SMAW rather than MIG, TIG, and stick is a non-starter, in any case. If the popular terminology has the potential to confuse understanding of the process, as in the ground vs. work lead issue, I try to mention it, but that's all. Insisting on using technical terminology (i.e. DCRP rather than just electrode positive) in setting where it's unfamiliar and unnecessary, can be a good way to cause confusion and reduce clear communication. Stan   [Reply]  [No Email]
John T 02-25-2013 13:41:47 71.52.99.130 Report to Moderator	Re: Ground for a welder in reply to Stan in Oly, WA, 02-25-2013 08:59:24   Youre welcome. As far as electrical terminology, Im convinced where the uneducated are concerned its because Dad and Grandpa called that white wire GROUND is why they do the same and when educated and experienced Electrical professionals say the word Neutral it just flys past them and they run to the panel and say seeeeeeeeeee the whites and grounds all go to the same place SO BY GOLLY THEY ARE THE SAME LOL John T   [Reply]  [No Email]
Stephen Newell 02-25-2013 04:48:37 66.53.83.226 Report to Moderator	Re: Ground for a welder in reply to Stan in Oly, WA, 02-25-2013 00:10:45   I think as far as operating a welder it's ok to call it a ground but if the discussion was wiring for the welder it would be a different story.   [Reply]  [No Email]
missouri massey man 02-25-2013 04:38:55 108.90.234.133 Report to Moderator	Re: Ground for a welder in reply to Stan in Oly, WA, 02-25-2013 00:10:45   Another story: My welding table is cluttered around the base with short pieces of good scrap. My good pedestal grinder is next to the table in contact with some of the scrap. Temporarily moved the ground clamp to the grinder pedestal to relocate the piece being welded and forgot to replace the ground clamp to this piece. Struck an arc, burned it for an inch before it quit, raising my helmet I see the grinder cord smoking all the way back to the outlet. You guessed it, the ground melted the cord from stem to stern, completing the workpiece ground through the electrical ground. But only for a short time. Bummer. I got lucky, so with this I would suggest not tempting fate.....   [Reply]  [No Email]
Bobkatz 02-25-2013 02:49:01 67.72.98.45 Report to Moderator	Re: Ground for a welder in reply to Stan in Oly, WA, 02-25-2013 00:10:45   While at work a while ago a guy was welding under a truck with an extention light that had a metal guard covering the bulb. Well the ground lead wasn't secured well enough & while trying to weld the current followed the ground in the light cord & fried the whole cord! Don't use the house ground! Bobkatz   [Reply]  [No Email]
Puddles 02-25-2013 03:34:36 24.113.77.208 Report to Moderator	Re: Ground for a welder in reply to Bobkatz, 02-25-2013 02:49:01   Back in my conveyor installing days, I burned up wiring going to conveyor motors. Jumping around, over, under conveyors welding on them you loose track of where your ground / work clamp is, you notice the welding machine is running colder but unless you have been guilty of burning wires up before you don't give it a second thought. But you learn a valuable lesson when the electrician tracks you down and chews your a$$ out! :oops:   [Reply]  [No Email]
JOB 02-25-2013 09:05:37 50.124.208.41 Report to Moderator	Re: Ground for a welder in reply to Puddles, 02-25-2013 03:34:36   Puddles we had some outside contractors come into our plant and ground to a nice clean pipe and do some welding on a conveyor or lift table or maybe part of a cross transfer conveyor at the end of two conveyors. The nice clean pipe was electrical conduit. After the contractors left and production started we had electrical problems half a dozen times per shift with the electrical equipment in the area. No one could track down the exact location of the problem. We lived with the problem until a long weekend or a summer or Christmas shutdown, can't remember which. The electricians went in and completely rewired all the affected equipment. Problem solved. Clamp the ground close to where you are welding. I know you know this now. Ever see a welder ground to a rail road track and weld to a box car? He might get more than a a$$ chewing.   [Reply]  [No Email]
MarkB_MI 02-25-2013 02:29:39 75.219.14.38 Report to Moderator	Re: Ground for a welder in reply to Stan in Oly, WA, 02-25-2013 00:10:45   Stan, that's a great question. I had to think about it a bit. I don't think there is much of a safety issue, but there is a definite possibility you could damage the shop's ground system. Most likely, the combined resistance of the circuit will be high enough to limit the current through the ground and just give you a weak arc. For example, if there's 10 ohms total resistance, you won't get more than 8 amps, which isn't going to damage anything. But let's say you have a particularly good ground, or you connect your work lead directly to a ground rod or a pipe that's bonded to ground. Now the current is limited only by what the welder can put out. The circuit you've created is unfused, which means the fuse is the whatever is the weakest link in the circuit. That might be a ground wire, a terminal connection or maybe your arc. If your arc isn't the weak link, somthing else is likely to blow. The thing to remember is that the ground circuit is designed to carry enough current to fault the largest breaker in the panel, but only for long enough to trip the breaker. A six gauge wire can easily handle a 100 amps for several seconds, but it can't handle it indefinitely. And there are other things in the circuit, such as screw terminals and receptacle contacts that could suffer arc damage. My recommendation is you don't do it. I think the risk of damaging the ground circuit is small but significant.   [Reply]  [No Email]