# grounding the workpiece you're welding



## jarnold (Sep 6, 2010)

I'm alittle confused. I just brought a mig welder and the safety section in the op manual says that the workpiece needs to be grounded independent of the ground to the welder. If I have a workpiece to be welded that is touching the concrete floor in my shop, do I need to ground that piece in addition to the welder ground clamp?


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## vsheetz (Sep 28, 2008)

You only need to clamp the ground clamp onto the work you are welding. You are looking to complete the circuit from the welding electrode wire, through the work, back to the welder.


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## bobelectric (Mar 3, 2007)

I'm glad someone takes the time to really study the owners manual.


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## Speedy Petey (Feb 1, 2004)

bobelectric said:


> I'm glad someone takes the time to really study the owners manual.


I completely agree, but in this case I am wondering what they are talking about. 
Maybe it's a CYA move in case of a fault it will trip the breaker?


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## AllanJ (Nov 24, 2007)

Speedy Petey said:


> IMaybe in case of a fault it will trip the breaker?


Yes.

Or at least prevent a surprise shock. Even for a fault producing a small voltage differential including a voltage differential with the concrete floor, that could cause the worker to lose control and perhaps burn himself.


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## Speedy Petey (Feb 1, 2004)

I have done a LOT of work in working welding shops and I have never seen anyone ground a piece other than with the welder ground. :huh:


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## fabrk8r (Feb 12, 2010)

I think what the manual writer meant by this statement:


jarnold said:


> workpiece needs to be grounded independent of the ground to the welder.


...is that the workpiece needs to be grounded using the dedicated ground clamp attached to the welder, and not by grounding through the welder's power supply.

It's definitely a CYA on the part of the company that manufactures the welder.


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## H. A. S. (Aug 18, 2010)

Speedy Petey said:


> I have done a LOT of work in working welding shops and I have never seen anyone ground a piece other than with the welder ground. :huh:



Same here.:thumbsup:


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## nap (Dec 4, 2007)

fabrk8r said:


> I think what the manual writer meant by this statement:
> 
> ...is that the workpiece needs to be grounded using the dedicated ground clamp attached to the welder, and not by grounding through the welder's power supply.
> 
> It's definitely a CYA on the part of the company that manufactures the welder.


I believe fabrk8r has explained it properly. It is also a poor explanation by the manufacturer.


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## Stubbie (Jan 7, 2007)

Just to expand the conversation I think there might be something to learn about what is really going on in a welding circuit. Underlines are mine. BTW I am by no means an expert on welding but this is how I understand things from what an old pipefitter has explained to me.

The terms 'ground lead' or 'ground clamp' are commonly used to describe the connection from the welding machine to the work ...the other connection being the electode lead or gun lead. A ground is not made with either the welding lead called a ground clamp or ground lead these are incorrectly used terms.... the correct term is *work lead*. What your doing is completing a current carrying welding circuit....
The welding machines frame is grounded via the equipment ground of the power supply... it has no connection to the work piece or* metal* work table through either the 'work lead' or 'electrode lead'..



ANSI Z49.1, "Safety in Welding, Cutting and Allied Processes," the workpiece or the metal table that the workpiece rests upon must be grounded. We must connect the workpiece or work table to a suitable earth ground, such as a metal building frame. The ground connection should be independent or separate from the welding circuit connections.

MY understanding is this is to 'bond' the work area so that the same potential exists to any two points you come in contact with while welding.. Few welders worry about this because they are wearing insulating gloves and clothing.

So I agree that you rarely see this done but appears to me it is recommended. 

I'm not a welder so not sure if this would be disputed by others more schooled in the field. 

Thought I would throw my understanding into the fire to see if it leads us to a correct understanding of grounding the work piece or table.


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## nap (Dec 4, 2007)

Stubbie said:


> MY understanding is this is to 'bond' the work area so that the same potential exists to any two points you come in contact with while welding.. Few welders worry about this because they are wearing insulating gloves and clothing.
> 
> So I agree that you rarely see this done but appears to me it is recommended.
> .


I've got to admit I have never been concerned with my workpiece being grounded.


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## fabrk8r (Feb 12, 2010)

I have been a weldor for over 20 years and I have found over time there are several methods to ground your workpiece to create the necessary circuit to allow a successful weld.

The best way is to attach the ground clamp directly to the workpiece. To expand on this, some welding processes, TIG for example, can best be performed if the ground clamp is in very close proximity to the electrode. This prevents a straying arc common with the TIG process.

It isn't always necessary to have the ground clamped directly to your workpiece. If you are using a welding table that is a good conductor the ground can be clamped directly to the table, allowing easier repositioning of the workpiece, which is useful if there is a need to change the direction of the weld due to numerous odd angles. One drawback to using this method of grounding, as opposed to directly clamping the ground to the workpiece, is that the surface of the workpiece can be damaged through arcing because of poor contact to table. This will not be much of a concern if the workpiece is strictly functional and not decorative, but can ruin a project if using stainless steel or aluminum material. 

One concern with a poor ground is that the weldor's own body can become the conductive path that completes the circuit. This is especially dangerous in wet situations or if the weldor is perspiring. I've received substantial shocks when welding due to having a poor ground, the ground coming detached, or from just not paying attention. I've had a good ground connection and still gotten a shock because I leaned up against my workpiece between where the ground was clamped and where I applied the electrode because I had my finger resting on the welding rod. I saw a co-worker fall from a ladder while welding in the rain because he had one hand on the steel stack he was welding and he touched the electrode with the other hand.

There are situations, such as when welding high up in a large factory, when it isn't practical to clamp the ground directly to the workpiece. In this situation a suitable ground can usually be had by clamping the ground lead to a steel beam or the building's metal siding. This allows the welder to be positioned far from the work using only a short ground lead with the long electrode lead being the only thing the weldor needs to be concerned with.


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## jarnold (Sep 6, 2010)

Thanks guys for your input. Fabrk8r, when you refer to ground clamp in your last post, are you talking about the ground clamp from the welder?


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## nap (Dec 4, 2007)

fabrk8r said:


> I have been a weldor for over 20 years and I have found over time there are several methods to ground your workpiece to create the necessary circuit to allow a successful weld.
> h.


I believe you are misunderstanding the term "grounding" here. Your explanation speaks of the work lead (refer to post #10 by stubbie). Grounding is a totally different issue. The grounding has nothing to do with the function of the welding circuit. It is completely a safety issue.


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## fabrk8r (Feb 12, 2010)

jarnold, yes, the ground clamp from the welder.

nap, the first post I added to this thread was to help clear up the confusion the OP has concerning the term "ground" in reference to the welding circuit.

The welding circuit ground is totally independent from the power source. For the welding process to occur there has to be a complete circuit and this circuit has nothing to do with the "earth" ground in the power circuit.


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## jarnold (Sep 6, 2010)

Nap. I'm not misunderstanding the term. All I'm asking is: does the workpiece or metal table its on need to be grounded separate from the welder's work clamp. And does a metal piece resting on concrete constitute a ground. thanks


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## nap (Dec 4, 2007)

fabrk8r said:


> The welding circuit ground is totally independent from the power source. For the welding process to occur there has to be a complete circuit and this circuit has nothing to do with the "earth" ground in the power circuit.


yes, I am quite aware of that. The reason I said anything is you were speaking of putting the "ground clamp" close to your weld when working with GTAW welding. 



> The best way is to attach the ground clamp directly to the workpiece. To expand on this, some welding processes, TIG for example, can best be performed if the ground clamp is in very close proximity to the electrode. This prevents a straying arc common with the TIG process.


the work clamp placement would be of concern for this but not the ground clamp. If things work well, the ground clamp should have no effects on the weld at all. It is only for the purpose of providing a 0 difference of potential between the work piece or table and any other conductor the operator might come into contact with. That 0 difference of potential will prevent current flow through the operator if he should contact both points at the same time.


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## fabrk8r (Feb 12, 2010)

jarnold, the concrete, or earth, will not constitute a "ground" as far the the welding circuit. You'll need to connect the actual ground clamp the the workpiece, or table.


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## nap (Dec 4, 2007)

jarnold said:


> Nap. I'm not misunderstanding the term. All I'm asking is: does the workpiece or metal table its on need to be grounded separate from the welder's work clamp. And does a metal piece resting on concrete constitute a ground. thanks


I didn't say you were, at least I don't recall where I did. Maybe I missed something I said to you but I do not believe I did.:wink:



> does the workpiece or metal table its on need to be grounded separate from the welder's work clamp


as stubbie provided, it should be. 



> And does a metal piece resting on concrete constitute a ground.


not a dependable connection. When concrete is used as part of a grounding electrode in the NEC, it is only with metal being within the concrete and it is the metal that must be connected to.


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## nap (Dec 4, 2007)

fabrk8r said:


> jarnold, the concrete, or earth, will not constitute a "ground" as far the the welding circuit. You'll need to connect the actual ground clamp the the workpiece, or table.



not trying to start an argument but where have you ever seen a welder with a "ground clamp"?

the ground connection being referred to in this situation has nothing to do with the machine.


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## jarnold (Sep 6, 2010)

fabrk8r, Yes, I know the work clamp has to be clamped to the workpiece or table. But if you need to separately ground the workpiece for safety, does a workpiece connected to concrete constitute a ground.


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## fabrk8r (Feb 12, 2010)

nap, I know it seems like it shouldn't matter where the ground clamp is positioned, and for most welding processes it won't, but there is something about the GTAW, or TIG, process that will make the arc deflect under certain circumstances.

I fabricate a lot of stainless steel sinks and countertops and when welding where three surfaces meet it is almost impossible to control the direction of the arc unless the ground is positioned very close to the weld. An added advantage to this is that since there is little distance between the ground and the electrode it makes it less likely that my body will short the circuit and get a shock, which commonly happens in out-of-position welding.


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## fabrk8r (Feb 12, 2010)

nap, every welder I've ever seen has a ground clamp.

I'm sorry, I should have used more appropriate semantics...when I say ground clamp, I mean work clamp...I'm a fabricator, not an English teacher. 


I apologize for the confusion. I know that all my fellow workers would look at me funny if I said "work clamp".


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## fabrk8r (Feb 12, 2010)

jarnold, there is no need for a separate ground.


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## nap (Dec 4, 2007)

fabrk8r said:


> nap, I know it seems like it shouldn't matter where the ground clamp is positioned, and for most welding processes it won't, but there is something about the GTAW, or TIG, process that will make the arc deflect under certain circumstances.
> 
> I fabricate a lot of stainless steel sinks and countertops and when welding where three surfaces it is almost impossible to control the direction of the arc unless the ground is positioned very close to the weld. An added advantage to this is that since there is little distance between the ground and the electrode it makes it less likely that my body will short the circuit and get a shock, which commonly happens in out-of-position welding.


but i ask again; have you actually seen a welder with a ground clamp? 

it sounds like you are speaking of the work lead and I am not disagreeing with your points on that. I understand the process well enough to know what you are speaking of with the arc.



> But if you need to separately ground the workpiece for safety, does a workpiece connected to concrete constitute a ground.


 no. while there will likely be some connection to ground through the concrete, simply setting on the concrete itself is not an acceptable grounding point or connection. When you are directed to connect the table to "ground", it is implied the "ground" is the building grounding electrode system or equipment grounding system. Concrete in itself is not part of that system. The intent is to provide a 0 difference of potential between any two points you might contact. Since the building power is providing the power to the welder, the only ground that would provide a safety factor would the the premises power source grounding system. The concrete of the floor is not part of that system by itself.


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## nap (Dec 4, 2007)

fabrk8r said:


> jarnold, there is no need for a separate ground.


you are incorrect. Stubbie presented contrasting information from a dependable source.

the fact you and friends are getting shocked proves why you do need an actual ground connection. That would prevent, or at least minimize, the shocks you are experiencing.


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## fabrk8r (Feb 12, 2010)

nap said:


> but i ask again; have you actually seen a welder with a ground clamp?


nap, yes, as I said every welder I've ever used, and I've used hundreds, had a ground clamp, or "work clamp" if you prefer.

Here is an example of an electrode holder, or stinger, on the left used for SMAW (shielded metal arc welding, or stick welding) and a common ground clamp on the right. Without either you'll have a hard time making a weld.


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## nap (Dec 4, 2007)

> =fabrk8r;496788]nap, yes, as I said every welder I've ever used, and I've used hundreds, had a ground clamp, or "work clamp" if you prefer.


that is the point and you even spoke to it as well. Technically it is not a ground clamp but a work clamp. This thread is dealing with actual grounding whether it be via a clamp or a permanent connection, which the work clamp does not provide. There should be (although I will admit it is rarely utilized from what I have seen) a ground connection to the work table and the work piece.

I cannot say I have ever seen a welder with an true ground clamp. (including the one you provided a picture of) .
Ground clamp is a commonly used misnomer used to indicate the work clamp.


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## Stubbie (Jan 7, 2007)

sorry I had to run a few errands but when I returned I read thru my millermatic 225 manual and found this statement



> If earth grounding of the workpiece is required, ground it directly
> with a separate cable


Now the question is ....When is earth grounding of the work piece required ?


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## nap (Dec 4, 2007)

Stubbie said:


> sorry I had to run a few errands but when I returned I read thru my millermatic 225 manual and found this statement
> 
> Now the question is ....When is earth grounding of the work piece required ?


well, I guess when ANSI standards are requrired to be followed:



> ANSI Z49.1, "Safety in Welding, Cutting and Allied Processes," the workpiece or the metal table that the workpiece rests upon must be grounded. We must connect the workpiece or work table to a suitable earth ground, such as a metal building frame. The ground connection should be independent or separate from the welding circuit connections.


btw, NEC 630.15 clearly states that the secondary of the welder shall not be considered as premises wiring fro the purpose of applying article 250 (Grounding and Bonding).

that would support your statement that the grounding must be separate of the work conductors.


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## Stubbie (Jan 7, 2007)

Here is the entire ansi welding saftey standard from the free download over on the american welding society website. I don't have time today to sort through it but maybe it will lead us to our answer about grounding the work piece. 
But as you said it does require it in the small section of that standard I qouted earlier..... 

http://files.aws.org/technical/facts/Z49.1-2005-all.pdf


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## Stubbie (Jan 7, 2007)

> btw, NEC 630.15 clearly states that the secondary of the welder shall not be considered as premises wiring fro the purpose of applying article 250 (Grounding and Bonding).
> 
> that would support your statement that the grounding must be separate of the work conductors.


HMMMM nice find and I agree it supports my understanding for grounding the workpiece.


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## a7ecorsair (Jun 1, 2010)

My art work isn't quite as nice as Stubbie's but I hope it gets the point across.
A simple welder is nothing but transformer and this transformer provides isolation between the primary and secondary winding. In other words, there is no current path between the two sides. The primary side has 240V and a ground - an equipment ground. The secondary side, the welding side, has no connection to anything other than what the work clamp, sometimes called a ground, and the electrode - the transformer isolates the primary from the secondary side. If you leave the work clamp disconnected and touch the electrode to earth ground, there will be no current flow. You cannot strike an arc.


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## Stubbie (Jan 7, 2007)

Some really nice windings you drew there a7ecorsair ...:thumbsup: 

Ok here is my issue and maybe some one can clear it up for me. Current wants to return to its source so it does that over the electrode lead thru the workpiece to the work lead then back to the welder (source). If I ground the workpiece or metal work table to lets say building steel which could be part of the grounding system of the premise wiring. If the work lead clamp would for some reason come off the work piece would I not have another path to the source and thereby energizing building steel and egc's so on and so forth?? Would not the welder possibly continue the arc even if the welding clamp was disconnected?


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## a7ecorsair (Jun 1, 2010)

With the work clamp disconnected and not touching anything there is no current path on the secondary side at all. The winding insulation electrically separates the primary side and the secondary side so there is no way the current can go any where.
Since it is a transformer the only difference between the two secondary poles, the work clamp and electrode holder, is the polarity of instantaneous voltage. With the welder on and neither the clamp nor the electrode touching anything it will have an open circuit voltage of maybe 30 volts but no current flow. I can then connect the work clamp to anything *or* the electrode to anything but not both or I will start welding.


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## Stubbie (Jan 7, 2007)

I'm not sure if that would be correct. In a warehouse building steel is almost always part of the grounding electrode system of the premise wiring and grounded to the utility neutral. If the work lead clamp came off the work piece it would open the welding circuit to the welder then current would flow to the welder power source.. the welder transformer.. over the separate ground.... Just like a ground fault. If you would ground the work lead , metal work table or work itself to building steel or some other low impedance path you could open the breaker protecting the welding circuit immediately on loss of the work clamp connection.

The other benefit I see is maintaining voltage potential with other grounded objects like the metal work table. In the event you had some kind of failure in the welder this would limit the voltage between the work piece and ground.

Now if I don't have the work piece grounded and the work clamp comes off the work piece the breaker will not open and an open circuit will exist with a 'hot electrode' at open circuit voltage which is a bit higher than when you are actually welding. If I don't turn the power supply off at the welder and grab the work clamp and somehow manage to touch the electrode also or a bare area on the welding cable to the electrode stinger then it would be possible everything being right to complete the welding circuit and get zapped.

I only think this way because you have to determine why the ansi standard in safety requires this separate ground lead. So this is what I have to think is going on ... whether it is right or wrong is still possibly a mystery at this point.


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## Stubbie (Jan 7, 2007)

OK just before calling it a night I found this in the miller weld technical library so lets see if we can sort this out later ... time to call it a day

*1. The Power Source and Primary Power Line*
*Grounding the Equipment*
Welders must be concerned at all times about the possibility of electrical shock. Wet working conditions must be avoided, because water is an excellent conductor and electricity will always follow the path of least resistance. Even a person's perspiration can lower the body's resistance to electrical shock. Standing on a dry rubber mat or, when welding outdoors, standing on a dry board is always advisable. Poor connections and bare spots on cables further increase the possibility of electrical shock, and therefore, daily inspection of these items is also recommended.
Aside from these more obvious shock hazards, equipment operators should routinely inspect for proper ground connections. A proper ground connection is always necessary because it provides a safety connection from a welding machine frame to the earth. Connections typically used for grounding an engine-driven welding machine include a cable connected from a ground stud on the welding machine to a metal stake placed in the ground.
The workpiece being welded and the frame or chassis of all electrically powered machines must be connected to a good electrical ground. This can be accomplished by connecting it to a properly grounded building frame or other appropriate ground. Chains, wire ropes, cranes, hoists and elevators must never be used as grounding connectors.
The work lead is not the grounding lead. The work lead connects the work terminal on the power source to the workpiece. A separate lead is required to ground the workpiece or power source.
When arc welding equipment is properly grounded according to the National Electrical Code, and to ANSI Z49.1 "Safety in Welding and Cutting" standards, a voltage may safely exist between the electrode and any conducting object. Examples of conducting objects include buildings, power tools, work benches, welding power source cases and workpieces. Never touch the electrode and any metal object unless the welding power source is off.


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## a7ecorsair (Jun 1, 2010)

Stubbie said:


> If the work lead clamp came off the work piece it would open the welding circuit to the welder then current would flow to the welder power source.. the welder transformer.. over the separate ground....


Look back at my sketch and note that the work clamp is not connected to the welder frame nor the EGC. Therefore, there is no path for current flow on the secondary side unless both the work clamp and electrode complete the circuit. And, unless the insulation in the transform windings has failed, there is no path to the primary side.



> Just like a ground fault. If you would ground the work lead , metal work table or work itself to building steel or some other low impedance path you could open the breaker protecting the welding circuit immediately on loss of the work clamp connection.


Nope, loose the work clamp and it just stops welding. 
FYI - A welder is really an impedance matching transformer. The primary being high impedance and the secondary low impedance. This will actually support a short circuit on the secondary side without tripping the breaker.
I can weld a car frame with the car sitting on its rubber tires and I'm sure you're heard about welding underwater... Have you heard of someone using a welder to thaw a frozen pipe?



> The other benefit I see is maintaining voltage potential with other grounded objects like the metal work table. In the event you had some kind of failure in the welder this would limit the voltage between the work piece and ground.


Yes, the work piece can be "grounded" but think about this:
Would welding current flow to the EGC? No, the current has to return to the same place it originated - the secondary winding.


> Now if I don't have the work piece grounded and the work clamp comes off the work piece the breaker will not open and an open circuit will exist with a 'hot electrode' at open circuit voltage which is a bit higher than when you are actually welding.


Yes, you will have open circuit voltage between the electrode and the work clamp but there is no open circuit voltage between the EGC and and the electrode.


> If I don't turn the power supply off at the welder and grab the work clamp and somehow manage to touch the electrode also or a bare area on the welding cable to the electrode stinger then it would be possible everything being right to complete the welding circuit and get zapped.


Yup, you could based on the open circuit voltage of the secondary.

Update:
I just did some testing with my Lincoln 225 AC welder.
Open circuit on the secondary is 83 volts AC. Electrode to EGC with work clamp isolated is 2 VAC - maybe some stray AC
With the welder on and the work clamp isolated, the electrode can be touched to any grounded metal with out any current flow or sparks.


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## Stubbie (Jan 7, 2007)

Ok I'm getting closer to understanding... like everything your new to sometimes it takes a while to digest thru all the different opinions. But I tend to agree with you. It appears the major benefit is maintaining close to equal voltage potentials around the work area.

Let me show you the comment I found from an experienced electrician that that just had me thinking otherwise.



> We need some clarification and interpreation on this conflict:
> NEC NFPA 70 Article 630-15: "Objectionble current in welding output circuit"
> 
> ANSI Z49.1
> ...


Answer



> The problem whit all this, is many don't understand that current only wants to return to source, each time you have installed a transformer in a system, it creates a new source, even a welder is a source, and the current it provides will try to return to it.
> 
> I have worked in many weld shops as an electrician, and I have seen the results of bonding the work piece to the building independent of the weld leads. the HF AC used in some types of welders only returns to the source that created it, the welder supply.
> The problem with bonding the work piece to the building or the building grounding system, is the two paths that the welding current can take, if the welder lead connection to the work piece is lost for any reason (and it happens all the time), then all the current will try to return to the welder power supply via the building through the grounding system or the EGC's of the electrical system (which can have disastrous consequences).
> ...


 __________________


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## a7ecorsair (Jun 1, 2010)

There are some good points in this but there are a few that are questionable. I'm sure the welding manufactures have to point out any possible circumstance so the lawyers don't get a hold of something in a law suit.
This is by far the most accurate comment:


> Grounding and Arc Welding Safety:
> Grounding the workpiece has similar benefit to grounding the welding machine enclosure. When the workpiece is grounded, it is at the same potential as other grounded objects in the area. In the event of insulation failure in the arc welding machine or other equipment, the voltage between the workpiece and ground will be limited.


This too is accurate. The welder secondary is the new source and is isolated from the primary.


> The problem whit all this, is many don't understand that current only wants to return to source, each time you have installed a transformer in a system, it creates a new source, even a welder is a source, and the current it provides will try to return to it.


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## Stubbie (Jan 7, 2007)

Yeah I agree with that . Anyway I learned something that I didn't know and that is always a plus.


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## AllanJ (Nov 24, 2007)

a7ecorsair said:


> FYI - A welder is really an impedance matching transformer. The primary being high impedance and the secondary low impedance. This will actually support a short circuit on the secondary side without tripping the breaker..


The load on an arc welding circuit is the arc itself and is of a very low resistance or impedance. If you accidentally touch the electrode to the work, the arc extinguishes and you get a dead short. Either the impedance of the secondary itself is high enough that even a dead short won't draw enough secondary circuit current to overheat it (impedance protected), or a low enough load resistance will cause enough current to flow in the primary to trip the breaker.

If the work clamp comes off the work piece then the current flow stops unless there is a fault in the secondary winding or other part of the secondary circuit. Now if the work clamp falls and lands on metal structure such as a catwalk and also the work piece is grounded, then the secondary circuit could be completed again. The welding current from the work clamp could possibly travel far and wide to get back to the work piece via a workpiece grounding cable and clamp and restrike the arc and return up into the hand held electrode.


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## GOLFJR (Jan 3, 2016)

*While I'm sure all who believe it is not necessary to ground your table...*

*From the Lincoln Electric website: *​*Grounding and Arc Welding Safety *

*Workpiece Ground
*The welding circuit consists of all conductive material through which the welding current is intended to flow. Welding current flows through the welding machine terminals, welding cables, workpiece connection, gun, torch, electrode holder and workpiece. The welding circuit is not connected to ground within the welding machine, but is isolated from ground. How do we ground the welding circuit?
​ According to ANSI Z49.1, "Safety in Welding, Cutting and Allied Processes," the workpiece or the metal table that the workpiece rests upon must be grounded. We must connect the workpiece or work table to a suitable ground, such as a metal building frame. The ground connection should be independent or separate from the welding circuit connection.


I realize that we seldom do this but it seems it is a good and maybe even necessary idea.
​


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## NotaDIY/Pro (Nov 10, 2013)

Wow, it's only January 3rd and this certainly must be a record for resurrecting a 5 year old thread from a "Newbie". Good job GolfJR. Your google skills are wonderful and your copy and paste buttons work excellent! Sheese!


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## calmdownladies (11 mo ago)

NotaDIY/Pro said:


> Wow, it's only January 3rd and this certainly must be a record for resurrecting a 5 year old thread from a "Newbie". Good job GolfJR. Your google skills are wonderful and your copy and paste buttons work excellent! Sheese!


only replying as you've been nasty to the chap above who was just trying to help, this will really trigger you then  ....you ladies really like to argue eh, here's the whole thread in simple terms.

1. the work piece needs to be clamped to the welding circuit - this completes the welding circuit and the current then flows and melts the metal between electrode and clamp. lazy/old people traditionally call it a ground clamp, like they say electrons flow from positive... it's not a ground, it's circuit return (+ or - but no need to confuse)
2. the work TABLE (aka the return of the welding circuit) should be grounded as you are making a large item that you can touch part of the welding circuit. if the transformer fails and no longer isolates the welding circuit you'll get a 240v shock, if it's connected to earth aka grounded you won't - this is good practice but not essential (more likely the tranny will go bang or even more likely the RCD will trip before you touch it) - welding in the rain, i'd ground to be safe.
3. don't ever touch both sides of the welding circuit and you'll be fine (if you do then you'll weld you, not the metal). welding circuit and supply circuit should be isolated by teh transformer so all a ground will do is make one part of the weldking circuit equal to supply ground. almost no one does this on the job as you risk tripping modern main breakers as they may see potential on the ground....explain that to the factory boss as all the machines need reset.....

Welding circuit - postive, negative
(isolation transformer)
Electrical supply - positive, negative, ground

if you ground the table the supply current goes to ground rather than you if there's a fault.

phew, you lot are worse than girls.


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## Jim Port (Sep 21, 2007)

I hope this was resolved 6 years ago.


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