Welder Grounding

[T.M.Haja Sahib]

Maybe I overlooked it

:slaphead::slaphead:

:lol:

 

[Besoeker]

I just wanted to explore the possibility of death by ground leakage current due to welding return current on the basis of that fatal accident, as there is no way to establish the actual cause of that welder's death due to lack of sufficient data at hand.

It might have been completely unrelated to the actual welding.
Google Welder's Death.

"Warnings not to do any welding went unheeded and an explosion that killed a welder.."
"A 38-year-old male arc welder died as a result of an explosion at a construction company."
"Gaywood welder's death was smoking-related"
"A WELDER who worked in nuclear power plants wore asbestos-lined clothing for protection ? but it ended up killing him."
etc

And there's no guarantee that the newspaper reported it correctly anyway (see post#39).
So I think it's a dead duck.

 

[T.M.Haja Sahib]

It might have been completely unrelated to the actual welding.
Google Welder's Death.

"Warnings not to do any welding went unheeded and an explosion that killed a welder.."
"A 38-year-old male arc welder died as a result of an explosion at a construction company."
"Gaywood welder's death was smoking-related"
"A WELDER who worked in nuclear power plants wore asbestos-lined clothing for protection ? but it ended up killing him."
etc

And there's no guarantee that the newspaper reported it correctly anyway (see post#39).
So I think it's a dead duck.

Here is a link for your kind reference:

http://nasdonline.org/document/1858...n-electrocuted-while-welding-feed-bunker.html

See the last paragraph of 'Recommendations/discussion'. The report states that there is hazard due to ground leakage current between the welder and work that can not be detected by a GFCI.It is because that ground leakage current flows back to the transformer secondary via the work lead/exposed work lead splice lying on ground and so the GFCI can not detect it.This can also be a factor for the fatal accident of post #12.

 

[iwire]

But I am afraid you missed my point.

I just wanted to explore the possibility of death by ground leakage current due to welding return current on the basis of that fatal accident, as there is no way to establish the actual cause of that welder's death due to lack of sufficient data at hand.

We all have missed your point as you always talk in circles.:lol:

 

[hurk27]

Here is a link for your kind reference:

http://nasdonline.org/document/1858...n-electrocuted-while-welding-feed-bunker.html

See the last paragraph of 'Recommendations/discussion'. The report states that there is hazard due to ground leakage current between the welder and work that can not be detected by a GFCI.It is because that ground leakage current flows back to the transformer secondary via the work lead/exposed work lead splice lying on ground and so the GFCI can not detect it.This can also be a factor for the fatal accident of post #12.

I think, or should I say you should know, that a GFCI on the primary side of a transformer will not or can not protect from ground faults on the secondary side of a transformer, in understanding this you also should understand that the output of a welder is isolated by this very same transformer, no matter what someone is saying all the faults in the wiring ahead of this welder would not have caused a voltage to earth problem after this welder unless one of the leads would have come into contact with the line side conductors, now after reading the whole story, there are several things that make sense of why this death occurred, the farmer had spliced two sets of welding leads together, did not isolate the splices from earth as he laid them right in the dirt, it was said the earth was wet, he was sweating, and laid on bare wet ground, normally there would have been no reference to earth as the wagon was on rubber wheels, and the welder does not have any reference to earth on the secondary side of it, so if the leads would have been insulated from earth there would have been no pathway for current to flow that would have gone through his body, the second thing it in error they stated that the current flowed back to the welder through earth, no it flowed back to the uninsulated splice in the welding cable that was in contact with earth that gave the secondary reference to earth, these are simple current pathways that you should be able to follow to understand.

There is a reason that welder manufactures do not bond the output of a welder to the cabinet or an EGC, with the isolation effect of the transformer a welder only has one pathway that current can flow, and that is between the work lead and the welding lead, if the welder allows his cables to become in disrepair to the point they can make contact with earth or other grounded metal that will provide a another path, then they are not doing their job to keep themselves safe, equipment must be inspected before every job and after, I do not know a pilot who just jumps into a plane a just takes off, everyone of them has a check list that they are required to do before they ever move that plane, many jobs should have the same requirement.

simple point: Do Not Use Unsafe Equipment period !!!

 

[T.M.Haja Sahib]

We all have missed your point .

I want to bring to your kind information that the Briggs-Meyyer personality test revealed that there exist many personality types.Their way of thinking can be entirely different,So your contention'we all missed your point' can not be true.

 

[T.M.Haja Sahib]

..... the second thing it in error they stated that the current flowed back to the welder through earth, no it flowed back to the uninsulated splice in the welding cable that was in contact with earth that gave the secondary reference to earth,

No.The report is correct.The current flowed through the earth and returned to the welder through the uninsulated splice in the welding cable that was in contact with earth.

See the post#12 again.The grill work on which the welder was working was fixed to the ground.The work lead from the transformer secondary was fixed at a remote corner in the grill.This gave the ground reference as above.I already stated this in my previous posts.But you did not take it into account.Now do it.Also remember the condition of ground being damp.So there is bound to be ground leakage current as in the above case.Do you understand this or not?

 

[hurk27]

No.The report is correct.The current flowed through the earth and returned to the welder through the uninsulated splice in the welding cable that was in contact with earth.

See the post#12 again.The grill work on which the welder was working was fixed to the ground.The work lead from the transformer secondary was fixed at a remote corner in the grill.This gave the ground reference as above.I already stated this in my previous posts.But you did not take it into account.Now do it.Also remember the condition of ground being damp.So there is bound to be ground leakage current as in the above case.Do you understand this or not?

I was replying to your post #43 not post #12 in which you provided the link to which I read, I stand by my post as a response to your post #43, I agree that when a welder connects the lead to work that has a reference to earth then there is a reference to earth, but the path is not directly back to the welder, it is through earth to the work then through the work lead to the welder transformer, in a case as this it is the responsibility of the welder to not parallel himself between earth and the welding lead (stinger) as this can and will produce a shock.

 

[iwire]

I want to bring to your kind information that the Briggs-Meyyer personality test revealed that there exist many personality types.Their way of thinking can be entirely different,So your contention'we all missed your point' can not be true.

OK, you are correct, only the normal have missed your point, the abnormal understand you perfectly.:thumbsup:

 

[T.M.Haja Sahib]

OK, you are correct, only the normal have missed your point, the abnormal understand you perfectly.:thumbsup:

Your classification of whoever agrees with you as normal and others as abnormal is not indicated by Briggs-Meyers Personality test.

 

[T.M.Haja Sahib]

I was replying to your post #43 not post #12 in which you provided the link to which I read, I stand by my post as a response to your post #43, I agree that when a welder connects the lead to work that has a reference to earth then there is a reference to earth, but the path is not directly back to the welder, it is through earth to the work then through the work lead to the welder transformer, in a case as this it is the responsibility of the welder to not parallel himself between earth and the welding lead (stinger) as this can and will produce a shock.

Do you find any causative factors common between fatal accidents mentioned in post #43 and post #12 or not ?

 

[Besoeker]

See the last paragraph of 'Recommendations/discussion'. The report states that there is hazard due to ground leakage current between the welder and work that can not be detected by a GFCI.It is because that ground leakage current flows back to the transformer secondary via the work lead/exposed work lead splice lying on ground and so the GFCI can not detect it.This can also be a factor for the fatal accident of post #12.

Given the parlous state of the rest of the equipment, A GFCI wouldn't have worked. The report states that.
Couple of other points.

The welder was an old Hobart brand A.C. arc welder (See Figure 1). The welder's power cord covering and insulation was damaged which exposed the conductors (See Figure 3). The welder cables were not available to the MIFACE researchers. The condition of the cable insulation is unknown.........The second set of welding cables that were "spliced" to the first set was also not available for inspection.

So some speculation going on here.
What is clear from Fig 3 is that the power cord is damaged and the report mentions that.
The power chord doesn't look to be very big either and it's reportedly a 90A welder.
One might thus conclude that the output voltage was significantly lower than the input voltage. High enough to fatally electrocute the victim?
An equally plausible explanation might be that the exposed 240V conductors contacted the output side and raised the potential to that level and that's maybe what caused the problem.
Unrelated to the actual welding.

 

[T.M.Haja Sahib]

One might thus conclude that the output voltage was significantly lower than the input voltage. High enough to fatally electrocute the victim?

Even low voltage can kill,given damp conditions.

An equally plausible explanation might be that the exposed 240V conductors contacted the output side and raised the potential to that level and that's maybe what caused the problem.
Unrelated to the actual welding.

A contradiction because the transformer secondary lead was touching the damp ground through the open splice and should the transformer primary made contact with the secondary,the primary over current protective device would have operated and the fatal accident would have been avoided.

 

[don_resqcapt19]

...
A contradiction because the transformer secondary lead was touching the damp ground through the open splice and should the transformer primary made contact with the secondary,the primary over current protective device would have operated and the fatal accident would have been avoided.

Maybe, maybe not. Poor accidental connections often do not flow enough current to cause an OCPD to open.

 

[T.M.Haja Sahib]

Maybe, maybe not. Poor accidental connections often do not flow enough current to cause an OCPD to open.

To arrive at a simple explanation of that accident,assume enough current could flow and so, that possibility is eliminated.What then may be the cause of the accident?

 

[Besoeker]

Even low voltage can kill,given damp conditions.

And sufficient voltage. Was there sufficient voltage?

A contradiction because the transformer secondary lead was touching the damp ground through the open splice and should the transformer primary made contact with the secondary,the primary over current protective device would have operated and the fatal accident would have been avoided.

You would need a pretty good ground connection to get fault current to flow. A bare connection just lying on damp ground is hardly likely to act like a ground rod buried in it.

 

[Besoeker]

To arrive at a simple explanation of that accident,assume enough current could flow and so, that possibility is eliminated.

Why is it eliminated? The current required to cause a fatal electrocution is certainly going to much lower than the setting of any overcurrent device supplying the welder.

 

[T.M.Haja Sahib]

Why is it eliminated? The current required to cause a fatal electrocution is certainly going to much lower than the setting of any overcurrent device supplying the welder.

You can be right.I just want to know if I can also be right.That is all.

 

[Besoeker]

You can be right.I just want to know if I can also be right.That is all.

I think your point about the primary overcurrent device operating is most likely incorrect.
The rest we don't know about.

 

[kwired]

Output voltage of a welder can kill. Installing a grounding electrode system on the welder output will not change that. If anything it will give current more paths and increase the hazards. The work lead needs to be as close as practical to the work. Open circuit voltage is there no matter what. If you don't want to be exposed to that turn the welder off and then see how well it welds. If you don't want to be blinded by the arc you should either use a welding mask or again turn the welder off.