Hi everyone. I'm a 3rd year electrician but please don't be "shocked" by some of my questions. I'm finding that a lot of journeymen don't know the answers to theory type questions, and I'm the sort of thinker that needs to understand WHY something works before I can install it properly... I marvel at how guys can install large equipment without a clue as to how it works. Line in, load out I suppose. Anyway...
I'm reading some of the shock current path literature on the site here and have a few questions.
First, I work with a welder at an industrial site, installing/welding supports for cable tray. His welder has me perplexed. He can select the polarity of his welder, which he has set to positive, so the positive lead the the "hot lead."
The welder itself has a ground terminal which is not used. He has a positive lead (attached to his stick) and a negative lead (the working lead or clamp, which some welders erroneously call the "ground clamp") To weld, the working clamp has to be touching the work piece, and the positive electrode (stick) is sending DC current through the work piece and back to the welder on the negative work clamp, correct?
So I'm thinking of the different shock current paths.
One more question:
Does the theory behind DC shock current paths apply perfectly to AC systems? Or can AC systems shock in different scenarios than DC and vice versa?
I'm reading some of the shock current path literature on the site here and have a few questions.
First, I work with a welder at an industrial site, installing/welding supports for cable tray. His welder has me perplexed. He can select the polarity of his welder, which he has set to positive, so the positive lead the the "hot lead."
The welder itself has a ground terminal which is not used. He has a positive lead (attached to his stick) and a negative lead (the working lead or clamp, which some welders erroneously call the "ground clamp") To weld, the working clamp has to be touching the work piece, and the positive electrode (stick) is sending DC current through the work piece and back to the welder on the negative work clamp, correct?
So I'm thinking of the different shock current paths.
- A ground fault anywhere in his welding system will lead to a shock for a person touching the grounded section of the circuit **while he's welding**, because he isn't using the ground terminal on his welder.
- While he is not welding (incomplete circuit), a ground fault on the positive side of his system will lead to a shock (but this would be the case whether the negative side of his system was grounded or not, right?).
- A person can be shocked if they themselves are the only path for the current to flow through - say, by grabbing the positive and negative leads at the same time.
One more question:
Does the theory behind DC shock current paths apply perfectly to AC systems? Or can AC systems shock in different scenarios than DC and vice versa?
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