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Being shocked????

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  • Being shocked????

    I'm a Site Safety Rep for a welding company in Saginaw Mi, .. Just today we
    had a young man get shocked by a welding lead. He went to go pick up the welding lead at the connection of the two leads and wham he felt a good jolt. We are working out in the cold wet conditions of the great cold state of Michigan and so I told them to tape the connections and wear rubber gloves, I know that the wleding machines are plugged in to a GFCI plug but is that REALLY ENOUGH . Is there aything else I can do to prevent this from happening ..... Safety Rep Craig

  • #2
    being a safety rep you should know that by osha rules welding leads are not suppose to be taped up.


    • #3
      Was the machine set for AC or DC? You should know why it makes a difference.

      Do you know how a GFCI works? You should.

      What was completing the circuit? In other words where were the stinger and work lead connections, material, and such, relative to the person who was shocked?

      Are there exposed parts on the connectors? Is the insulation deteriorated at the connections or on the leads themselves? How did he contact the energized parts?

      Was there welding current flowing at the time, or was it in between welds and only open-circuit voltage was present? What machine was it and what is its OCV (open circuit voltage). You should know this and why it makes a difference.
      Last edited by MAC702; 12-11-2008, 09:50 PM.


      • #4
        The GFCI will NOT do any good if the machine is in proper working order since the output is isolated from the input. This isolation is an absolute requirement, as multiple machines may be connected to the same work, sometimes with different polarity. Due to the isolation, there will not be any differential between the current carrying leads powering the welder... there can be no detectable ground fault.

        The open circuit voltage on the output side of the welder can be sufficient to shock, though it is rare (not unheard of, only unusual) for the shock itself to cause injury. The major injury problem comes as a result of the startle response to the shock: falling off a ladder or scaffold, jumping and hitting your head, slipping and falling, etc.

        The principle safety precaution is to be sure that there are no exposed shock points. In the US, OSHA prohibits any repairs to leads in the 10 feet closest to the electrode holder/torch/gun and requires that repairs to the insulation where permitted be equivalent in quality to the original insulation. Taping is NOT prohibited, as long as it is not in the last ten feet and is equivalent to the original insulation.

        The requirement for junctions/connectors is a bit vague as to details, but, generally, specifies that connections must be insulated so as to be equivalent to the insulation on the cable under conditions of service. Commercial approved connectors (such as tweeco's) meet this requirement in dry conditions, and some types do in wet.

        If there is a concern, OSHA (and Worksafe BC, and other Canadian, US, and European safety agencies) require that the power source be turned off or isolated before handling leads. Rubber gloves are NOT a good idea unless the workers primary work task is handling electrical cables. Though they provide protection from shock, in my opinion the training requirement, testing and monitoring requirement (to insure the PPE is undamages), and risk due to misuse in a welding environment (they burn and melt) exceeds benefits. Other measures have the same benefit with lower risk.

        The best, cheapest, and fastest solution is proper training. How to recognize situations where there is a risk, how to reduce or eliminate the risk, and how to minimize the damage when the risk can not be totally eliminated. In your situation, recognize would include "am I standing in water?" and "Are the connections wet so there may be a path between the conductor and me?" Reduce or eliminate would include power the source down while doing other than incidental handling of leads and while reconfiguring the leads, using dielectric grease when making up the connections to provide some additional barrier against water getting to the conductor, using machines with low OCV circuits (many inverters have this: a sense voltage is maintained that is low enough that risk is eliminated, and when a touch to the work is sensed, the power source ups the voltage to strike and maintain the arc), using proper PPE (which may include insulating gloves, rated footwear, etc), and whatever else the situation dictates.

        Note that every day, thousands of welders work in wet, nasty conditions with minimal trouble. Most of these guys know how to recognize the risks and avoid them in their work, without cumbersome procedures. Training is the key. You might try a pipeliner (J.T., for example) for more information.
        I may not be good looking, but I make up for it with my dazzling lack of personality