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Monday, October 17, 2016
Question:
Re: CQD answer published Friday, October 7, 2016 -
In our experience connecting welders for our industrial customers. We have found that the conductors should be oversized to at least a #6 for this welder. The connections are the weak point. As we tighten the connection on a #10 wire the lug that is rated for several sized wires will not make as good of connection on the #10 as it will on the #6. With a #10 we will be back for repair service calls. Some of them will be warranty calls at a large cost to me and my customer for his downtime. I have also been told that a machine is only going to be used 20% of the time and as the process changes or the assembly line speed increases, it turns into 40% or more. We always oversize. I think the code has to consider these things and remove some of the derating allowances.
Tom Inman
A
Answer:
Hey Tom thanks for your comment. Make sure the termination is identified for the conductor size you are using. If it is and you are still having problems the manufacturer would probably want to know about it.
Sizing conductors to the NEC minimum can also result in weld quality that is not suitable due to voltage drop. The welder manufacturer might recommend larger conductors to help deal with this issue.