I am looking for opinions on something.
I have worked at my company for 26 years and they have had a standard practice that the largest copper wire size we would ever specify would by #500 kcmil. As such, if a load was greater than 380 amps, we would use parallel conductors but never exceed the #500 kcmil wire size (even using 2 sets of #3/0 in lieu of one set of #600 kcmil).
The rationale behind this standard has been off-the-shelf availability and lug capacities for wire sizes larger than #500 kcmil. Maybe this rationale was valid before I joined the industry, but I am not so sure it is still legitimate.
I would like to change the maximum wire size we specify to #600 kcmil (possibly #750 kcmil) but before I do, I want to make sure I am not going to cause issues. So I have a few questions:
1. From what I've seen, if a lug will accommodate #500 kcmil wire, it will typically accommodate #600 kcmil wire. Is this true?
2. Is #600 kcmil or #750 kcmil wire more difficult to source than #500 kcmil wire?
3. Would anyone hesitate specifying or using #750 kcmil wire? I believe lugs could become an issue at #750 kcmil.
I appreciate anyone's input on this topic.
Jason Rohe, P.E.
I have worked at my company for 26 years and they have had a standard practice that the largest copper wire size we would ever specify would by #500 kcmil. As such, if a load was greater than 380 amps, we would use parallel conductors but never exceed the #500 kcmil wire size (even using 2 sets of #3/0 in lieu of one set of #600 kcmil).
The rationale behind this standard has been off-the-shelf availability and lug capacities for wire sizes larger than #500 kcmil. Maybe this rationale was valid before I joined the industry, but I am not so sure it is still legitimate.
I would like to change the maximum wire size we specify to #600 kcmil (possibly #750 kcmil) but before I do, I want to make sure I am not going to cause issues. So I have a few questions:
1. From what I've seen, if a lug will accommodate #500 kcmil wire, it will typically accommodate #600 kcmil wire. Is this true?
2. Is #600 kcmil or #750 kcmil wire more difficult to source than #500 kcmil wire?
3. Would anyone hesitate specifying or using #750 kcmil wire? I believe lugs could become an issue at #750 kcmil.
I appreciate anyone's input on this topic.
Jason Rohe, P.E.