Mike Lamb Posted September 13, 2014 Report Share Posted September 13, 2014 Is there anything wrong with mixing SEC conductors metals? Click to Enlarge 30.77 KB Link to comment Share on other sites More sharing options...
mlparham Posted September 13, 2014 Report Share Posted September 13, 2014 Is there anything wrong with mixing SEC conductors metals? Click to Enlarge 30.77 KB Look at the corrosion on the lugs and you have your answer and your answer is yes, there is a problem with mixing materials. Link to comment Share on other sites More sharing options...
Jack Davenport Posted September 13, 2014 Report Share Posted September 13, 2014 The truth of the matter is there is NO problem with using copper for one leg and aluminum for another leg. The NEC is quiet on that. As long as each leg is sized properly why would there be a problem ? Each leg is completely independent of each other. Link to comment Share on other sites More sharing options...
kurt Posted September 14, 2014 Report Share Posted September 14, 2014 Both legs look like copper to me. Am I not seeing it correctly? Copper SEC into aluminum lugs. In that case, would paste make any difference? Link to comment Share on other sites More sharing options...
Jack Davenport Posted September 14, 2014 Report Share Posted September 14, 2014 Both legs look like copper to me. Am I not seeing it correctly? Copper SEC into aluminum lugs. In that case, would paste make any difference? My guess is they are both copper. The one is corroded/oxidized. I am willing to bet that they are not aluminum lugs. My reply was a general reply that one can use aluminum and / or aluminum as a feed/ feeder Link to comment Share on other sites More sharing options...
Mike Lamb Posted September 14, 2014 Author Report Share Posted September 14, 2014 The two red wires are AL. The black is CU. I'll assume that if the wires are sized properly and the breaker allows both AL/CU, mixing is not a problem. Link to comment Share on other sites More sharing options...
Jim Katen Posted September 14, 2014 Report Share Posted September 14, 2014 As long as the lugs are listed for use with either aluminum or copper, it's not a problem. Link to comment Share on other sites More sharing options...
mlparham Posted September 15, 2014 Report Share Posted September 15, 2014 As long as the lugs are listed for use with either aluminum or copper, it's not a problem. Then how do you explain the corrosion on the lugs? Link to comment Share on other sites More sharing options...
Jim Katen Posted September 15, 2014 Report Share Posted September 15, 2014 As long as the lugs are listed for use with either aluminum or copper, it's not a problem. Then how do you explain the corrosion on the lugs? Corrosion can be caused by all sorts of things other than incompatible metals. We all see it all the time. It could be that there were originally two aluminum wires, and one of them corroded and was replaced by copper. Link to comment Share on other sites More sharing options...
Jim Port Posted September 16, 2014 Report Share Posted September 16, 2014 The panel lugs should be listed for use with AL or CU. I have never seen any that were not dual rated. Link to comment Share on other sites More sharing options...
mtwitty Posted September 26, 2014 Report Share Posted September 26, 2014 The conductors appear to be the same size. This would be an issue if one is AL. (lower ampacity rating) Link to comment Share on other sites More sharing options...
Jim Katen Posted September 26, 2014 Report Share Posted September 26, 2014 The conductors appear to be the same size. This would be an issue if one is AL. (lower ampacity rating) Your eye might be better than mine, but there might also be some optical illusion because of the different colors. When I hold up a caliper to my screen, the two conductors seem to be nearly identical in diameter. Since compact stranded aluminum wire is typically smaller in diameter than copper wire of the same gauge, I suspect that the aluminum is at least one gauge larger than the copper. It's really hard to tell. Link to comment Share on other sites More sharing options...
kurt Posted September 27, 2014 Report Share Posted September 27, 2014 What about this? The whole mess was turning into white powder. Click to Enlarge 48.49 KB Link to comment Share on other sites More sharing options...
Jim Katen Posted September 27, 2014 Report Share Posted September 27, 2014 What about this? The whole mess was turning into white powder. It looks like the panel has gotten wet. Link to comment Share on other sites More sharing options...
Erby Posted September 27, 2014 Report Share Posted September 27, 2014 I'll see your corrosion and raise it to melting. Click to Enlarge 55.48 KB Link to comment Share on other sites More sharing options...
kurt Posted September 28, 2014 Report Share Posted September 28, 2014 Subsequent invasive investigation reveals past leak and epoxy repair......panel had indeed been wet. Link to comment Share on other sites More sharing options...
Jim Katen Posted September 28, 2014 Report Share Posted September 28, 2014 Subsequent invasive investigation reveals past leak and epoxy repair......panel had indeed been wet. What did they try to repair with epoxy? Link to comment Share on other sites More sharing options...
kurt Posted September 28, 2014 Report Share Posted September 28, 2014 Foundation crack at the service entry ell; finished basement covered it up. Sucker probably leaked for a decade, then someone finally patched it with epoxy injection. The equipment was shot. That white powder thing is wild; the disconnect had pretty much gone to borax; I don't know how it was conducting electricity. Link to comment Share on other sites More sharing options...
mjr6550 Posted September 29, 2014 Report Share Posted September 29, 2014 What about this? The whole mess was turning into white powder. Click to Enlarge 48.49 KB When I see that I look for water stains on the service entrance conductors entering the top of the panel. Water often enters the meter socket and flows into the panel. Click to Enlarge 35.81 KB Click to Enlarge 31.28 KB Link to comment Share on other sites More sharing options...
Jim Katen Posted September 29, 2014 Report Share Posted September 29, 2014 Aluminum wires don't like to get wet. I was working in my shop one day when I lost power on one leg of the 240-volt feeder. The pictures show what I found when I dug it up. Download Attachment: AL Corrosion Wet 1.JPG 366.03 KB Download Attachment: AL Corrosion Wet 2.JPG 177.74 KB Link to comment Share on other sites More sharing options...
Marc Posted September 29, 2014 Report Share Posted September 29, 2014 Aluminum wires don't like to get wet. I was working in my shop one day when I lost power on one leg of the 240-volt feeder. The pictures show what I found when I dug it up. Maybe because its anodic index is so high. Remember galvanic action between dissimilar metals? 2000 series wrought aluminum is -0.75 whereas copper is only -0.35. Marc Link to comment Share on other sites More sharing options...
Jim Katen Posted September 29, 2014 Report Share Posted September 29, 2014 Aluminum wires don't like to get wet. I was working in my shop one day when I lost power on one leg of the 240-volt feeder. The pictures show what I found when I dug it up. Maybe because its anodic index is so high. Remember galvanic action between dissimilar metals? 2000 series wrought aluminum is -0.75 whereas copper is only -0.35. Marc That could well be it, but I don't know what the cathode would be in that trench. There aren't any copper deposits here. Link to comment Share on other sites More sharing options...
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