infinity said:What does the 75 v. 60 degree rating of the CB have to do with this?
smithacetech said:Are you trying to say you couldnt use the 75 deg chart for derating of the conductor ampacity if the lugs were rated at 60 deg?? You are not derating the lug ampacity just the conductors.
110.14(C) Temperature Limitations. . The temperature rating associated with the ampacity of a conductor shall be selected and coordinated so as not to exceed the lowest temperature rating of any connected termination, conductor, or device. . Conductors with temperature ratings higher than specified for terminations shall be permitted to be used for ampacity adjustment, correction, or both.
You guys are right. . I should have listed 3 separate items. . Let me edit my previous post.
He's mixing 3 things that shouldn't be mixed
1] . 240.4(D)
2] . lug/breaker temp column of T310.16, 240.4(B), 240.6(A)
3] . conductor temp column of T310.16, T310.15(B)(2)(a), 240.4(B), 240.6(A)
That's 3 separate things that give you 3 separate numbers and your OCPD can't be higher than the lowest number of any of the 3.
better ?
David
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