2008 EXAM PREP BOOK ERROR?

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bbilotta

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Can anyone tell me if the temperature correction examples on pages 176 and 177 of the 2008 exam prep book are known errors? Page 176 references a correction factor of .71 for 60*C, the correct factor should be .77 according to NEC 2008 as well as 2011. Page 177 references a correction factor of .91 for a 100*F example while the 08 and 11 NEC show the correction factor to be 1.00 for 96-104*F. Prepping for a test next week and just want to make sure i'm not missing something.
 
The correction factors are based on temperature so it is hard to follow when you say 60C without a temp. That being said I don't see a .77 as a correction factor under 60C--- .71 is correct.
 
Dennis Alwon said:
The correction factors are based on temperature so it is hard to follow when you say 60C without a temp. That being said I don't see a .77 as a correction factor under 60C--- .71 is correct.
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I think he meant 60C as the ambient temp, not the insulation rating. For a 90C conductor, 0.71 would be right for a 60C ambient, and 0.91 would be right for a 104F ambient.

He appears to be reading Table 310.20 - "Supported on a messenger" (NEC 2008) to get 0.77 for 60C ambient and 1.00 for 100F ambient, rather than Table 310.16.
 
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