That different people view threads from different perspectives. Ten people will probably notice much more than ten different things about a thread. Some things they notice will be the same. The longer the thread, the more to note. Just different perspectives, not much more than that.
I have found some interesting things and some entertaining things so I keep reading even though it is a long thread. Don't mind me. Carry on.
Thanks for the clarification.
I know, Im commenting on everything in this thread :lol::ashamed1:
However lots of perspectives thus far, all valid concerns/observations/perspectives. Half the stuff I would not even have thought of.
Im really curious what Mr. Zappa obtains for conductor temps in common situations such as a fiberglass sandwich or fiberglass insulated wood stud sandwich.
After crunching numbers and sifting through data best I can (though I am very humble), I have come up with a theory (which I will use as base reference) that the 90*C column is based on an operating temperature rise of 44 to 55*F at full load, 3 conductors at 86*F. If true this alone would justify restricting NM to the 60*C column as adding thermal insulation would significantly increase temperature rise when measured after thermal normalization (equilibrium) resulting in actual temperatures well over 140*F.
However, there is one fact which challenges my theory. If we restrict NM for these reasons, then why do we de-rate starting from the 90*C column? And, alike, also challenging 240.4 (D); surely a conduit with 9 CCC #14 conductors each running at 15 amps will run hotter then only 3 conductors carrying 15 amps under identical conditions.
Mr. Zappa's testing will give actual numbers to prove or disprove our theories as well as providing a solid reference to work with.
