could someone help me find where it talks about derating and heat dissepation in a gutter. heres what i have; 8- 200amp 3phase 120/208 panels which are existing, its a TI. had to re-route all the homeruns to different panels, we cut all the pipes and put in a gutter that covers all 8 panels. this way we were able to re-route the homeruns without have to re-pipe. we re-pulled new wire and some have to cross over inside the gutter to a different panel. others we piped up and over that had to cross (horizontal) more than 2feet inside the gutter. we seperated all the conductors put them in pipes alone and put nuetrals and grounds going into the panel. My general foreman said something about not being able to this because of heat dissapation, he said grounds, nuetrals and conductors have to go into the same pipe. How is this going to change heat dissapation and where can i find it in the code book?