Conductor Rating in Cable Tray/Conduit (Multiple Parts)

[wallepog]

I have a tricky situation where multiple code issues may take place, so I'll try to give a good idea of what my dilemma is.

I have a conductor run traveling in ladder style, covered cable tray on a rooftop. It transitions to conduit at the rooftop edge and runs down the side of the building into a panel. All conductors are #1/0 75C (based on free-air table), and I'm am aware of the 60% de-rating factor. They are to be sized for 120A maximum load.

My questions are:
1. In addition to the 60% de-rating, does the allowable ampacity need to be de-rated in addition for temperature?
2. May 310.15(A)(2) come into play here? How would that exception affect the conductor sizing? I'm assuming it will vary based on if I can use the free air table or conductors in conduit table.

I have all the information I just need a bit of explaining. Let me know if you need more information. Thank you everyone!

 

[Smart $]

1) Yes, correction for ambient is required.

2) 310.15(A)(2) applies to all installations. Whether the Exception is applicable depends on the distances of each portion of the run having a different ampacity.