Wire fill/max. amount of conductors in troughs.

[Sparkyray122]

Installing a 1200A 480v 3ph service, feeder conduits tie into a ct cabinet first, then into the MDP, due to the layout of the mechanical room and the size of the cabinets and the location of the main 1200A breaker in the MDP, I want to feed the MDP from the ct cabinet with a trough. There will be 4 sets of 350mcm (16 wires). May I use a trough and if so how do I size it?

 

[dcspector]

This would be based on 366.22

 

[russ]

366.22 is a good place to start.
Then go to table 5 in the back of the book to find your conductor size. (.5242)
multiply .5242x16=8.3872 that will be the 20% allowed by 366.22
8.3872x5=41.936 sq inches. the square root of 41.936 is 6.4758011.
You need a trough bigger than 6x6.
Now you have to read 366.58

 

[ptonsparky]

... the square root of ...

The sound you hear is my head banging against the wall. I have been making that way to hard.