conduit fill usins 3/c calble 1

[fjconair]

NEC states dimensions & percent area of conduit/tubing 1-wire. 2-wire etc. There's personal saying a 3/c conductor is to be used as over 2 wires @ 40% code states 3/c used as 1-wire 53%, problem is I can't put my finger on this Article,please point me in the right direction on this subject. Thank you

 

[davidbeach]

If you are pulling in one thing, regardless of what's inside the thing, then use the one conductor sizing. If you are pulling in three things, regardless of what's inside the things use the more than two conductor sizing. The geometry problem doesn't depend on what's inside the thing you are pulling in, just the size and quantity of the things that you are pulling in.