conduit sizing

[deepthreat]

I am wondering if my calculation aptitude for sizing conduit is up to snuff.

If I have 6 4/0 thhn conductors and 2 1/0 thhn conductors and want to use schedule 80 pvc conduit.

From Chapter 9, Table 5: sq in area for 4/0 is; 0.3237(6)=1.9422
sq in area for 1/0 is; 0.1855(2)=0.371

Total sq in area calculated;
1.9422+0.371=2.3132

From Chapter 9, Table 4: Art. 352 sched 80 pvc conduit
over 2 wires
40%

2 1/2" @ 1.674 sq in. is too small
3" @ 2.577 sq in. is necessary

Is that the proper method of calculating condiut size? Just checking questions I remember from a test I took Saturday. Thanks in advance for any input.

 

[LarryFine]

According to this handy-dandy fill calculator I found, 3" is correct.

http://jlgengsoft.com/Documents/fill.htm

Enter sizes and quantities, then hit 'calculate'.

 

[hardworkingstiff]

I'd say you have a good understanding of the methodology used to determine the minimum conduit size. Depending on the length of a run, I sometimes will up a size.

 

[roger]

I agree with Lou, I would say you have it.

Roger