300 mcm how many in conduit per nec code

Status
Not open for further replies.
ohmhead

ohmhead

Senior Member
Location
ORLANDO FLA
Well question for the experts how many 300 mcm xhhw-2 in pvc sch 40 conduit can we install think about it good ? I have another question after any responses.

That compact alu wire also
 
PIPE - WIRES
1 --- 1
1.5 - 1
2 --- 3
2.5 - 4
3 --- 7
3.5 - 9
4 --- 12
5 --- 19
6 --- 28

More for nipples. This is for XHHW compact in PVC 40.
 
Last edited:
I come up with 5, using Alcan's dimensions. YMMV.

2?" PVC @ 40% fill is 2.181 in?. Dimension given is .3904 in?. 2.181 / 0.3904 = 5.58.

So 5. Final answer. I'm locking it in.
 
352.22 Number of Conductors.
The number of conductors shall not exceed that permitted by the percentage fill specified in Table 1, Chapter 9. C-10 is not mentioned.

Read the beginning of those tables.:
"This annex is not a part of the requirements of this NFPA document but is included for informational purposes only."
 
480sparky said:
352.22 Number of Conductors.
The number of conductors shall not exceed that permitted by the percentage fill specified in Table 1, Chapter 9. C-10 is not mentioned.

Read the beginning of those tables.:
"This annex is not a part of the requirements of this NFPA document but is included for informational purposes only."
Click to expand...

So why is it there. I thought that was to save time and not have to calculate but I see that's wrong. Thanks.
 
480sparky said:
I come up with 5, using Alcan's dimensions. YMMV.

2?" PVC @ 40% fill is 2.181 in?. Dimension given is .3904 in?. 2.181 / 0.3904 = 5.58.

So 5. Final answer. I'm locking it in.
Click to expand...
Note 6 of Chapter 9 allows actual dimensions to be used for conductors not included in Chapter 9. However XHHW compact is listed in Table 5A as having an area of .4015 in sq., not .3904.

Also, 2-1/2 schedule 40 available area is not 2.181, you are looking at Type A.
:)
Dennis Alwon said:
four-- check Table C-10 in Annex C
Click to expand...

Occasionally those non-Code tables are wrong, but four is correct here.
 
Volta said:
Note 6 of Chapter 9 allows actual dimensions to be used for conductors not included in Chapter 9. However XHHW compact is listed in Table 5A as having an area of .4015 in sq., not .3904.
Click to expand...

It's XHHW-2 in the OP, not XHHW. That's why I used a manufacturer's spec.

Volta said:
......Also, 2-1/2 schedule 40 available area is not 2.181, you are looking at Type A..........
Click to expand...

So I'm not smarter than a 5th grader. 1.878 / 0.3904 = 4.48.
 
Last edited:
Status
Not open for further replies.
Top