300 mcm how many in conduit per nec code

[ohmhead]

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

 

[480sparky]

What size of PVC?

 

[Volta]

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.

 

[ohmhead]

What size of PVC?

GEEZ 480 i forgot the most important thing 2 1/2 inch now pvc sch 40 .

 

[480sparky]

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.

 

[Dennis Alwon]

GEEZ 480 i forgot the most important thing 2 1/2 inch now pvc sch 40 .

four-- check Table C-10 in Annex C

 

[iwire]

I will trust Ken's figures and go with 5.

 

[480sparky]

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."

 

[Dennis Alwon]

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."

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]

So why is it there. .......

Heck if I know. There's a lot of stuff in the NEC I can't explain.

 

[Dennis Alwon]

Ken I still get 4-- check my math

300 mcm xhhw-2 = .4536
2 1/2" PVC sced. 40= 1.878

1.878/.4536= 4.14

 

[Volta]

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.

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.

four-- check Table C-10 in Annex C

Occasionally those non-Code tables are wrong, but four is correct here.

 

[iwire]

Ken I still get 4-- check my math

300 mcm xhhw-2 = .4536
2 1/2" PVC sced. 40= 1.878

1.878/.4536= 4.14

Dennis did you get that area from the right table, it is a compact AL conductor.

 

[Volta]

I will trust Ken's figures and go with 5.

Don't do it :grin:.

 

[Dennis Alwon]

Dennis did you get that area from the right table, it is a compact AL conductor.

I missed the compact aluminum-- thanks

 

[480sparky]

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.

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

......Also, 2-1/2 schedule 40 available area is not 2.181, you are looking at Type A..........

So I'm not smarter than a 5th grader. 1.878 / 0.3904 = 4.48.

 

[Dennis Alwon]

Got it..... but it is still 4 wires. and its 4.8

 

[480sparky]

Not let's let the other shoe hit the floor.:roll:

Got it..... but it is still 4 wires. and its 4.8

I gotta learn to push the right buttons on my calculator.

 

[Dennis Alwon]

Not let's let the other shoe hit the floor.:roll:

:grin: I would hate to pull that run with just 4 conductors.

 

[480sparky]

:grin: I would hate to pull that run with just 4 conductors.

Supposin' four is all you need?