Pull Box Sizing

[rochaconstruct]

While on an inspection I wrote up a 6x6 box with an 1 1/2" conduit running in the top and out the bottom (straight pull 314.28.A.1 8 times) the box should be 12".
I understand the box should be sized for the conductors.
There were several conductors running through the conduit all low voltage, one of the low voltage conductors was about the size of a 4/0 the others about the size of a # 8 or smaller.
When the engineer read my report he called and said that this article only applies to power not low voltage. I on the otherhand believe it applies to everything.
Have I been wrong all these years.

 

[infinity]

IMO the engineer was correct, the 8X rule does not apply to these conductors.

 

[nakulak]

I don't recall a code article entitled "low voltage". however, if the wiring method is class 2 or 3 and article 725, 800, 820, etc apply, then the requirements of chapter 3 would not seem to apply to the installation. If the wiring method is a chapter 3 method or class 1, then I would think that the 8x rule would apply. jmso

 

[chipster]

Pull box sizing

Pull box sizing

Is there a way to relocate this thread from Electrical Calcs/Eng. to NEC?

 

[infinity]

If you look at 314.28(A) the minimum size for the 8X dimension to become applicable is #4 AWG in a raceway or cable. Did the cable contain a conductor #4 or larger?

 

[rochaconstruct]

I believe the conduit in chapter 3 is the same used in 725 or any other chapter

 

[rochaconstruct]

As i stated before they were all low voltage cables (<50v) but at least 1 was a lot larger in diameter than a #4

 

[Pierre C Belarge]

While on an inspection I wrote up a 6x6 box with an 1 1/2" conduit running in the top and out the bottom (straight pull 314.28.A.1 8 times) the box should be 12".
I understand the box should be sized for the conductors.
There were several conductors running through the conduit all low voltage, one of the low voltage conductors was about the size of a 4/0 the others about the size of a # 8 or smaller.
When the engineer read my report he called and said that this article only applies to power not low voltage. I on the otherhand believe it applies to everything.
Have I been wrong all these years.

I believe he is correct. Depending on which Article, Chapter 8 has to have a section number specifically referenced for that portion to be applicable.

I do not see where 314.28 is referenced.
I am guessing the low voltage wiring is from one of those Articles.

 

[JFletcher]

What exactly is the cable type? 314.28(A) does not apply to most, if not all, communications cable - its conductors are substantially smaller than 4ga, regardless of the OD.

Pierre, 800.110 references chapter 3 in its entirety.

 

[infinity]

As i stated before they were all low voltage cables (<50v) but at least 1 was a lot larger in diameter than a #4

The outer diameter of the cable doesn't matter if the cable contains conductors smaller than #4 AWG.

 

[iwire]

I believe the conduit in chapter 3 is the same used in 725 or any other chapter

Of course the conduit is the same but the rules are not.

As i stated before they were all low voltage cables (<50v) but at least 1 was a lot larger in diameter than a #4

Are you saying a 'multicondutor cable' was larger than a #4?

If so that makes no diffrence unless one of the condutors on tha cable is larger than 4 AWG.

 

[infinity]

Is there a way to relocate this thread from Electrical Calcs/Eng. to NEC?

I merged this and a duplicate thread together here. If anyone is wondering I forgot to leave a redirect in the other forum. :roll:

 

[JFletcher]

I merged this and a duplicate thread together here. If anyone is wondering I forgot to leave a redirect in the other forum. :roll:

Ah! I was wondering where all of those other posts came from.