Concrete incased conductors w/ >360 deg.

[bfingland]

I have a building whose main electrical room is 2 floors above the utility transformer. The service lateral conductors are routed through building encased in 2" of concrete (230.6). The way it was routed worked fine until a foundation change during construction forced it to be rerouted. To avoid a grade beam under the bottom floor slab, more that 360 degrees of turns in the conduit are required.

Question: if we use a pull box in order to afford a few more turns, would those conductors still be considered outside of the building?

Thanks.

 

[Dennis Alwon]

I have a building whose main electrical room is 2 floors above the utility transformer. The service lateral conductors are routed through building encased in 2" of concrete (230.6). The way it was routed worked fine until a foundation change during construction forced it to be rerouted. To avoid a grade beam under the bottom floor slab, more that 360 degrees of turns in the conduit are required.

Question: if we use a pull box in order to afford a few more turns, would those conductors still be considered outside of the building?

Thanks.

This should answer your question

230.6 Conductors Considered Outside the Building.
Conductors shall be considered outside of a building or other structure under any of the following conditions:
(1) Where installed under not less than 50 mm (2 in.) of concrete beneath a building or other structure
(2) Where installed within a building or other structure in a raceway that is encased in concrete or brick not less than 50 mm (2 in.) thick
(3) Where installed in any vault that meets the construction requirements of Article 450, Part III
(4) Where installed in conduit and under not less than 450 mm (18 in.) of earth beneath a building or other structure

 

[bfingland]

I reference 230.6 in my first post and rereading did not exactly answer my question.

In my situation do you think that a pull box is not allowed since it is not specifically mentioned in 230.6?

 

[winnie]

It seems to me that if the junction box were encased in concrete, that it would meet the requirements of 230.6. However I was under the impression that a junction box needs to remain accessible. I could imagine a removable concrete access cover.....I don't see any requirement that the concrete or brick go right up to the raceway; simply that there be a 2" thick barrier.

-Jon

 

[Dennis Alwon]

I reference 230.6 in my first post and rereading did not exactly answer my question.

In my situation do you think that a pull box is not allowed since it is not specifically mentioned in 230.6?

Sorry-- I thought it was clear. I don't believe a jb would meet the definition of outside the building.

 

[LarryFine]

Keep in mind that the NEC is as much about protecting the building and occupants from the electricity as it is about protecting the conductors from the building and occupants.

The conductors have to be considered outside the building envelope in order for the need for OC and fault to be omitted. This is to protect the building and occupants.

I don't believe a jb would meet the definition of outside the building.

Exactamundo.

 

[Dennis Alwon]

Exactamundo.

I didn't realize you spoke so many languages. :grin:

 

[LarryFine]

I didn't realize you spoke so many languages. :grin:

Mais oui!

 

[Dennis Alwon]

Mais oui!

Sure you may.:grin:

 

[BAHTAH]

Pull Box considered outside building

Pull Box considered outside building

I have a building whose main electrical room is 2 floors above the utility transformer. The service lateral conductors are routed through building encased in 2" of concrete (230.6). The way it was routed worked fine until a foundation change during construction forced it to be rerouted. To avoid a grade beam under the bottom floor slab, more that 360 degrees of turns in the conduit are required.

Question: if we use a pull box in order to afford a few more turns, would those conductors still be considered outside of the building?

Thanks.

You may want to check with the AHJ as 90-4 at least provides for the AHJ to allow a pull box (wavering code requirements). The code would not allow a pull box per 230.6. I would find out what type of pull box is used by the utility company for high-rise buildings. When I worked for a utility we had pull boxes on several floors with support to the vertical cables. Those boxes were not in any special room. I am not sure if they had a 3-hour fire rating or not. Just a thought..

 

[Smart $]

I have a building whose main electrical room is 2 floors above the utility transformer. The service lateral conductors are routed through building encased in 2" of concrete (230.6). The way it was routed worked fine until a foundation change during construction forced it to be rerouted. To avoid a grade beam under the bottom floor slab, more that 360 degrees of turns in the conduit are required.

Question: if we use a pull box in order to afford a few more turns, would those conductors still be considered outside of the building?

Thanks.

Change your pull box idea to a "vault" and you'll be good to go. Qualifies under 230.6(3). See Article 450, Part III for the construciton requirements.