poured walls/wet locations. imbedded boxes. code question.

[bstacy]

I had a an employee propose a novel installation strategy that would save money, but cannot confirm if this is in violation. the scenario:
a waste water pump room considered to be in a wet location. We are laying out the design currently. The electrician has proposed that we run conduit to a masonry box, imbedded in the wall during the poor. this will save us on needing to run pvc coated rigid. a gasketed cover plate (wet location) with a 3/4 ko will be installed allowing for a seal-tight whip to the disconnect. my concern is that the cover plate is rated for wet locations the the masonry box is not. is this a legal installation????

 

[tom baker]

I have seen that done in a water treatment plant, PVC conduit in the walls, with PVC box sticking out of wall. The all PVC conduit on surface in the hypo room. It worked well.
My concern with your installation is the masonry box would corrode over time. I would consider using a SS box, or PVC. Anything in the wall can't be easily replaced, need to think 20-30 years down the road

 

[jap]

If your concerned about the box in the wall, why not offset the pipe out of the form and land the disconnect on top of the stubout?
or,
Stub up just outside the base of the wall just below where the disconnect is going to be mounted making for a short stubup of Robroy if needed?


JAP>

 

[electrofelon]

I had a an employee propose a novel installation strategy that would save money, but cannot confirm if this is in violation. the scenario:
a waste water pump room considered to be in a wet location. We are laying out the design currently. The electrician has proposed that we run conduit to a masonry box, imbedded in the wall during the poor. this will save us on needing to run pvc coated rigid. a gasketed cover plate (wet location) with a 3/4 ko will be installed allowing for a seal-tight whip to the disconnect. my concern is that the cover plate is rated for wet locations the the masonry box is not. is this a legal installation????

I think it's fine. No different than cutting in a cut in box on the outside of a house and putting an in use or flap cover over it. I would however also have some concern about the longevity of the box.

 

[jap]

I think it's fine. No different than cutting in a cut in box on the outside of a house and putting an in use or flap cover over it. I would however also have some concern about the longevity of the box.

This is a little more entailed than simply cutting in a box on the outside of a house and putting a flap cover on it.

Evidently this is a live pour project where the stubup will have to be roughed in, the box preinstalled inside the form with the face of the box mated to the inside of the form all the while maintaining it's integrity during the pour.

There's a lot more room for error on these type of live pour projects.

JAP>

 

[electrofelon]

This is a little more entailed than simply cutting in a box on the outside of a house and putting a flap cover on it.

Evidently this is a live pour project where the stubup will have to be roughed in, the box preinstalled inside the form with the face of the box mated to the inside of the form all the while maintaining it's integrity during the pour.

There's a lot more room for error on these type of live pour projects.

JAP>

Sure the construction is more involved, but the theory is the same.

 

[roger]

Have done it many times in poured walls be it Simon's type forms or stand up type construction. On the latter we would rough them in on the ground and turn a 90 out at joist level.

Roger