Minimum conduit depth in concrete

[JOECOL]

In a manufacturing plant. Have a pushbutton station to install and would like to take up 3" floor block that sits on concrete slab layin 3/4" conduit and cover with concrete. Only foot traffic in area. Would only be about 2" deep. Will this satify the NEC?

 

[MasterTheNEC]

@JOECOOL-

While I am sure I will get flamed for this...lol....I know that it is technically not under the building as defined in T300.5, and we also know that nothing would require you to actually bury it in the first place other than to avoid physical damage. To be honest with you I would permit it (as the AHJ) as the concrete is the actual floor and your company has chosen to apply a 3" floor covering which is obviously removable...to which now you are going to be encasing the conduit in with the finished concrete floor, I would have no issues with the installation.

However- be prepared for other opinions on that.

 

[Chrispacc]

Yes, check out 300.5 chart (Under a building) 0" deep no matter what type of conduit it is.

 

[MasterTheNEC]

Yes, check out 300.5 chart (Under a building) 0" deep no matter what type of conduit it is.

Is it under the building.....?????? they are removing surface blocks and laying it on the concrete slab. I would contend it is not under the building.

 

[petersonra]

Is it under the building.....?????? they are removing surface blocks and laying it on the concrete slab. I would contend it is not under the building.

I don't see how it is "under" the building either.

I also do not think it is "underground", so table 300.5 does not appear to be relevant.

 

[MasterTheNEC]

I don't see how it is "under" the building either.

I also do not think it is "underground", so table 300.5 does not appear to be relevant.

:thumbsup:

 

[JOECOL]

MIN DEPTH

MIN DEPTH

So if your conduit is embedded in concrete inside a manufacturing building. Where in NEC 2014 does it give you depth requirements? Or where in the code does it tell you there are no requirements?

 

[Dennis Alwon]

I think Table 300.5 does tell us. I think 2" is what is required

 

[cowboyjwc]

For nonmetallic it's 4" of cover with no vehicular traffic and the slab extending not less than 6" beyond the installation

Rigid and intermediate is the same thing.

Now my guess would be that most inspectors wouldn't really care too much if it's in a building with only foot traffic I would say what you are doing thinking of would be fine.

 

[infinity]

In a poured slab within the building there is not minimum cover depth. A shallow grove with the conduit installed and patched is all that's needed.

 

[electricalist]

I would want to run ridged on the floor and put a raised floor in that area.

 

[iwire]

In a poured slab within the building there is not minimum cover depth. A shallow grove with the conduit installed and patched is all that's needed.

I agree 100%.

 

[Fulthrotl]

In a poured slab within the building there is not minimum cover depth. A shallow grove with the conduit installed and patched is all that's needed.

yep. run GRC, tape it so it doesn't corrode, cut a groove, put it in, and grout it.

 

[electricalist]

yep. run GRC, tape it so it doesn't corrode, cut a groove, put it in, and grout it.

A grinder with a concrete wheel works great

I agree 100%.