under slab conduit in dentist office

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tyha

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does the conduit in a dentist office going btween the wall and the center console for equipment need to be rigid if its under slab
 
I agree with rcarroll.

The conduits run in the slab that supply equipment in the patient care area of a dentist office must comply with 517.13.

Chris
 
does the conduit in a dentist office going btween the wall and the center console for equipment need to be rigid if its under slab
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Yes. I couldn't believe my eyes when I first read this several years ago. Absolutely stupid in my opinion. You want a 100% failsafe ground? Conduit aint it.
 
For all practical pupose, especialy in this discussion, IMC = RMC.


EMT under slab isn't allowed in all areas (like here). I was quite surprised to learn that NEC allows it.

RMC/IMC doesn't last long underground here either, even when it's pipe wrapped.
 
IMO the inside of the PVC would be a wet location which would prohibit the use of AC cable.
 
infinity said:
IMO the inside of the PVC would be a wet location which would prohibit the use of AC cable.
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If the PVC went "under" the slab I would agree....But if the PVC is "in" the slab and the slab is inside the building, How could it be considered a wet location?
 
Patient care

Patient care

If it is a patient care area you can use any metallic raceway listed for the application. MC , Rigid metallic, EMT , Imc , .
GOOD LUCK !!
Keep reading it until you understand. Eventually you will see the light.
 
Chris6245 said:
If the PVC went "under" the slab I would agree....But if the PVC is "in" the slab and the slab is inside the building, How could it be considered a wet location?
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Even a conduit within the concrete would be a wet location if that concrete was in direct contact with the earth. I agree that a conduit in a slab on a floor that is not in contact with the earth wouldn't be a wet location.

Location, Wet. Installations underground or in concrete slabs or masonry in direct contact with the earth; in locations subject to saturation with water or other liquids, such as vehicle washing areas; and in unprotected locations exposed to weather.
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infinity said:
Even a conduit within the concrete would be a wet location if that concrete was in direct contact with the earth. I agree that a conduit in a slab on a floor that is not in contact with the earth wouldn't be a wet location.
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I agree with this and if I had my book I would give you the code article.
 
Dennis Alwon said:
I agree with this and if I had my book I would give you the code article.
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Here is the definition of wet location:

Location, Wet. Installations underground or in concrete slabs or masonry in direct contact with the earth; in locations subject to saturation with water or other liquids, such as vehicle washing areas; and in unprotected locations exposed to weather.
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Chris
 
I had one where the EC ran RMC in slab and stubbed up below chair. The EC pulled HCF MC should a bond bushing be installed on the RMC stub up below the chair? Yes the MC was pvc coated.
 
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dcspector said:
I had one where the EC ran RMC in slab and stubbed up below chair. The EC pulled HCF MC should a bond bushing be installed on the RMC stub up below the chair? Yes the MC was pvc coated.
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Pretty expensive run, IMO
I say if the MC is rated for wet location & the sheathing is a ground path, which apparenly it is, no bond bushing required.
 
raider1 said:
Here is the definition of wet location:



Chris
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OK....But what is between the concrete and "earth" 90% of the time? (at least in my area of the country) Pea Gravel and Visqueen...So is the concrete in "DIRECT CONTACT" with the earth? IMO no. Around here (Ohio) I very rarely see concrete poured directly on dirt.
 
Chris6245 said:
OK....But what is between the concrete and "earth" 90% of the time? (at least in my area of the country) Pea Gravel and Visqueen...So is the concrete in "DIRECT CONTACT" with the earth? IMO no. Around here (Ohio) I very rarely see concrete poured directly on dirt.
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I agree that if there is plastic under the slab then the slab is not in direct contact with the earth ............ That said, it is not a hair I would leave to split with the inspector, I would treat it as a wet location and use suitable conductors in it.
 
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