smalltime
Member
- Location
- Roanoke, VA
This is my understanding... Please clarify and/or adjust any misunderstanding that I may have.
To begin, what I'm dealing with are the conduits and their conductors inside those conduits in a concrete slab on grade.
From the NEC definition:
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.
That’s the definition. My conduit and their floor boxes in concrete in contact with the earth (ground floor location), are considered to be in a wet location.
With the definition, the Code Handbook provides this additional commentary:
The inside of a raceway is a wet location and a raceway installed underground are considered wet locations. Therefore, any conductors contained therein would be required to be suitable for wet locations.
See 300.6(D) for some examples of wet locations...
If I read this correctly, whether it's EMT or PVC makes no difference. Inside these conduits are considered to be in a wet location.
The beginning of 300.6 says this:
Protection Against Corrosion and Deterioration
Raceways, cable trays, cablebus, auxiliary gutters, cable armor, cable sheathing, cabinets, elbows, couplings, fittings, supports, and support hardware shall be of materials suitable for the environment in which they are to be installed.
So if I install conductors in a conduit that's considered to be in a "Wet Location", the cable sheathing (the outside jacket) must also be rated for a "Wet Location."
310.8 (C) appears to confirm this:
Wet Locations. Insulated conductors and cables used in wet locations shall comply with one of the following:
(1) Be moisture-impervious metal-sheathed.
(2) Be types MTW, RHW, yada yada yada.
(3) Be of a type listed for use in wet locations.
So whether it's 120 V or CAT 5 or whatever, the conductors and cabling in conduit in concrete in contact with the earth must be rated for wet locations.
Is this correct or what am I missing?
To begin, what I'm dealing with are the conduits and their conductors inside those conduits in a concrete slab on grade.
From the NEC definition:
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.
That’s the definition. My conduit and their floor boxes in concrete in contact with the earth (ground floor location), are considered to be in a wet location.
With the definition, the Code Handbook provides this additional commentary:
The inside of a raceway is a wet location and a raceway installed underground are considered wet locations. Therefore, any conductors contained therein would be required to be suitable for wet locations.
See 300.6(D) for some examples of wet locations...
If I read this correctly, whether it's EMT or PVC makes no difference. Inside these conduits are considered to be in a wet location.
The beginning of 300.6 says this:
Protection Against Corrosion and Deterioration
Raceways, cable trays, cablebus, auxiliary gutters, cable armor, cable sheathing, cabinets, elbows, couplings, fittings, supports, and support hardware shall be of materials suitable for the environment in which they are to be installed.
So if I install conductors in a conduit that's considered to be in a "Wet Location", the cable sheathing (the outside jacket) must also be rated for a "Wet Location."
310.8 (C) appears to confirm this:
Wet Locations. Insulated conductors and cables used in wet locations shall comply with one of the following:
(1) Be moisture-impervious metal-sheathed.
(2) Be types MTW, RHW, yada yada yada.
(3) Be of a type listed for use in wet locations.
So whether it's 120 V or CAT 5 or whatever, the conductors and cabling in conduit in concrete in contact with the earth must be rated for wet locations.
Is this correct or what am I missing?
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