inspector23
Senior Member
- Location
- Temecula, CA
I am looking for clarification of 2002 NEC Article 680.10 - (Underground Wiring Locations), on page 526.
The article states " Underground wiring shall not be permitted under the pool or within the area extending 1.5 m (5ft.) horizontally from the inside wall of the pool unless this wiring is necessary to supply pool equipment permitted by this article. Where space limitations prevent wiring from being routed a distance 1.5 m (5ft) or more from the pool. such wiring shall be permitted where installed in rigid metal conduit, intermediate metal conduit, or a nonmetallic raceway system. All metal conduit shall be corrosion resistant and suitable for the location. The minimum burial depth shall be as given in table 680.10."
The table 680.10 lists nonmetallic raceways listed for direct burial without concrete encasement as 18 inches.
My questions are:
1. What is the NEC definition of encasement? I did not find it in either the general definitions or those definitions specifically for Article 680. Does laying in the bottom of the trench, getting covered in concrete, constitute "encasement"?
2. If you do indeed consider this "encasement", then what is the correct burial depth for the nonmetallic raceway? It is not listed in Table 680.10
3. Why 18 inches for nonmetallic ? If the trench area is getting filled and a 4" slab of concrete poured over it, why is that not sufficient protection for the raceway?
4. If the wiring is not specifically used for the pool equipment, I interpret the article to say the conduit is not allowed if it can indeed be placed further than 5 ft from the inside edge of the pool. Is that a correct assessment?
Any enlightenment be greatly appreciated.
The article states " Underground wiring shall not be permitted under the pool or within the area extending 1.5 m (5ft.) horizontally from the inside wall of the pool unless this wiring is necessary to supply pool equipment permitted by this article. Where space limitations prevent wiring from being routed a distance 1.5 m (5ft) or more from the pool. such wiring shall be permitted where installed in rigid metal conduit, intermediate metal conduit, or a nonmetallic raceway system. All metal conduit shall be corrosion resistant and suitable for the location. The minimum burial depth shall be as given in table 680.10."
The table 680.10 lists nonmetallic raceways listed for direct burial without concrete encasement as 18 inches.
My questions are:
1. What is the NEC definition of encasement? I did not find it in either the general definitions or those definitions specifically for Article 680. Does laying in the bottom of the trench, getting covered in concrete, constitute "encasement"?
2. If you do indeed consider this "encasement", then what is the correct burial depth for the nonmetallic raceway? It is not listed in Table 680.10
3. Why 18 inches for nonmetallic ? If the trench area is getting filled and a 4" slab of concrete poured over it, why is that not sufficient protection for the raceway?
4. If the wiring is not specifically used for the pool equipment, I interpret the article to say the conduit is not allowed if it can indeed be placed further than 5 ft from the inside edge of the pool. Is that a correct assessment?
Any enlightenment be greatly appreciated.
