ART. 353

[Rudy Maio]

Art. 353 II installation 353.10 uses permitted.Type HDPE Conduit (4) In direct installations in earth or concrete.

Art. 300.50 (A) (2) Other Non shielded cables. Other non sheilded cables not covered in 300.50(A)(1) shall be installed

in rigid metal conduit, intermediate metal conduit or rigid metal conduit encased in not less than 3 in. of concrete.

Ques. I am installing HDPE underground. I will be installing conductors that will operate at 13.2KV. RMC, IMC and Sch 80 PVC

are all permitted for direct burial as is HDPE. Why is it that HDPE does not have to be incased in concrete. for this installation

or does it?Also, if it's not required to be incased in concrete how do we comply with Table 300.50 general note d which requires

a warning ribbon. remember this HDPE was not trenched in but bored in. I can't imagine a conduit containing conductors operating at

13.2 KV not being concrete encased. Thank You

 

[don_resqcapt19]

Note d does not apply to cables or conductors in a raceway. It only applies to directly buried cables.
If you are not using a cable that has a metallic jacket, it appears that you can't use HDPE. I don't see that as a rigid non-metallic conduit. If it is a rigid non-metallic conduit, then you would have to encase it in 3" or more of concrete.