I must agree with the previous posts and add that in a discussion with another member, Russ M, he wrote :
This is out of the UL white book.
In general, galvanized steel electrical metallic tubing in contact with soil requires supplementary corrosion protection. Where galvanized steel electrical metallic tubing without supplementary corrosion protection extends directly from concrete encasement to soil burial, severe corrosive effects are likely to occur on the metal in contact with the soil.
Supplementary nonmetallic coatings presently used have not been investigated-
for resistance to corrosion.
I was looking for his opinion as a fellow inspector. It confirmwed mine, and since Russ has been doing this far longer than I, I was confident that he had the resources for substantiation,
I hope it helps.
Gregg
