Underground Conduit - Encase or Direct Burial? (NEC 300.5)

Discussion created by kedwindominguez on May 17, 2017
Latest reply on Jun 27, 2017 by paul.abernathy

Design scenario:

Conduit has to be installed from a pad mount transformer secondary to a electrical room (MCC).  In between has no traffic and is a industrial location.  



Applicable Code (NEC 2014)


According to 300.5 

(C) Underground Cables and Conductors Under Buildings.
Underground cable and conductors installed under a building
shall be in a raceway.


According to Table 300.5 Note 2

2. Raceways approved for burial only where concrete encased shall require concrete envelope not less than
50 mm (2 in.) thick.


My questions is:

  • If conduit is installed underground, is it safe to assume the conduit will always be concrete encased? if not, when would be the exception?


Thank you for your assistance,


Kedwin Dominguez