NEC section 353

[astpeter]

Why is HDPE conduit not allowed above ground?

 

[Dennis Alwon]

Why is HDPE conduit not allowed above ground?

Who says it is not allowed above ground? The 2008 NEC has added 353.1210(5) but that just appears to me to help clarify the existing code. Being as I never have used this stuff I am really just guessing. Maybe the bump up will help get other responses.

353.10 Uses Permitted.
The use of HDPE conduit shall be permitted under the following conditions:
(1) In discrete lengths or in continuous lengths from a reel
(2) In locations subject to severe corrosive influences as covered in 300.6 and where subject to chemicals for which the conduit is listed
(3) In cinder fill
(4) In direct burial installations in earth or concrete
FPN to (4): Refer to 300.5 and 300.50 for underground installations.
(5) Above ground, except as prohibited in 353.12, where encased in not less than 50 mm (2 in.) of concrete.

 

[benaround]

Why is HDPE conduit not allowed above ground?

It is simply designed for underground use only, with an ambient temp of 50c or less.

 

[Dennis Alwon]

It is simply designed for underground use only, with an ambient temp of 50c or less.

Frank It states for above ground use in 353.10...:-?

 

[don_resqcapt19]

Frank It states for above ground use in 353.10...:-?

Sort of...it is only permitted above ground where encased in 2" of concrete.

(5) Above ground, except as prohibited in 353.12, where encased in not less than 50 mm (2 in.) of concrete.