I. General
353.1 Scope. This article covers the use, installation, and construction specifications for high density polyethylene (HDPE) conduit and associated fittings.
FPN: Refer to Article 352 for Rigid Polyvinyl Chloride Conduit: Type PVC and Article 355 for Reinforced Ther- mosetting Resin Conduit: Type RTRC.
353.2 Definition.
High Density Polyethylene (HDPE) Conduit A nonme- tallic raceway of circular cross section, with associated couplings, connectors, and fittings for the installation of electrical conductors.
353.6 Listing Requirements. HDPE conduit and associ- ated fittings shall be listed.
II. Installation
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.
353.12 Uses Not Permitted. HDPE conduit shall not be used under the following conditions:
(1) Where exposed
(2) Within a building
(3) In any hazardous (classified) location, except as permitted by other articles in this Code
(4) Where subject to ambient temperatures in excess of
50°C (122°F) unless listed otherwise
(5) For conductors or cables operating at a temperature higher than the HDPE conduit listed operating tem- perature rating
Exception: Conductors or cables rated at a temperature higher than the HDPE conduit listed temperature rating shall be permitted to be installed in HDPE conduit, pro- vided they are not operated at a temperature higher than the HDPE conduit listed temperature rating.
353.20 Size.
(A) Minimum. HDPE conduit smaller than metric desig- nator 16 (trade size Vi) shall not be used.
(B) Maximum. HDPE conduit larger than metric designator 155 (trade size 6) shall not be used.
FPN: The trade sizes and metric designators are for identification purposes only and do not relate to actual dimensions. See 300.1(C).
353.22 Number of Conductors. The number of conduc- tors shall not exceed that permitted by the percentage fill specified in Table 1, Chapter 9.
Cables shall be permitted to be installed where such use is not prohibited by the respective cable articles. The number of cables shall not exceed the allowable percentage fill specified in Table 1, Chapter 9.