UL 1990

1.1 These requirements cover nonmetallic underground conduit with conductors. These products consist of a factory assembly of conductors or cables inside a coilable, smooth-wall, continuous length conduit with a circular cross section. The conduit is Schedule-40, Schedule-80, EPEC-A or EPEC-B High Density Polyethylene (HDPE) in trade sizes < (16) 4 (103). This product is intended for installation in accordance with the National Electrical Code, NFPA 70. The values in parentheses are metric trade designators o f conduit. The designations Schedule-40, Schedule-80, EPEC-A and EPEC-B refer to conduit having specific outside diameters and wall thicknesses.

1.2 This product is for aboveground use where encased in not less than 2 inches (51 mm) of concrete and for underground use by direct burial or encasement in concrete.

1.3 A product that contains features, characteristics, components, materials, or systems new or different from those cove red by the requirements in this standard, and that involve a risk of fire, electric shock, or injury to persons shall be evaluated using the appropriate additional component and end-product requirements as determined necessary to maintain the acceptable level of safety as originally anticipated by the intent of this standard. A product whose features, characteristics, components, materials, or systems conflict with specific requirements or provisions of this standard cannot be judged to comply with this standard. Where considered appropriate, revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this standard.