UL 651A:2017 PDF Download

The UL 651A:2017 standard specifies the requirements for straight conduit and coilable, smooth-wall, continuous length conduit with a circular cross-section.

The standard covers various materials such as extruded straight rigid Schedule 40 high density polyethylene (PE) conduit, as well as fittings such as elbows and rigid PE couplings designed for use with this conduit type. It also covers coilable, smooth-wall continuous length high density PE conduit types, including Schedule 40, Schedule 80, EPEC-A, and EPEC-B.

The conduit and fittings covered in this standard are intended for use at ambient temperatures of 50°C (122°F) and lower. However, straight rigid Schedule 40 conduit and fittings may be used with 90°C (194°F) wiring if directly buried or encased in concrete in trenches outside of buildings.

These conduit types and fittings are specifically designed to be used as rigid nonmetallic raceways for wires and cables, in accordance with the National Electrical Code (NFPA 70).

Extruded straight rigid Schedule 40, Schedule 80, EPEC-A, and EPEC-B coilable conduit can be used aboveground if encased in at least 2 inches (50 mm) of concrete, and can also be used underground by direct burial or encasement in concrete.