UL - 651
UL Standard for Safety Schedule 40 and 80 Rigid PVC Conduit
|Publication Date:||17 August 1995|
These requirements cover Schedule 40 and Schedule 80 extruded rigid PVC (polyvinyl chloride) electrical conduit, and fittings consisting of elbows and other bends made from and for use with this conduit. The designations "Schedule 40" and "Schedule 80" refer to USA trade sizes of conduit having iron-pipe-size outside diameters and specific wall thicknesses.
The following restrictions apply to use of the PVC conduit and fittings mentioned in 1.1:
a) Use at 50 degrees C (122 degrees F) and lower ambient temperatures
b) Use with 75 degrees C (167 degrees F) wiring, but the conduit and fittings may be used with 90 degrees C (194 degrees F) wiring if they comply with the construction (see Conduit for Use with 90 degrees C Wire, Section 16) and marking (see 20.3 and 20.7 - 20.8) requirements covering use with 90 degrees C (194 degrees F) wiring.
The conduit and fittings covered in these requirements are intended for use as rigid nonmetallic raceway for wires and cables in accordance with the National Electrical Code.
Schedule 40 rigid PVC conduit and fittings are for aboveground use indoors or outdoors exposed to sunlight and weather, and for underground
use by direct burial or encasement in concrete.
Exception: Schedule 40 rigid PVC conduit, elbows, and other bends,
marked in accordance with 20.9 are suitable for use only underground
by direct burial or encasement in concrete.
1.4 revised October 16, 1998
Schedule 80 rigid PVC conduit and fittings are for use wherever Schedule
40 rigid PVC conduit may be used and, in addition, are for installation
on poles in accordance with the National Electrical Code.
Type EB and Type A rigid PVC electrical conduit and fittings consisting
of elbows and other bends made from and for use with this conduit are covered separately in the Standard for Type EB and A Rigid PVC Conduit
and HDPE Conduit, UL 651A.
Unless the wording of a requirement specifically limits the requirement
to Schedule 40 or to Schedule 80, each requirement in this standard applies to both schedules.
Conduit bodies (pull boxes) and covers, flush-device boxes and covers, and outlet boxes and covers that are of rigid PVC or another nonmetallic material and are for use with the rigid PVC conduit and fittings covered in these requirements are covered separately in the Standard for
Nonmetallic Outlet Boxes, Flush-Device Boxes, and Covers, UL 514C.
Couplings, adapters, expansion joints, and similar fittings that are
of rigid PVC and are for use with the rigid PVC conduit and fittings covered in these requirements are covered separately in the Standard
for Metallic Outlet Boxes, UL 514A.
Reinforced thermosetting resin conduit and associated fittings are
covered separately in the Standard for Reinforced Thermosetting Resin
Conduit (RTRC) and Fittings, UL 1684.
1.10 revised October 16, 1998
The rigid PVC conduit and fittings covered in these requirements are
intended to be joined to rigid PVC boxes, conduit bodies, and fittings in the field by means of a cement that is or contains a solvent for polyvinyl chloride.
Rigid PVC conduit and fittings are inherently resistant to the corrosive influences of common industrial atmospheres including the vapors and mists of bases, hydrofluoric and chromic acids, and pickling and plating baths. Resistance to wetting by and immersion in reagents is covered in
Resistance to Specific Reagents, Section 17, and 20.5 and 20.6.
A product that contains features, characteristics, components,
materials, or systems new or different from those covered by the requirements in this standard, and that involves a risk of fire or of electric shock or injury to persons shall be evaluated using appropriate additional component and end-product requirements to maintain the 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 does not comply with this standard. Revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this standard.