Aren’t manufacturers required to use Underwriters Laboratories (UL) for their compliance testing? Isn’t this mandated by the standards?
1,The answer is no. The standards such as UL 651 specify what requirements a product must meet and do not have any requirements for certification. 2, The 2014 edition of the National Electrical Code (NEC) Section 352.6 states “Listing Requirements. PVC conduit, factory elbows, and associated fittings shall be listed.” No listing agency is specified. 3, The listing can be provided by any OSHA approved NRTL. A Nationally Recognized Testing Laboratory (NRTL) is an independent laboratory recognized by the Occupational Safety and Health Administration (OSHA) to test products to the specifications of applicable products standards such as UL 651. A NRTL function is to provide an independent evaluation, testing, and certification of a product. 4, Intertek (ETL), NSF International, and Underwriters Laboratories are NRTL’s. For more information go to osha.gov.
1, The answer is yes. 2, Paragraph 1.2.1 of UL 651 states “Schedule 40 rigid PVC conduit and fittings are for above ground use indoors or outdoors exposed to sunlight and weather and for underground uses by direct burial or encasement in concrete. 3, Para 1.2.1 of UL 651 states Schedule 80 rigid conduit and fittings are for use wherever Schedule 40 rigid PVC conduit may be used. 4, For allowable installations and restriction see 2014 NEC Article 352.
1, Schedule 40 and 80 conduit – NEMA TC-2 Electrical Polyvinyl Chloride (PVC) Conduit 2, EB and DB duct – NEMA TC 6 and 8 Polyvinyl Chloride (PVC) Plastic Utilities for Underground Installation 3, Fabricated Fittings NEMA TC-3 Polyvinyl Chloride (PVC) Fittings for Use with Rigid PVC Conduit and Tubing.
1, Paragraph 1.2.1 of UL 651 states “Schedule 40 rigid PVC conduit and fittings are for above ground use indoors or outdoors exposed to sunlight and weather and for underground uses by direct burial or encasement in concrete. 2, Para 1.2.1 of UL 651 states Schedule 80 rigid conduit and fittings are for use wherever Schedule 40 rigid PVC conduit may be used and are for installation on poles in accordance with the National Electrical Code (NEC), NFPA 70. 3, The Schedule 40 and 80 conduit and fabricated fittings are “Sunlight Resistant” for UL 651
The conduit and fitting meet UL 651 para. 6.11 Flame test requirements.
As directed by the NEC, Section 347-3(c), Schedule 80 is to be used in areas of possible damage such as impact or crush.
Schedule 40 electrical conduit is not recommended for the transmission of water or gas.
The maximum ambient use temperature is 50°C (122°F). The minimum installation temperature is -20°C (-4°F).
Federal Specification W-C-1094 canceled September 13, 1985. It was replaced with the following specifications: UL 514B, UL 514C, UL 651 and UL 651A. Heritage Plastics Sch. 40 and SCH. 80 PVC conduits meet UL 651 and therefore meet the discontinued specification W-C-1094 (A). These standards have been adopted by GSA-FSS and DoD.