UL 6703-2021 pdf download – Connectors for Use in Photovoltaic Systems.
6 Polymeric Materials 6.1 General 6.1.1 Polymeric materials may be used as an enclosure or as insulating materials that are in direct contact with or in close proximity, less than 0.8 mm (1/32 in), to live parts. When the same material is used for both purposes, the more stringent requirements shall be applied. 6.1.2 Polymeric materials employed as a part of the connector shall be suitable for its rated temperature. The relative thermal index (RTI), electrical, mechanical impact (IMP) and mechanical strength (STR), as determined in accordance with the Standard for Polymeric Materials – Long Term Property Evaluations, UL 746B, shall not be less than 20° C (36° F) above the maximum operating temperature rating for the connector as specified by the manufacturer. For soft materials, such as elastomers, where the RTI Mechanical IMP cannot be determined, or for those connectors protected from impact under use, the RTI mechanical IMP is not required. 6.1.3 A polymeric material serving as the enclosure of a part involving a risk of fire or electric shock shall comply with the applicable requirements in the Standard for Polymeric Materials – Use in Electrical Equipment Evaluations, UL 746C, concerning: a) Ultraviolet light exposure, and Note: An f1 rating signifies compliance, an f2 rating requires further investigation into its suitability. b) Water exposure and immersion. 6.1.4 A polymeric material serving as the enclosure shall have a minimum flammability classification of V-0 or 5VA as determined by tests described in the Standard for Tests for Flammability of Plastic Materials for Parts in Devices and Appliances, UL 94. The material thickness for determining the flammability shall be measured at the thinnest points of the enclosure. 6.1.5 With reference to 6.1.4, a material other than V-0 or 5VA may be used when the enclosure of the PV wire connector complies with the requirements for the equivalent flame test as specified in the Standard for Polymeric Materials – Use in Electrical Equipment Evaluations, UL 746C.