UL-979:2016 pdf free download – STANDARD FOR SAFETY Water Treatment Appliances.
8.8 A polymeric enclosures shall comply with the Standard for Polymeric Materials — Use in Electrical Equipment Evaluations, UL 746C. When determining compliance with UL 746C, the polymeric (including epoxy potting compounds) enclosure shall comply with the following:
a) Material Properties — The material shall comply with the “Material property considerations” in Table 8.1 of UL 746C.
b) Impact Test — A minimum impact of 5 tt-Ibf (6.8 J) shall apply to all enclosure materials. In addition to the test requirements specified in UL 7460, any cracking of a polymeric material that would be exposed to water is considered unacceptable. All other parts constructed of materials that do not comply with the enclosure requirements shall be removed during this test.
c) Abnormal Operations — See Abnormal Operation Tests, Section 45.
d) Mold-Stress Relief Distortion — In addition to the test requirements specified in UL 746C, any cracking of a polymeric material that would be exposed to water is considered unacceptable. All other parts constructed of materials that do not comply with the enclosure requirements shall be removed during this test.
e) Strain Relief — This test is only required if the strain relief means is secured to the enclosure or is an integral part of the polymeric enclosure.
f) UV Resistance — This test is only required if the equipment is intended for outdoor use. All other parts constructed of materials that do not comply with the enclosure requirements shall be removed during this test.
g) Flammability — Minimum flammability rating of polymeric enclosures shall be 5VA, 5VB, V-O, V-i, V-2 for portable appliances and 5VA for all other appliances.
h) Water Exposure and Immersion — Polymeric materials shall comply with UL 746C.
i) Dimensional Stability — Polymeric materials shall comply with UL 7460.
j) Conduit Connections — Products permanently connected electrically shall comply with the requirements in UL 7460.
8.9 The polymeric housing of a component is not considered to be an appliance enclosure unless this part is the sole insulation (excluding air) between a live part and an external surface of the appliance.
8.10 Cast- and sheet-metal portions of the enclosure shall not be thinner than indicated in Table 8.1.
8.11 The enclosure of a remotely or automatically controlled appliance shall reduce the risk of molten metal, burning insulation, flaming particles, or the like from falling on combustible materials, including the surface upon which the appliance is supported.
8.12 The requirement in 8.11 will necessitate that a switch, a relay, a solenoid, or the like be individually and completely enclosed, except for terminals, unless it can be shown that malfunction of the component would not result in a risk of fire, or there are no openings in the bottom of the appliance enclosure. It will also necessitate the use of a barrier of noncombustible material.