UL 1640:2000 pdf download – Portable Power- Distribution Equipment
UL 1640:2000 pdf download – Portable Power- Distribution Equipment.
22.3 Wilt, reference to 22.2, to determine whether water has entered the interior of a wiring device, It may be required to provide one or more passages in that portion of the wiring device enclosed by the equipment so that any water entering the wiring device is capable of being drained from the wiring device. During the required tests, these passages are to be blocked with puny or the like; and, after the tests. the putty is to be removed and any water that has entered is to be drained from the wiring device.
22.3 eI.c*r. Ma,ch 1,2001
23 Icing Test
23.1 An enclosure marked Type 3R shall not be damaged after the ice has melted at tile conclusion of the test specified In 23.2. An enclosure that has no external cavities that trap water Is considered to comply with 23.2 without being tested.
23.2 The enclosure is to be mounted in a room that can be cooled to 20°F (minus 6.7°C). A metal test bar, 1 inch (25.4 mm) in diameter and 2 feet (610 mm) long, is to be mounted in a horizontal position in a location where it will receive the same water spray as the enclosure being tested. Provisions are to be made for spraying the entire enclosure from above with water at an angle of approximately 45 degrees from the vertical. The water temperature is to be 32 — 37°F (0 — 2.8°C). Spraying facilities that provide 1
— 2 gallons (3.8 — 7.6L) per hour per square foot (928 cm2) of area to be sprayed are acceptable. The room temperature is to be lowered to 35°F (1.7°C). The spray of water is to be started and continued for at least 1 hour, maintaining the room temperature at 33 — 37°F (0.56 — 2.8°C). The room temperature is then to be lowered to 20 — 27°F (minus 6.7 — minus 2.8°C) while continuing the water spray. The rate of change in room temperature Is not critical and is to be whatever is obtainable with the cooling method used. The water spray is to be controlled to cause ice to build up on the bar at a rate of approximately 114 inch (6.4 mm) per hour and is to be continued until 3/4 inch (19 mm) of ice has formed on the top surface of the bar. The spray is then to be discontinued, but the room temperature is to be maintained at 20 — 27°F (minus 6.7 — minus 2.8°C) for 3 hours so that all parts of the enclosure and the Ice coating have reached the same temperature.
24 Gasket Tests
24.1 A gasket of an elastorneric or thermoplastic material or a composition gasket utilizing an elastorneric material used to comply with the requirements for equipment marked “Suitable for Use In Damp Locations” or one with a Type 3R enclosure is to be subjected to the tests specified in 24.2 — 24.4.
24.2 The requirements in this section apply to a gasket that is required for an electrical enclosure to maintain a tight fit or to comply with the enclosure performance requirements.
24.3 A gasket shall be secured with adhesive or by mechanical means. The gasket and its securing means shall not be damaged when the joint is opened.
24.4 Gaskets shall be of such quality that samples subjected to a temperature 0169—70°C (156 — 158°F) in circulating air for 168 hours have a tensile strength of not less than 75 percent and an elongation of not less than 60 percent of values determined for unaged samples. At the conclusion of the tests, there shall be no visible deterioration, deformation, melting, or cracking ol the material and the material shall not harden as determined by normal hand flexing.
24A Spring-Closing Cycling Test
24A.1 When subjected to the cycling test described in 24A.2, a cover plate shall not crack, deform, or otherwise be damaged so as to allow the entrance of water as verified by the appropriate environmental test outhned in Enclosure Performance, Section 8. Verification of cover plate performance is to be conducted with the cover opened completely and then allowed to assume its natural position.