UL 60950-22-2017 pdf free download

UL 60950-22-2017 pdf free download.Information Technology Equipment – Safety – Part 22 : Equipment to be Installed Outdoors.
used, are applicable to gaskets employed on an ENCLOSURE subjected to water or dust. The additional test of Clause D.4 is applicable to gaskets employed on an ct.osu subjected to oil or coolant. A set of three specimens of the gasket material shall be subjected to the relevant tests.
D.2 Tensile strength and elongation tests
This test is applicable to gaskets, which can stretch (such as 0-rings). Gasket material shall be of such quality that samples subjected to a temperature of 69 C to 70 0C in circulating air for 168 h have a tensile strength of not less than 75 % and an elongation of not less than 60 % of values determined for unaged samples At the conclusion of the tests, there shall be no visible deterioration, deformation, melting, or cracking of the material and the material shall not harden as determined by normal hand flexing.
D.3 Compression test
This test is applicable to gaskets with closed cell construction. The set of specimens of gasket material shall be tested to the requirements of a), b) and C) (see Figure 0.1). On completion of each test, the specimens shall not show signs of deterioration or cracks that can be seen with normal or corrected vision.
a) A cylindrical weight sufficient to apply 69 kPa shall be placed on the middle portion of each specimen for a period of 2 h. At the end of that time the weight shall be removed and the specimen allowed to rest at a room temperature of 25 °C ± 3 °C for 30 mm. The thickness of the gasket shall then be determined and compared with a measurement obtained before the application of the weight. The compression set shall not exceed 50 % of the initial thickness of the specimen.
b) Following the lest specified in a), the same specimens shall be suspended in an air oven at a temperature of 70° C for a period of 5 days. The specimens shall then be tested for compliance with a), approximately 24 h after removal from the oven.
C) Following the test specified in b), the same specimens shall be cooled to the minimum temperature specified by the manufacturer or —33 °C if no minimum ambient temperature is specified for a period of 24 h and then subjected to an impact from a hammer of 1,35 kg mass falling from a height of 150 mm upon removal from the cold chamber. The hammer head shall be steel, 28,6 mm in diameter and have a flat striking surface, 25,4 mm in diameter with slightly rounded edges. The specimens being tested shall be placed on short lengths of 50 mm by 100 mm minimum wooden pieces (clear spruce) when being impacted. Following the impact the specimens shall be examined for evidence of cracking or other adverse effects. The test shall be continued and the specimens impacted every 24 h for two more days. The specimens shall then be removed from the cold chamber, allowed to rest at a room temperature of 25 “C ± 3 “C for approximately 24 h, and then again tested for compliance with a).UL 60950-22-2017 pdf free download.