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Table 50.2
Gasket conditioning
Table 50.2 revised July 8, 1996
Maximum gasket temperature
a
Conditioning
°C (°F) Rubber or neoprene Thermoplastic
60 (140) Air oven aging for 70 hours at 100 ±2°C
(212 ±3.6°F)
Air oven aging for 168 hours at 87 ±2°C
(189 ±3.6°F)
75 (167) Air oven aging for 168 hours at 100 ±2°C
(212 ±3.6°F)
Air oven aging for 240 hours at 100 ±2°C
(212 ±3.6°F)
80 (176) Air oven aging for 168 hours at 113 ±2°C
(235 ±3.6°F)
90 (194) Air oven aging for 240 hours at 121 ±2°C
(250 ±3.6°F)
Air oven aging for 168 hours at 121 ±2°C
(250 ±3.6°F) or 1440 hours at 97 ±2°C
(207 ±3.6°F)
105 (221) Air oven aging for 168 hours at 136 ±2°C
(277 ±3.6°F)
a
Measured during the normal temperature test.
51 Atomized Water Test
Section 51 effective April 13, 1993
51.1 The enclosure specified in Section 7, Enclosures Used for Protected Environment, is to be subjected
to a spray of atomized water by using a nozzle that produces a round pattern 3–4 inches (75–100 mm)
in diameter, measured 12 inches (305 mm) from the nozzle. The pressure is to be 30 psi (207 kPa). The
water is to be supplied by a suction feed with a siphon height of 4–8 inches (100–250 mm). No less than
5 fluid ounces per linear foot (495 cc/m) of test length is to be applied at a rate of 3 gallons (11.4 L) per
hour. The nozzle is to be held 12–15 inches (305–380 mm) from the enclosure, and the spray of water is
to be directed at all areas of potential dust entry, such as seams, joints, bushings, connectors, and the
like. A conduit may be installed to equalize the internal and external pressures, but it is not to serve as a
drain. No sealing compound is to be used.
51.2 For this test, covers, except covers that are part of the protected environment enclosure, are to be
removed.
51.3 At the conclusion of the procedure specified in 51.1, the product is to be subjected to the dielectric
voltage withstand test specified in 39.1(a), and, if cord connected, to the Leakage Current Test in Section
32.
OCTOBER 15, 2004UL 45870
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