UL 1332-2016 pdf download – Organic Coatings for Steel Enclosures for Outdoor Use Electrical Equipment.
8.2 Removal of the coating along the scribe shall be conducted by scraping the specimen vigorously with a rigid spatula, knife or similar instrument with no sharp edges or corners. 8.3 The apparatus used for the moist carbon dioxide-sulfur dioxide-air exposure is to consist of a chamber having a volume of at least 3 cubic feet (0.08 m 3 ) with a water jacket and thermostatically controlled heater to maintain a temperature of 95 plus 2 or minus 3°F (35 plus 1 .1 or minus 1 .7°C). 8.4 Sulfur dioxide and carbon dioxide are to be supplied to the test chamber from commercial cylinders containing the gases under pressure. An amount of sulfur dioxide equivalent to 1 percent of volume of the test chamber, and an equal volume of carbon dioxide are to be introduced into the chamber each working day. Prior to introducing the new charge of gas each day, the remaining gas-air mixture from the previous day is to be purged from the chamber. A small amount of water (approximately 1 0 ml/0.0003 m 3 of chamber volume) is to be maintained at the bottom of the chamber for humidity. This water is not to be changed during the exposure. 8.5 The specimens are to be supported in plastic racks at an angle of 1 5 to 30 degrees from the vertical. 9 Light and Water Test for Clear Coatings 9.1 Two scribed and two unscribed specimens shall be exposed for 500 hours to light and water in accordance with 9.3. Following exposure, specimens shall: a) Except for the scribe, show no base metal corrosion, b) Show no blisters, c) Not exhibit an average creepage distance from the scribe greater than rating No. 6 [1 /1 6 to 1 /8 inch (1 .6 – 3.2 mm)] as designated in the Standard Test Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive Environments, ASTM D1 654, Procedure A; with maximum isolated spot not exceeding 3/8 inch (9.5 mm), and d) Not show more than light corrosion of the base metal beneath coating uplifted from the scribe with no visual pitting of substrate and only incipient buildup of corrosion products.