UL 6:2007 pdf download – Electrical Rigid Metal Conduit一Steel.
6.22.6 A record shall be made when the immersed part of the specimen has any deposit of bright, firmly adhering copper, exclusive of any threaded area, and the 13 mm (1/2 in) cut-end portions and any 3 mm (1/8 in) longitudinal cut-edge portions. When bright adhering copper is not found, the process of immersing. washing, rubbing, drying, examining, and recording shall be repeated up to the required number of immersions, or until the presence of copper is noted, whichever comes first, using the same specimen and beaker of solution. After the dips are completed on any one specimen. the portion of the solution of copper sulfate used shall be discarded, A fresh portion of the solution shall be employed for each of any succeeding specimens. A protective zinc coating that provides the sole means of primary corrosion resistance on the exterior of the conduit shall be such that a specimen of the finished conduit does not show a bright. adherent deposit of copper after four 60-s imrnersions in a copper sulfate solution. A protective zinc coating that provides the sole means of pnmary corrosion resistance on the interior of the conduit shall be such that a specimen of the finished conduit does not show a bright, adherent deposit of copper after one 60-s immersion In a copper sulfate solution. When it is desired to show the character of the bright metallic copper deposit on an exposed steel surface, prepare a reference standard for comparison as follows. Partially submerge a zinc-coated specimen in strong hydrochloric acid until violent action ceases. Immediately remove the specimen, wash, and wipe it dry. Then dip the specimen, with an area of bare surface Thus exposed. induding a portion with zinc coating intact, for a few seconds in the copper sulfate solution at a temperature 0(16 — 20°C (61
— 66°F), remove It, wash it, and wipe It dry. Prepare this copper-coated reference standard at the time of testing. For an alternate test method to the one described in Clauses 6,2.2.1 — for determining compliance with the evaluation of zinc coating requirements, see Reference Item No. 8. Annex A.
6.2.3 Organic coating Elasticity test The organic coating used to protect the interior of the conduit, when applied to a sheet-steel test piece and baked in an oven for 5 h. shall withstand without damage 10 successive bends of the test piece back and forth through an angle of 180 degrees against an edge having a radius of 1.6 mm (1/16 In). The apparatus shall consist of flat test pieces of sheet steel 75 by 125 mm (3 by 5 in) long arid approximately 0.25 mm (0.010 in) thick, an oven for baking the test pieces, and a vise with jaws at least 75 mm (3 in) wide for holding the test pieces during the bending test. The 75-mm (3in) edge of each jaw shall be rounded to a radius of 1.6 mm (1/16 in). Two test pieces shall be cleaned with a suitable organic solvent to remove any grease and foreign material and shall then be dipped in the organic coating. After air drying for 30 mm, the test pieces shall be suspended by means of short wires in the oven. Samples shall be baked for 5 h at the normal baking temperature for the organic In question but, If the normal baking temperature is lower Than 135°C (275°F) or the enamel is regularly air dried, the oven temperature shall be maintained at 135 — 150°C (275 — 302°F). Air oven conditioning exposure Six scribed and six unscribed specimens of each coating shall be conditioned for 240h at a temperature of 100 +2°C (212 +4°F) in an air-circulating oven. Conduit that is marked with a temperature rating above 90*C (200^F) shall be conditioned at the rated temperature plus 10*C (18*F), for which the rated temperature shall be any temperature in excess of 90*C (200F) at 25°C (45°F) increments. These specimens shall be used for the resistance to salt spray (fog) (Clause and the resistance to moist carbon dioxide-sulfur dioxide-air (Clause tests.