UL 1696-2015 pdf download
UL 1696-2015 pdf download.Mechanical Protection Tubing (MPT) and Fittings.
6.11 Heat aging
6.111 Two specimens of the largest size in a range of nonmetallic MPT or composite MPT tubing approximately 610 mm (24 in) in length shall be placed in a full -draft, circulating-air oven at a temperature indicated in Table 3 for 16.8 h. The tubing shall then be removed from the oven and allowed to cool to room temperature for no more than 4 h. After cooling, there shall be no cracks or other visible signs of deterioration on the tubing as a result of the exposure.
6.11.2 A polymeric material that has been previously investigated and determined to have a relative thermal index (RTI.Strength) at or above the manufacturers declared working temperature in accordance with Clause 4.6 at the minimum thickness of the nonmetallic MPT or polymeric layer of composite MPT, need not be subjected to the requirement in Clause 6.11,1. RTI shall be determined by UL 746B or CSA C22.2 No. 0.17.
6,11.3 The apparatus for the air oven aging of specimens shall be as indicated for a Type II oven in ASTM 0 5423, and shall circulate the air within the aging chamber at high velocity. A portion of the air may be recirculated, but a substantial amount of fresh air shall be admitted continuously to maintain an essentially normal oxygen content in the air surrounding the specimens. The exhaust ports of the oven shall be adjusted to achieve 100 to 200 complete fresh-air changes per hour. The blower or other means for circulating the air shall be located entirely outside the aging chamber. The oven shall maintain the specified temperature within 2.0CC (3.6F).
6.12 LiquId tightness
6.12.1 Three samples each of the smallest, intermediate and largest sizes of fittings in a range, having the same material and construction type and intended for use in wet locations, shall be assembled in the intended manner to an approximate 500-mm (20-In) length of MPT, intended for use with the fitting, of the same type and to an appropriate enclosure. When subjected for 30 mm. to the oil spray test described in Clause 6.12.5, there shall be no entrance of oil at either the interlace of the tubing or enclosure. This test is not required for fitlings intended for use only in dry locations and marked in accordance with Clause
7.2.
6.12.2 A fitting intended for mounting either In a threaded opening or a knockout of an enclosure shall be tested in the appropriate size knockout. The results of the test represent installation in a threaded opening. A fitting only intended for mounting in a threaded opening or only in a knockout shall be tested when mounted as instructed by the manufacturer and shall be marked according to Clause 7.2.2. Unless otherwise specified in the manufacturer’s instructions, a locknut provided with a fitting shall be assembled hand-tight plus one-quarter turn
6.12.3 Each distinct type of tubing constwcted of the same material for which the fittings are intended to be used shall be tested.
6,12.4 Any one color in the range of MPT and fittings of the same matenal and construction type is permitted to represent others in the range for the purpose of this test.
6.12.5 Where fittings in a range include both straight and angled designs provided with the same means of securement to the MPT and to the enclosure, only the straight fitting design shall be tested. The results shall be considered representative of the entire range.
6.12.6 The assembled fitting. enclosure and MPT shall be set up at an angle of 45° from the vertical so that a stationary nozzle with a 9.5-mm (3)8-in) diameter opening is located 250 mm (10 in) above the MPT and directed to spray oil vertically downward so as to strike the MPT approximately 25 mm (1 Wi) above the fitting. The mixture shall consist of one part of watersoluble oN with a viscosity of 0.3 and ten parts of waler, and the mixture shall be sprayed through the nozzle at a rate of 7.6 1/mm (2 gal/mm).
6.13 Electrical resistance test
6.13.1 Three samples each of the smallest, intermediate and largest size fitting and MPT shall be assembled as intended in accordance with the manufacturers instructions if provided.
