UL 1063-2017 pdf download – Machine-Tool Wires and Cables.
6.6 Area 6.6.1 Where measured as the means of size verification (see 6.2.2) the cross-sectional area of a conductor shall not be smaller than the minimum indicated for the size in Table 6.2. 6.6.2 The cross-sectional area of a conductor having round strands is to be determined either: a) As the sum of the areas of its component round strands (see 6.6.3), or b) By the weight method outlined in 6.6.4 – 6.6.7. The cross-sectional area of a round compressed-stranded conductor is to be determined by the weight method outlined in 6.6.4 – 6.6.7. 6.6.3 The diameter of a round strand is to be measured over any tin or other metal coating by means of a machinist’s micrometer caliper having flat surfaces on the anvil and on the end of the spindle. The caliper is to be calibrated to read directly to at least 0.001 inch or 0.01 mm with each division of a width that facilitates estimation of each measurement to 0.0001 inch or 0.001 mm. 6.6.4 For determining the cross-sectional area of a conductor by the weight method, the test specimen is to consist of a straight length of a single conductor cut from a sample of the finished wire or cable. The specimen is to be at any convenient room temperature, is to have both of its ends perpendicular to the longitudinal axis of the conductor, and is to have any insulation, separator, and other coverings removed. For an 8 AWG or smaller conductor (8.367 mm 2 or smaller), the specimen is to be at least 48 inches or 1220 mm long. For a conductor larger than 8 AWG (larger than 8.367 mm 2 ), the specimen is to be at least 24 inches or 610 mm long. The length of the specimen is to be measured to the nearest 1/32 inch or 1 mm. The specimen is to be weighed by means of a precision balance to within 0.1 percent of the weight of the specimen. For example, a 4-ft or 1220-mm specimen of an 8 AWG conductor having 19 round strands (Class C) weighs about 0.2 lb or 91 g.
8.2 Average thickness of insulation 8.2.1 The average thickness of the insulation shall not be less than indicated in Table 1 .1 when determined as described in 8.2.2 – 8.2.8. 8.2.2 Measurements from which the average thickness of insulation is to be determined are to be made by means of one of the following instruments: a) A machinist’s micrometer caliper may be used. The caliper is to have flat surfaces on the anvil and on the end of the spindle and is to be calibrated to read directly to at least 0.001 inch or 0.01 mm with each division of a width that facilitates estimation of each measurement to 0.0001 inch or 0.002 mm. b) A dead-weight dial micrometer may be used. The micrometer is to exert a force of 1 0 ±2 gf or 0.10 ±0.02 N on a sample through a flat, rectangular presser foot 0.078 by 0.375 inch or 1.98 by 9.52 mm. The anvil of the instrument is to be of the same dimensions as the presser foot. The instrument is to be calibrated as indicated in (a) of this paragraph.