Document j5oXeb9k9Eq6y8EdjM8XGgoN

SEPTEMBER 24, 1991 THERMOPLASTIC-INSULATED WIRES AND CABLES -- UL 83 19 Conductor Size 14 --7 AWG 6--2 1 --4/0 TABLE 15.6 * THICKNESSES OF INSULATION ON TYPE TA WIRE Minimum Acceptable Thicknesses PVC Insulation Asbestos Insulation Average At Any Point Average At Any Point Mils mm Mils mm Mils mm Mils mm 20 0.51 18 0.46 20 0.51 16 0.46 30 0.76 27 0.69 25 0.64 21 0.53 40 1.02 36 0.91 30 0.76 26 0.66 16. Centering 16.1 Within the limits specified in paragraph 15.1, the insulation shall have a circular cross section, shall be applied concentrically about the conductor (so that the conductor is well centered in the insulation), and shall fit tightly thereto. If the insulation is applied in more than one layer, adjacent layers shall form an integral mass. This mass shall be taken as a whole for all measure ments and tests. NONMETALLIC COVERINGS AND FILLERS 17. Braids in General 17.1 A Type TA wire and a Type TBS wire shall have an impregnated overall braid applied to the outer surface of the insulation. The braid shall be one of the following: entirely of cotton, entirely of spun rayon, entirely of glass, a combi nation of 50 percent glass and 50 percent spun rayon, or a combination of 50 percent glass and 50 percent cotton (see rupture test in paragraph 27.2). Type FEPB wire in size Nos. 14 -- 7 AWG shall be provided with a lacquer-coated glass braid applied over the insulation. Type FEPB wire in size Nos. 6 -- 2 AWG shall be provided with either of the following: A. An impregnated overall close-weave braid of a good-quality long-fiber chrysotileasbestos yarn having a magnetic rating (MR) not higher than 4 and having an 80 percent or higher asbestos content by weight after ex traction of the impregnating compound. B. A lacquered overall close-weave braid consisting of 50 percent of glass and 50 per cent of the asbestos yarn mentioned in item A. Type FEP and Type TFE wires shall not be provided with any overall covering. 18. Fillers 18.1 Fillers are acceptable in a pump cable or in a multiple-conductor assemble but are . not required. 19. Cotton Braids 19.1 A cotton braid shall be of a close-weave, shall completely cover the insulation over which it is applied, and shall be fabricated on a machine having the same number of ends per carrier throughout. Each end shall consist of the same kind (that is, soft or glazed), size, and ply of yarn. 20. Glass Braids 20.1 A glass braid and a combination glassand-cotton or glass-and-spun-rayon braid shall comply with the requirement in paragraph 19.1, and shall employ a glass yarn not smaller than No. 150--1/0. 0050 SC-ELEC-10075