UL 1839-2016 pdf download – Automotive Battery Booster Cables.
7.1 .3 The insulated conductors of a parallel cord are to be separated. The insulation thickness T 1 of an insulated conductor from a parallel or jacketed cord or from a fixture wire is to be determined as indicated in 7.1 .2 from measurements made at a marked position on a 25 mm (1 in) length of insulated conductor from the finished flexible cord or fixture wire. 7.1 .4 The apparatus for this test is illustrated in Figure 7.1 . The apparatus is to be of brass and is to consist of three rods that are free to move vertically in a support frame. The assembly is to be constructed for use in a heated oven. Each rod is to be straight and 1 9.0 ±0.2 mm (0.75 ±0.01 0 in) in diameter. The weight of each rod is to be 250 g (8.8 oz). The lower end of each rod is to be reduced in diameter to 9.5 ±0.2 mm (0.375 ±0.01 0 in) or for the final 1 9 mm (3/4 in) or length of the rod. The lower end of the reduced-diameter section is to be flat, round, without sharp edges, and both concentric with and perpendicular to the longitudinal axis of the rod. The lower end of the reduced section is to serve as the foot that presses on a specimen during a test. The force on the specimen is to be the sum of the force exerted by the rod (2.45 N or 250 gf) plus that of any weight to be placed on the upper end of the rod to make the total force equal the load specified in Table 7.1 . Each weight is to be indent stamped with its exact weight.
7.1 .5 The frame is to consist of three flat, rectangular plates spaced 57 mm (2-1 /4 in) apart (vertical separation) and parallel to one another in a rigid assembly. The dimensions of the plates are to be the same (plates measuring 21 6 by 70 by 6 mm (8-1 /2 by 2-3/4 by 1 /4 in) are typical). The upper surface of the lower plate is to be the surface against which each rod presses a specimen during a test. That surface is to be horizontal during a test. That surface is to be smooth (the surface is to be refinished when repeated testing indents the surface or makes it rough to the touch). Identically located holes are to be provided through the center and upper plates to serve as guides and supports for the rods, which are to be free to move vertically and not otherwise. The diameter of each hole is to be larger than the 1 9 mm (3/4 in) diameter or diameter portion of a rod for clearance of vertical movement of a rod in the hole. Horizontal separation between the rods is to enable weights to be in place on all three rods at the same time with a clearance between the weights. Each rod is to project a distance above the upper plate that enables a weight to be placed on the upper end of the rod without the weight touching the upper plate while the rod is resting on the lower plate (no specimen under the rod). Means integral with the frame is to keep the frame above the floor of the oven and stable during a test. 7.1 .6 With the applicable weight in place on each rod that is to be used for a test, the apparatus is to be placed beside one or more test specimens in an air oven (a dead air, full draft, or internal fan oven is appropriate) that has been preheated to a temperature of 1 50°C ±1 °C (300°F ±2°F) for specimens from wire or cord with Class 36 TPE insulation or jacket, 1 00°C ±1 °C (21 2 ±2°F) for specimens of Class 30 PE insulation, 1 36°C ±1 °C (277°F ±2°F) for specimens from Type THHN wire, and 1 21 °C ±1 .0°C (249.8°F ±1 .8°F) for all other specimens.