Determine the dc resistance in ohms per km of Bluebell at 20°C by Eq. (4.2) and the information in Prob . 4.1, and check the result against the value listed in tables of 0.0 1 678 Ω. per 1000 ft. Compute the dc resistance in ohms per kilometer at 50°C and compare the result with the ac 60-Hz resistance of 0. 1 024 Ω/mi listed in tables for this conductor at 50°C. Explain any difference in values. Assume that the increase in resistance due to spiraling is 2%.
Prob 4.1
The all-aluminum conductor (AAC) identified by the code word Bluebell is composed of 37 strands, each having a diameter of 0.1672 in. Tab les of characteristics of AACs list an area of 1 ,033,500 emil for this conductor (1 emil = (π/4) X 10-6 in2). Are these values consistent with each other? Find the overall area of the strands in square millimeters.