4.4 Repeat Example 4.2, parts (a) and (b), assuming a three-phase 34.5 kV wye-grounded feeder main that has 350 kcmil 19-strand copper conductors with an equivalent spacing of 37 in between phase conductors and a lagging-load power factor of 0.9. 4.5 Repeat part (a) of Problem 4.4, assuming 300 kemil ACSR conductors. 4.6 Repeat Problem 4.5, assuming a lagging-load power factor of 0.7. 4.7 Repeat Problem 4.6, assuming AWG #4/0 conductors. Example 4.2 Assume that a three-phase 4.16 kV wye-grounded feeder main has #4 copper conductors with an equivalent spacing of 37 in. between phase conductors and a lagging-load power factor of 0.9. a. Determine the K constant of the main by employing Equation 4.77. b. Determine the K constant of the main by using the precalculated percent voltage drop per kilovolt-ampere-mile curves and compare it with the one found in part (a). Solution a. From Equation 4.77, K - cos0 + x sine)((1/3)x1000) V,VB where r = 1.503 9/mi from Table A.1 for 50C and 60 Hz *1 = X, + Xy = 0.7456 0/mi x, = 0.609 0/mi from Table A.1 for 60 Hz x/ = 0.1366 0/mi from Table A.10 for 60 Hz and 37 -in. spacing cos 0 = 0.9, lagging V, = VB = 2400 V, line-to-neutral voltage Therefore, the per unit voltage drop per kilovolt-ampere-mile is (1.503 x0.9+0.7456x0.4359)((1/3) x1000) 2400 = 0.0001 VD,,/(kVA.mi) or K = 0.01%VD/(kVA .mi) b. From Figure 4.26, the K constant for #4 copper conductors is K = 0.01%VD/(kVA.mi) which is the same as the one found in part (a)