CONVERGENT SERIES 51 



Length of line 250 Km. = 155.34 miles. 



Spacing , 6 feet. 



Conductor No. ooo copper wire. 



Total resistance of one conductor, 51.5 ohms. 



Total reactance of one conductor, 48.0 ohms. 



Total susceptance of one conductor, 3.724 X lo" 4 mhos. 



Load (at receiver end), 15,000 K.V.A., 86,600 volts, 80% 



P.F., three phase, 25 cycles. (Prob. 5, Chap. V.) 

 Ans. 15,153 K.V.A., 97,934 volts, line; 56,542 volts, star; 



89.71%. 



4. Find, by the convergent series, the per cent voltage drop, the 

 per cent loss, and the power factor at the supply end of the following 

 line: 



Length of line 100 miles. 



Spacing 6 feet. 



Conductor No. oooo copper wire. 



Take r = 0.267, = 0.727, b = 6.03 X io~ 6 . 

 Load (at receiver end), 100 amperes per wire, 60,000 volts, 

 95% P.F., three phase, 60 cycles. [Prob. 4, Chap. V.] 



Ans. 13-03% drop, 7.60% loss, 96.66% P.F. 



5. Find, by the convergent series, 



(a) star voltage at supply end at full load, 



(b) star voltage at supply end at no load, 



(c) regulation volts (star), at the supply end, 



(d) amperes per wire at supply end at full load, 



(e) power factor at supply end at full load, 

 (/) loss in line at full load, 



(g) efficiency of the transmission line, 



(h) amperes per wire at supply end at no load (i.e., the 

 "charging current"), 



(i) power factor at supply end at no load, 



(/) loss in line at no load, for the following line: 



Length of line 300 miles. 



Spacing 10 feet. 



Conductor, No. ooo copper cable of 0.330 ohm per mile. 

 Load (at receiver end), 18,000 K.V.A., 104,000 volts, 90% P.F.,- 

 three phase, 60 cycles. (Prob. 6, Chap. V.) 



