112 TRANSMISSION LINE FORMULAS 



TABLE IV. K FORMULAS FOR TRANSMISSION LINES. 

 CONDITIONS GIVEN AT SUPPLY END. 



Accurate within approximately T V of i% of line voltage up to 100 miles 

 and 2 of i% up to 200 miles, for lines with regulation up to 20%. 



K = 6 ^ CycleS ^. K = 2.16 for 60 cycles. K = 0.375 for 25 cycles. 

 10,000 



Conditions given: 



K.V.A. = K.V.A. at supply end. 



E s = Full load voltage at supply end. 

 cos 6 = Power factor at supply end. 

 K.W. = K.V.A. cos 0. 



r = Resistance of conductor per mile. (From Tables VII-VIII.) 

 x = Reactance of conductor per mile. (From Tables IX-XII.) 

 I = Length of transmission line in miles. 



Then P a = IoooK -V.A. cos0 = In _ phase current at supply end (in 



total amps.), 

 eactive currer 

 total amps.), when current is lagging. 



Q s = IoooK -J- A - sing = Reactive current at supply end (in 



1000 K.V.A. sin 6 , . . , ,. 

 = when current is leading. 



