32 TRANSMISSION LINE FORMULAS 



TABLE IV. K FORMULAS FOR TRANSMISSION LINES. 

 CONDITIONS GIVEN AT SUPPLY END. 



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

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



K = . K = 2.16 for 60 cycles. K = 0.375 for 25 cycles. 



Conditions given: 



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



E 8 = Full load voltage at supply end. 

 cos 6 = Power factor at supply end. 

 K.W. = K.V.A. cos 9. 



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

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

 / = Length of transmission line in miles. 



1000 K.V.A. cos 



Then P a = - = - = In-phase current at supply end (in 



&s 



total amps.). 

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



Qe p = Reactive current at supply end (m 







total amps.), when current is lagging 



looo K.V.A. sin 

 = ^ , when current is leading. 



