TABLE I 



Formulas for Short Constant-Voltage Lines 

 Conditions Given at Receiver End 



These formulas are exact when the line is short. 

 When the line is 20 miles long, they are correct within 

 approximately l / w of i per cent of line voltage. 



Conditions Given: 



E Voltage at receiver end. 

 E 8 = Voltage at supply end. 

 R = Resistance of one conductor. 

 X = Reactance of one conductor. 



(See Tables VII-XII, "Transmission 



Line Formulas") 

 P = In-phase current of the load, in total 



amperes. 

 cos 9 = Power-factor, lagging, of the load. 



(i) Circle Diagram. 



Describe a circle with centre (a, b) and radius c, where 





Draw a straight line at an angle B below the base 

 line, where cos 6 is the power-factor, lagging, of the 

 load. 



By means of a pair of dividers, add the ordinates of 

 the straight line to those of the circle, thus plotting the 

 ellipse giving the Kva. of synchronous motors required. 



91 



