THE POLYPHASE SYSTEM. 



109 



2. Referring to the receiving circuits, (a) Electromotive force 

 relations. Given the electromotive forces E v E 2 and E 3 between 

 the mains as shown in the clock diagram Fig. 103, then the elec- 

 tromotive forces acting on the respective Y-connected receiving 

 circuits are represented by the lines A, B and C. Therefore the 

 value of the electromotive force acting on each Y-connected receiving 

 circuit is equal to the electromotive force betzveen mains divided 

 by 1/3. 



(ft) Current relations. In the Y-scheme of connection the 

 current in each main is identical with the current m each receiv- 

 ing circuit. 



56. Electromotive force and current relations in the A-scheme of 

 connections. 



(i) Referring to the generator, (a) Electromotive force rela- 

 tions. In the A-scheme of connections the electromotive forces 



Fig. 104. 



between mains are identical with the electromotive forces devel- 

 oped by the respective armature windings. 



Current relations. Let 7 ; 



7 2 and 



L be the currents in 



mains I, 2 and 3 respectively, each being considered positive 



