296 



ELECTRICAL EQUIPMENT 



spaced 120 apart as in Fig. 164. Such a method is, however, 

 rarely used because the e.m.f.'s of the sections, which are com- 

 bined with each other to form one-phase of the three-phase cir- 

 cuit, are out of phase with each other, and the resultant e.m.f. 



FIG. 164. 



FIG. 165. 



21 



ooooooooooooo 



FIG. 166. 



FIG. 168. 



FIG. 167. 



and, consequently, the capacity of the machine is reduced, simply 

 because the most effective use of the windings is not obtained. 

 The highest output is, however, obtained with the delta and star 

 connections where groups of similar phase relations are connected 

 in series or parallel as in Figs. 165 to 168. Of these, however, the 



