SWITCHING EQUIPMENT 



519 



condition will result in the isolation of that line without affecting 

 any other. 



In the diagram (Fig. 325), the solid arrows indicate the rela- 

 tive directions and intensities of the energies in the various parts 

 of such parallel lines when in normal operation and with power 



FIG. 324. Connections for Polyphase Induction-type Reverse-power Relay 

 for Grounded Three-phase Circuits. 



being fed from Station A to Station B. Should power be reversed 

 and fed from B to A, then all solid arrows would be inverted. In 

 either case it will be noted that the current coils of all relays oppose 

 each other. There will be no tendency to operate under these 

 conditions no matter how much current may be carried by the tie 

 line. 



