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ELECTRICAL EQUIPMENT 



one alternator tend to increase above that of any of the others, 

 a circulating current would flow between this alternator and 

 the ones having the lower voltage. This exchange current, of 

 course, would be out of phase with the voltage and, therefore, 

 would swing the current in the current coil of the A.C. magnet 

 in phase with that of potential current of this magnet. This 

 would cause the regulator on this unit to reduce the generator 

 voltage, which would, of course, eliminate the possibility of any 

 cross currents between the different alternators operating upon 

 the bus-bars. Of course, if the voltage on one machine tended to 



Bus Bars 



FIG. 220. Individual T.A. Regulator Operation with Exciters not in Parallel. 

 Main Generators Operating in Parallel. 



drop, the regulator would operate in the opposite direction, causing 

 the voltage on this generator to rise, which would also eliminate 

 the above-mentioned cross currents. 



Very complete instruction for the connection and operation of 

 the different forms of T.A. regulators can be obtained from the 

 manufacturer. 



Line Drop Compensation. Compensation for line drop may 

 also be obtained with these regulators. For ordinary installations 

 the compensating winding on the alternating current control 

 magnet is connected to a current transformer in the main feeder. 



