AC GENERATOR OPERATIONAC GeneratorsACGeneratorConnectionsFigure 8 Delta ConnectionAs shown in Figure 7, there are six leads from thearmature of a three-phase generator, and the output isconnected to an external load. In actual practice, thewindings are connected together, and only three leads arebrought out and connected to the external load.Two means are available to connect the three armaturewindings. In one type of connection, the windings areconnected in series, or delta-connected (D) (Figure 8).In a delta-connected generator, the voltage between anytwo of the phases, called line voltage, is the same as thevoltage generated in any one phase. As shown in Figure 9, the three phase voltages are equal,as are the three line voltages. The current in any line is times the phase current. You can3see that a delta-connected generator provides an increase in current, but no increase in voltage.An advantage of the delta-connected AC generator is that if one phase becomes damaged orFigure 9 Characteristics of a Delta-Connected Generatoropen, the remaining two phases can still deliver three-phase power. The capacity of the generatoris reduced to 57.7% of what it was with all three phases in operation.ES-10 Page 12 Rev. 0