Relative merits of Y and delta connection for alternators

The main advantages obtained with the Y connection are as follows: (1) It is possible to bring out a lead from the neutral point of the winding, which is useful for various purposes. (2) The cost is less than with the delta connection, requiring approximately 58 per cent of the turns. (3) It is not possible for circulating currents of triple frequency to flow in the windings. The delta connection does not appear to have any advantages except as a convenience in design for certain voltages. When used, proper precautions must be exercised in the design to eliminate excessive circulating currents.