The 120/208/240 V secondary system can be derived from a three-phase connection of transformers with a split 120/240 V secondary winding connection. In addition, which of the following is correct?
1) the transformers must be connected as Y-Y and all the secondary winding mid-points must be grounded.
2) the transformers must be connected either as Y-D or D-D and only one of the secondary mid-points is grounded.
3) The transformers must be connected as Y-Y with one of the secondary mid-points grounded.
1) the transformers must be connected as Y-Y and all the secondary winding mid-points must be grounded.
2) the transformers must be connected either as Y-D or D-D and only one of the secondary mid-points is grounded.
3) The transformers must be connected as Y-Y with one of the secondary mid-points grounded.
