11
3.4
Transformer Connections
In order to monitor generator output voltages greater than 600 Volts, external potential transformers must be used.
Gen Freq (0066h) VL-L AVG (0064h) VA-B (006Ch) VB-C (006Dh) VC-A (006Eh) VL-N AVG (0094h) VA (0072h) VB (0073h) VC (0074h) IAVG (0065h) IA (006Fh) IB (0070h) IC (0071h)
Star OK OK OK OK OK OK OK OK OK OK OK OK OK
3-Wire Delta OK OK OK OK OK Invalid Invalid Invalid Invalid OK OK OK OK
4-Wire Delta OK OK OK OK OK OK OK OK OK OK OK OK OK
2-Wire 1-Phase OK OK OK Invalid Invalid Invalid Invalid Invalid Invalid OK OK OK Invalid
3-Wire 1-Phase OK OK OK Invalid Invalid OK OK OK Invalid OK OK OK Invalid
Note: The EMCP 3 must be programmed for the correct winding ratios when connecting external potential transformers. See “Setpoint Programming” for more information on how to program the winding ratios. Note: The wye configuration of external potential transformers is preferred for 4-wire wye generators because of the greater accuracy when loads are unbalanced. With the open delta configuration, some power parameters can not be determined. These parameters are real power phase A, B, C and power factor phase A, B, C. For maximum accuracy, the open delta configuration of external potential transformers should be used only for 3-wire delta generators.
