Omicron Lab CT Analyzer, User Manual

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Setup and Connection
Figure 2-12 Bushing-type CT outside the delta winding power transformer
CTs inside the delta winding
For CTs that are integrated in the delta winding of the transformer, it is not
possible to read the CT ratio directly since the delta winding acts as a voltage
divider. In order to obtain the correct CT ratio, the ratio value determined by the
CT Analyzer has to be corrected.
For this purpose, the CT Analyzer provides a "Delta Compensation" field on the
CT- Object card where you can select the delta compensation factor depending
on the bushing terminals that are used for primary signal measurement.
Figure 2-13 Setting the delta compensation on the CT-Object card