Which of the following high side ratings is used for a multi-winding transformer?

The high side rating for a multi-winding transformer typically indicates the voltage levels associated with the primary side of the transformer that can handle various configurations and load demands. In this case, the correct choice is one that specifies multiple windings and ground referencing.

The correct answer highlights the specific voltage levels of 12,470 volts grounded (GRDY) and 7,200 volts for the high side, each necessary for accommodating different load scenarios. This specification not only shows the typical voltages in a multi-winding configuration but also addresses safety features through grounding, which is crucial for the protection of equipment and personnel.

The other choices presented do not convey the necessary details regarding multiple high-side configurations or grounding. For instance, single-phase residential ratings like 240/120 and 120/240 provide information on lower voltages used primarily in residential applications, which are not appropriate for describing multi-winding transformers. Likewise, a high-side rating of just 12,000 lacks the detail of a second winding and grounding that is essential for multifaceted energy distribution systems. Thus, the correct answer illustrates the complexity involved in the operation of multi-winding transformers and their grounding considerations.