Which high side rating is used for transformers specifically designed for delta configurations?

The high side rating for transformers specifically designed for delta configurations is identified by its primary voltage rating, which is crucial for system compatibility and performance. For transformers that operate in a delta configuration, the high side voltage is represented in a manner that indicates the phase-to-phase voltage, which is a requirement for this type of connection.

In the case of the correct answer, the voltage rating "12000-" signifies a 12,000-volt primary winding in a typical three-phase distribution system. Delta configurations usually deal with higher voltage connections, and this rating indicates that the transformer is capable of handling that level of voltage effectively. Delta connections do not have a neutral point, unlike wye configurations, and thus the voltage is expressed per phase (which measures between any two of the three phases), reinforcing why this rating fits.

The other options either reflect lower voltage configurations or do not pertain to three-phase delta systems as needed for this question. For instance, options like "240/120" or "120/240" pertain to lower residential voltages typically seen in single-phase systems rather than the high side values required for transformers in a delta configuration. The "12470GRDY/7200-" option suggests a grounded wye configuration rather than a delta