Under what condition would a transformer rated at 120/240 or 240/480 have internal connections?

In the context of transformer ratings, understanding the significance of KVA ratings and how they affect internal connections is crucial. A transformer rated at 120/240 or 240/480 with an internal connection typically indicates that it can provide a dual voltage capability while maintaining efficiency and safety within certain loading parameters.

Transformers rated under 167 KVA are often designed with internal connections that allow them to switch between different voltage configurations easily. This is useful in various applications, particularly in residential or light commercial installations, where the load demand does not exceed specific levels. The internal connections enable the transformer to handle voltage variation and balance loads effectively.

When transformers are rated above certain levels, particularly over 167 KVA, they tend to be designed differently. They may require external configurations or different types of connections to cater to the higher load demands and efficiency requirements of larger systems. These larger transformers are generally used in industrial settings where the demand can fluctuate significantly.

Thus, the condition stating that a transformer rated under 167 KVA would have these internal connections is accurate, as it aligns with standard practices in transformer design for efficiency, safety, and functionality in typical usage scenarios.