Which factor is NOT relevant when determining the type of connection on the high side of a transformer?

When determining the type of connection on the high side of a transformer, environmental conditions are not a relevant factor. The design and configuration of transformer connections primarily depend on the electrical characteristics of the system, such as the transformer rating, system voltage, and the intended connection type.

The transformer rating is crucial because it indicates the maximum load the transformer can handle, which helps specify the connection type to manage the voltage and current levels effectively. Similarly, system voltage is fundamental to ensure that the transformer operates within its designed voltage levels for safety and reliability. The connection type chosen must align with the voltage requirements and the rating of both the transformer and the overall system.

In contrast, environmental conditions, such as temperature or weather extremes, while important for overall installation considerations and long-term performance, do not dictate the specific electrical connection type on the high side of the transformer. Therefore, they are deemed irrelevant in that specific context.