For an aluminum service cable on a 3-ton air conditioner, how does its diameter compare to that of copper?

When considering the relationship between the diameter of aluminum service cable and that of copper for a 3-ton air conditioner, it is essential to understand the conductivity and physical properties of both materials. Aluminum has a lower electrical conductivity compared to copper. Consequently, to achieve the same electrical current-carrying capacity, the diameter of the aluminum wire needs to be larger than that of copper. This compensates for the lower conductivity of aluminum, ensuring that it can handle the necessary electrical load without overheating or causing inefficiency.

In practical terms, if you were using aluminum wire, you’d choose a larger gauge to match the performance of a smaller gauge copper wire in terms of the same application. This is why, in the context of this question, the diameter of the aluminum service cable is considered larger than that of the copper cable for the same electrical capacity. Thus, the correct answer reflects this understanding of the comparative sizing needed to maintain electrical safety and efficiency in HVAC applications.