What length of a 60 Hz transmission line is generally considered short?

In the context of electrical transmission lines, a "short" line typically refers to a segment where the electrical characteristics can be treated using simplified models. For AC transmission lines, including those operating at 60 Hz, a line is considered short if its length is small enough that the effects of capacitance and inductance can be ignored in certain calculations, and the line can essentially be modeled as a series impedance.

Generally, transmission lines under about 250 kilometers (approximately 155 miles) can be considered short for the purposes of many analyses. However, within the common conventions used in electrical engineering, a length of less than 50 miles is typically seen as a more practical threshold for categorizing a line as "short." At this length, the line's reactance and resistance can dominate the behavior of the system, allowing for straightforward calculations without complex transmission line theories like the use of the two-port network.

This specific threshold is reinforced by standard practices in power system analysis where lines of lesser lengths can often be simplified effectively, aligning with common operating conditions in electrical power systems. Thus, the chosen response aligns well with established standards in the field.