When running 120V between two buildings, how many ungrounded conductors must be taken from the first structure?

When running a 120V circuit between two buildings, only one ungrounded conductor is required from the first structure. In standard residential electrical systems in the United States, a 120V circuit typically consists of one ungrounded (hot) conductor and a neutral conductor.

The ungrounded conductor carries the current to the load, while the neutral conductor provides a return path for the current. Since the question specifies running 120V, this is the configuration that aligns with how standard 120V circuits are designed. Additional conductors, such as a ground wire, may be required for safety purposes, but they do not count as ungrounded conductors since they serve a different function.

This understanding of how electrical systems are configured is crucial for proper installation and safety compliance in electrical work, particularly when connecting separate structures.