In a transformer, what does the term "wild leg" refer to?

The term "wild leg" specifically refers to the 208-volt conductor in a three-phase electrical system. This conductor is derived from the way transformers are configured, particularly in delta-wye (Δ-Y) setups. In such systems, the line voltage between any two phases typically results in a 208-volt reading, whereas the phase-to-neutral voltage is 120 volts.

The wild leg can often be identified in a 120/208-volt three-phase system, where one leg (the wild leg) is at a higher potential compared to the others, which typically measure 120 volts. It’s crucial to authenticate the wild leg correctly during installation or troubleshooting, as misidentifying it can lead to potential safety hazards.

The other options do not correctly describe the wild leg; a neutral conductor does not carry voltage as the wild leg does, and the 240-volt leg refers to a different configuration in single-phase systems. Additionally, the ground terminal has a different purpose altogether, serving as a safety feature rather than a conductor for power distribution.