NEC Commercial Electrical Practice Test

What distinguishes the voltage differences in conductors connected in a delta configuration?

1. The outer finish color

2. The wire gauge

3. The insulation type

4. The number of conductors

The correct answer is: The outer finish color

In a delta configuration, the voltage differences in conductors are primarily related to the electrical connections and the arrangement itself, rather than physical attributes like color, gauge, insulation type, or the sheer number of conductors. In a delta system, three conductors are connected in a closed loop (or triangle), and each conductor is connected to a phase of the power source. The distinguishing characteristic of the voltage differences in a delta configuration arises from the phase relationship between the conductors, where each conductor carries a phase of the electrical supply. This configuration enables each pair of conductors to have a voltage difference equal to the line voltage, while the phase-to-neutral voltage (if considered) is actually lower. The generators or transformers providing power have their outputs connected in a way that the resultant system allows for a balanced load across the three phases, thus creating specific voltage differences based on the phase arrangement. The other factors mentioned—like the outer finish color, wire gauge, insulation type, and the number of conductors—do not inherently affect the voltage differences observed in the delta connection. Voltage characteristics are strictly determined by the electrical relationships and the configuration itself instead of the physical or material qualities of the conductors involved.