In a three-phase system, how many conductors are typically used?

In a three-phase system, the typical configuration involves three conductors for the three phases of the system, which carry the alternating currents. Additionally, a neutral conductor is often included to balance the phases and provide a return path for imbalance in the load. This configuration allows for the efficient distribution of power and is commonly used in both industrial and commercial applications.

The inclusion of a neutral conductor is particularly important in systems where single-phase loads may be connected, ensuring that any unbalanced load can still be effectively managed. This setup facilitates the safe operation of electrical equipment and minimizes the risk of over-voltages that can occur due to unbalanced loading.

The other options do not accurately reflect the standard configuration for a three-phase system. For example, using only two conductors plus a ground would not adequately provide the three-phase power necessary for most applications, while using only one conductor would not provide the phase separation needed for three-phase operation. Thus, the correct and most common answer is indeed three conductors plus a neutral.