What is the transformer coil voltage required to connect to a 12470 volt 3-phase 4-wire system?

To connect to a 12,470-volt 3-phase, 4-wire system, the transformer coil voltage required is correctly identified as 7,200 volts. This is because in a typical distribution system, the primary voltage on the transformer is stepped down from the distribution voltage to a lower level for local use.

In a 12,470-volt system, the line-to-ground voltage is 7,200 volts when considering a Wye (Star) connection. Here, one phase to neutral (or ground) voltage is considered, which is half of the line-to-line voltage. Therefore, 12,470 volts can be classified into two phases, making the voltage on each phase approximately 7,200 volts when calculated.

The other options serve different roles in power systems. A voltage of 2,400 volts is typical for secondary distribution; however, it does not apply directly to the specified system. A voltage of 12,470 volts is the line voltage of the overall system but doesn't pertain to the coil voltage needed for the transformer on its own. Lastly, 480 volts is frequently used in industrial applications for equipment but is not relevant in the context of connecting to a higher voltage distribution system like the 12