What are the voltage values to ground for a secondary rating of 120/240 3-phase 4-wire?

For a secondary rating of 120/240 volts in a 3-phase 4-wire system, the ground voltage to each individual phase is crucial to understanding the system configuration. In this case, the voltage values to ground are derived from the way the phases are connected.

In a 120/240 volt system, one phase is typically set as the reference point at zero volts (ground). The other phases (Phase A and Phase B) will then have voltages of 120 volts to ground and 240 volts between the two phases (120 volts + 120 volts). In a typical 3-phase setup, you have three phases, but for this particular configuration, we reference the ground to show how each phase relates to it.

The correct values of 120, 120, and 208 volts represent the line-to-line voltage when considering the configuration of the three-phase system. The 120 volts is the phase voltage (the voltage from each phase to neutral), while the 208 volts is indicative of the line-to-line voltage which is commonly realized in a three-phase system when you have such combinations.

This understanding of phase ground reference is crucial for various calculations and for ensuring proper connections and safety in electrical systems. Thus, option B accurately