On a common three-phase, four-wire service, what should the voltage be between any phase and neutral?

In a common three-phase, four-wire service, the standard voltage between any phase and neutral is typically 120 volts. This configuration is prevalent in residential and light commercial electrical systems in North America. The three phases provide a balanced load, while the neutral serves as a reference point and return path for current.

The 120 volts obtained between any phase and neutral comes from the fact that the system is designed to provide appliances and lighting with a suitable voltage for operation. In a standard three-phase system, the line voltage between any two phases is higher—specifically, for a 120/208 volt system, the voltage between any phase and neutral is consistently at 120 volts.

The other voltages listed—105 volts, 208 volts, and 220 volts—do not represent the standard relationship between phase and neutral in this context. While there are other voltage configurations that may include those numbers depending on the specific system design, for a common three-phase, four-wire service, 120 volts is the correct and expected value between any phase and neutral.