What is the voltage between two hot lines in a 208-volt AC system?

In a 208-volt AC system, the voltage between two hot lines (also known as phases) is indeed 208 volts. This system typically consists of three-phase power, where the voltage between any two hot lines is derived from the phase-to-phase voltage. In such systems, the nominal phase voltage is typically 120 volts. However, when measuring the voltage between two hot lines, the calculation is based on the configuration of the system.

For a three-phase 208-volt system, the voltage between two hot lines is not simply twice the single phase voltage of 120 volts but is a specific measurement associated with the phase configuration. Therefore, when taking the measurement between two phasing lines in a 208-volt system, it corresponds to the rated value of 208 volts.

This is an important concept for anyone working with electrical systems, as it underscores the distinction between phase-to-neutral and phase-to-phase voltage in AC systems.