Which voltage is associated with a standard 7200 3-phase 3-wire system?

In a standard 7200 3-phase 3-wire system, the voltage designation refers to the phase-to-phase voltage. In a three-phase system, the voltage is typically measured between any two of the three phases, providing the full voltage supplied to the load. For a 7200 system, it indicates that the line-to-line voltage (phase-to-phase voltage) is 7200 volts.

In this context, it is important to remember that a 3-phase 3-wire system does not have a neutral wire, and thus the phase-to-ground voltages are not typically referenced in this system. The phase-to-ground voltage would actually be lower than the phase-to-phase voltage and is not what the standard rating primarily describes.

Understanding that the phasing in this system optimally utilizes the voltage provided between phases and is set up for equipment that operates at this level is vital for lineman apprentices. The line-to-ground voltage would be approximately 4150 volts, which is not the standard reference provided in this question.

This perspective clarifies why the focus remains on the phase-to-phase voltage in identifying the standard measurement within this 7200 system. The "primary to secondary" reference typically applies to transformer ratings, which does not fit within