Δ-connected systems can be solidly grounded using a few methods. One method of grounding a three-phase, three-wire, Δ-connected system is to ground one of the phase conductors.
This creates a three-phase, corner-grounded system, sometimes referred to as an end-grounded system. The phase-to-phase voltage of a corner-grounded system is also the phase-to-ground voltage of that system. For example, the phase-to-phase voltage of a 480V delta system is 480V. If one phase is grounded, the phase-to-ground voltage from the other two phases is 480V.
In this case, the voltages are as follows:
Between phases 480V.
Flip on the SPST switches to turn on primary high voltage.
