In a corner grounded 480V, 3-phase system, what is the voltage to ground from the ungrounded conductor?

In a corner grounded 480V, 3-phase system, the voltage to ground from the ungrounded conductor is indeed 480V. This system is designed such that it uses one grounding point (the corner) which means that only one of the phases is effectively grounded.

In a typical 3-phase system without grounding, each phase has a line-to-ground voltage that is equal to the phase voltage. For a 480V system, the phase voltage is the same as the line voltage since it is a three-phase system configured without a neutral. Therefore, if you measure the voltage from any of the ungrounded conductors to the ground, you would find it to be 480V.

The other voltages mentioned, such as 240V, 120V, and 600V, do not represent the voltage to ground in a 480V three-phase system with a corner ground setup. For example, 240V might be found in a split-phase system, while 120V is often associated with single-phase residential systems. The 600V figure does not align with the standard voltages typically seen in a 480V system. Thus, the correct understanding of the corner grounded system confirms that the voltage to ground