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In many commercial/industrial panels there will be 3 phase, 2-120v to ground legs, and 1-208v to ground leg, but they will measure 208 volts between each hot leg.
Can't happen. Not in one system.

The first scenario (2 x 120v and 1 x 208) is a center-tap-grounded Delta or open-Delta, period. 240 line-to-line, and don't use the high leg (208v) for line-to-neutral loads.

The second (3 x 120v) will be a 208v hot-to-hot Y system, period. All three hots will measure the same to neutral (and thus, to ground).

Larry Fine
Fine Electric Co.
fineelectricco.com