If my understanding is correct, with respect to dry-type building power transformers, due to the virtues of the transformer as a dumb machine it really doesn't care which side of itself is the primary versus the secondary. In other words a 480D-208Y tranformer can be correctly connected such that it steps up rather than steps down as they are designed to be used. The wrinkle I am told is the magnetization or inrush current; in a reversed application where a 208V 3ph connection is made on the primary side, giving a 480V three or four wire source on the secondary. It works great, except that where the magnetization current in the intended configuration is only a few times the full-load current of the transformer, in the reverse configuration it is something like a factor of seventeen. I can't recall for certain if what was said was specifically magnetization current or inrush current. The point was, one might have unforseen problems with any overcurrent device upstream of the transformer primary being able to handle such a sudden peak in current as such devices are commonly able to handle closer to six times the current without an instantaneous trip. I'm unclear on the dynamics of this sudden spike of current, is it only an issue when the transformer is first energized, or is it something that can be additive if say you were stepping up the load on a transformer in twenty percent increments. Another obvious implication lies in motor starting currents on the secondary side which I would imagine have their effects multiplied in some similar fashion. What are some effective ways of mitigating problems such as this?