In a closed delta configuration, with a 240 volt single-phase load, load current = I, one transformer current = I/root3 and the other two transformer have current = .732*(I/root3). So the current circulating in the transformer is not balanced between each of the three transformers.
With an open detla the transformers are different sizes (10kva and 15 kva) so the impedences will be different. But, since there are only 2 legs on the open delta (no circulating currents as in a closed delta), the currents will be the same thru each transformer (Kirchoffs current law). Essentially a simple series circuit inculding two transformers and a load.
Sound correct?
