It seams different utility co vary in there distribution norms . In the Centerpoint (utility co)of course 120/240 single phase is the most common, next is 120/240 open delta, with 120/240 delta and 480/277 Y next. Rare is 120/208 y. Some motel drops but most 120/208 is from customer owned transformers with 480 drops. Of the 100+ commercial customers in Centerpoint territory none have 120/208. Now in Entergy (utility co.)territory (north of Houston) again 120/240 single phase is most common, followed by 120/208 y then 120/240 open delta, then 120/240 delta & 480/277Y. My shop is in Entergy territory and is served by 120/208 y although I have only 120/208 single phase serving my suite.
