Hello Juan, and welcome to ECN.
As I'm in the United Kingdom, I'm not sure of the following, but these are my thoughts:
As the 120/240V system is a 3-wire single-phase service, does anyone actually manufacture a 3-pole breaker so rated?
I'm not sure what rating breakers would be used normally on an American 120/208 service, but I don't see any reason why a 3-pole unit rated for a plain 240V shouldn't be employed.
Could one of our NEC/rating experts in the States please comment?
