Ivylog wrote:
Three phase power is 440V, not to be confused with 240V... two 120V legs. There are still a lot of CGs with just 30A power. They were more interested in dry camping and smaller campgrounds.
There are various standards for three phase power. Some campgrounds (not many) are wired with 120/208 three phase power, as are some apartment complexes and many commercial buildings. (In this system, of course, each of the three phases measures 120V with respect to the common neutral and 208V with respect to the other two phases.)
I think it's only relatively recent editions of the NEC that permit 120/208V power for 50A RV sites. For the average RV, it makes no practical difference since there are usually no 240V loads. The neutral current would be somewhat higher in general since the two legs aren't perfectly out of phase with each other, but still not exceeding either leg's current unless the power factor of the loads is pretty bad.