All 15A, 20A, and 30A, 125V receptacle outlets that are not a part of the permanent wiring of the building or structure shall be equipped with GFCI protection. If a 15A, 20A, or 30A, 125V receptacle ...

It’s helpful to look at an example problem. What’s the demand load for a 120/240V, single-phase service required for a marina with twenty 30A, 250V receptacles and twenty 20A, 125V receptacles (Fig. 1 ...