The minimum ampacity for a feeder supplying ten 30A shore power receptacles in a marina is?

To determine the minimum ampacity for a feeder supplying ten 30A shore power receptacles in a marina, it's essential to consider the demand load and how it applies to the overall calculation based on the National Electrical Code (NEC).

The total demand for the receptacles can initially be calculated by multiplying the number of receptacles by their individual rating. In this case, ten receptacles at 30 amps sums up to 300 amps. However, NEC allows for demand factors when calculating feeder loads, especially for receptacles that may not all be used at their full capacity simultaneously.

According to NEC guidelines, for certain applications such as marinas, calculations can employ demand factors that allow adjustments; generally, you can use a percentage of the total calculated load depending on the number of outlets being served. This means the calculated total does not have to match the full load of every receptacle. Typically, when examining multiple receptacles, not all will be used at the same time, allowing for a reduction in the overall required ampacity.

For this specific case, employing demand factors or loading adjustments as described in NEC articles related to feeder calculations for marinas leads us to determine an appropriate minimum feeder ampacity. A common practice is to apply adjustments so that the