What is the minimum required size for a 120/240 volt service for a marina with multiple 30 ampere, 120 volt receptacles?

The minimum required size for a 120/240 volt service for a marina with multiple 30 ampere, 120 volt receptacles can be calculated by considering the total load it must support. Each 30 ampere receptacle can supply a total load of 30 amps, and if the marina has several of these receptacles, the total amperage needed will rise accordingly.

To find the minimum service size, first determine the total number of 30 amp circuits intended to be installed. If there are, for example, 10 receptacles, the total load just from those would be 10 circuits times 30 amperes, which equals 300 amperes. However, in this type of situation, applying demand factors from the National Electrical Code (NEC) might allow for a reduced service size, but generally, for individual receptacles used in marinas, it's a common practice to size the service based on the maximum potential load.

Considering a typical marina setup, the service needs to accommodate the simultaneous use of these receptacles. Thus, calculating the necessary capacity must not only reflect the continuous load but also adhere to safety and code requirements for future growth and possible additional loads.

The chosen answer of 288 amperes makes sense if we analyze