What is the demand factor for marina load calculations of 45 shore power receptacles?

The demand factor for marina load calculations is typically determined based on the total number of shore power receptacles available and the expected usage. In this case, with 45 shore power receptacles, the demand factor is set at 50%.

This value is derived from industry standards and practices that account for the fact that not all receptacles will be in use at the same time. For marinas, the 50% demand factor reflects the understanding that during peak times, it is reasonable to expect that only half of the total available receptacles will be actively drawing power simultaneously. This helps in calculating the overall load that needs to be managed and ensures that the electrical systems are adequately sized without being oversized for the actual anticipated demand.

The choice of 50% for this particular situation allows for both safety in capacity management and economic efficiency in installation and operation, adhering to the principles established by the National Electrical Code (NEC) and local regulations. Understanding the rationale behind these demand factors is crucial for electrical design, especially in environments like marinas where variability in usage patterns is expected.