What is the minimum demand load required for general-purpose receptacles in an office building with 150 receptacles?

To determine the minimum demand load for general-purpose receptacles in an office building, a specific calculation based on the number of receptacles is used, typically following the National Electrical Code (NEC) guidelines. For general-purpose receptacles, the NEC provides a demand factor that can reduce the calculated load based on the number of receptacles installed.

In this scenario, with 150 receptacles, the demand calculation would involve applying a certain VA per receptacle to the total number. The common rule suggests a demand factor of 180 VA per outlet for the first 10 receptacles and then 120 VA for each additional receptacle thereafter.

Using this approach, the first 10 receptacles would contribute 1,800 VA (10 x 180 VA), and the remaining 140 receptacles would contribute 16,800 VA (140 x 120 VA). Adding these together gives a total demand load of 18,600 VA.

However, when rounded down as per common practice, this falls to a minimum demand load of 18,500 VA. This represents a practical application allowing for some percentage of receptacles to not be fully loaded at the same time, which is typical in office environments.

Thus, the figure of 18,