What is the permitted load demand factor for four or more appliances that are fastened in place?

For four or more appliances that are fastened in place, the National Electrical Code (NEC) allows for a load demand factor of 75%. This factor recognizes that when multiple appliances are used together, the total load does not necessarily equal the sum of the individual loads. Instead, a demand factor accounts for the likelihood that not all appliances will operate at full capacity simultaneously.

This demand factor is important in sizing service and feeders because it allows for more efficient use of the electrical system. By applying the 75% demand factor to the total calculated load, electricians can minimize the amount of installed capacity while still adequately serving the expected usage.

Understanding the application of demand factors is crucial for compliance with NEC and local codes, and it ensures safe and reliable electrical installations. In this case, selecting the 75% factor reflects the accepted practice for calculating the load when dealing with multiple fixed appliances.