I am working on evaluating existing distribution in a building but had a question about the right way to size the main distribution switchgear.
The main switchgear feeds 8 panels. Each of these panels feed a section of the facility. The loads on each consist solely of lighting, receptacles, and large power tools that are used intermittently and only for a short period of time. Sizing everything up to the panels makes sense and is straight forward and is based on the attached load, but the primary switchgear that was installed is sized as the sum of the main OCP devices on every panel. This just seems unrealistic to me and it got me thinking about what is the right way to account for highly variable loads like this which are all but guaranteed to not run simultaneously.
The main switchgear feeds 8 panels. Each of these panels feed a section of the facility. The loads on each consist solely of lighting, receptacles, and large power tools that are used intermittently and only for a short period of time. Sizing everything up to the panels makes sense and is straight forward and is based on the attached load, but the primary switchgear that was installed is sized as the sum of the main OCP devices on every panel. This just seems unrealistic to me and it got me thinking about what is the right way to account for highly variable loads like this which are all but guaranteed to not run simultaneously.
