Revit Electrical Panel Load Calculation Issues

I was recently exposed to an issue with electrical panel loads that illustrated what I feel are unique characteristics of how Revit circuit loads and Load Classifications affect the values that you see on the electrical panel schedule.  If everything is utilized in Revit exactly as Revit is designed and intended, everything works fine.  However, that rarely happens.  Engineering firms create and customize families, and change or set Load Classifications which can impact the proper loading calculations.

Many companies have electrical panel schedules which display the Loads Summary at the bottom of the panel.  This summary section separates each Load Classification into its own line so that you can see how much Connected Load exists for each different type of Load Classification and the Estimated Demand for each Load Classification.  Those load values are then displayed as the Total Connected Load and the Total Demand Load that should include everything on the panel.  The Total Connected Load is then displayed on a Switchboard panel schedule from which that panel is served.  There are many different variations of how this information is displayed, but the general process is the same.  Subpanels may also be involved, but the same issues exist with those loads.

In reviewing the issue, there were 2 different problems that were manifested in the panel loading.  This article is an attempt to describe those 2 problems to help others understand what may be happening when load numbers don’t add up.  I recommend everyone read the Autodesk Knowledge Network’s explanation of how Load Calculations are supposed to work.  Read it at About Load Calculations.

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Show Uncircuited Electrical Devices in Revit

When you have many electrical devices, light fixtures or other items in a Revit project file, it is easy to miss one getting placed on a circuit.  While un-circuited devices will display in the System Browser, it is nice to be able to have a quick visual check on a plan view for any of them.  We can do this through creating a custom View Filter.  The following image shows the impact of using a filter to show un-circuited items.

Uncircuited Receptacles

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Getting Revit MEP to Warn About Overloading Breaker

When creating electrical circuits in Revit MEP, it is helpful to utilize Revit’s ability to warn you when you are overloading the circuit.  The issue with utilizing this capability is that if you don’t use the proper process, it won’t work for you.  In essence, you must add electrical items to the circuit one at a time and also modify the proper circuit parameter.  We will walk through the process in this article.

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