For many electrical designers using Revit for their construction documents, the home run arrow for circuits is an important part of their drawings. When multiple circuits are part of one home run, the designer wants to show multiple arrowheads on the circuit leader. This is an easy task to accomplish in Revit.
It is now the end of another year, with all the experiences of life that comes with that year. As such, we tend to evaluate the past year and look forward to the challenges and experiences of the new year. That includes all different aspects of our lives, including the personal and professional sides. However, in additional to individuals doing this, organizations need to do the same thing.
Since this is an building industry oriented blog, I am going to touch on what I believe to be an important component of AEC firms in the technological age in which we now live. That is the evaluation of Building Information Modeling (BIM) within your firm. While there are still many AEC firms that have not moved into the world of BIM, it is becoming more common and more important in the industry.
It is extremely important to evaluate BIM within a firm. There are costs associated with moving toward BIM integration and it is important to understand whether your firm is getting a return on that investment and how it can be improved.
When using Revit for electrical design, using Panel Schedules should be an important part of your design process. Revit provides the user with some default panel schedule templates with the software, but most organizations modify the templates to function and appear the way that they desire. Revit allows the user to do quite a bit of customization to the templates, but be aware that there are still limitations to the customization ability and some nuances.
Revit Help has instructions for basic electrical template modification. In this article, we will look at some aspects of customizing a template that are not so obvious to the user.
If you are utilizing Revit for electrical engineering design, then you are using electrical panels and likely electrical panel schedules. While the process of inserting electrical panels and connecting basic circuits to them is pretty straightforward, there are some items that are good to know to help you better utilize panels and their associated schedules.
First off, a requirement in this process is to make sure that after you place an electrical panel in the Revit model, you set the Distribution System for it. Otherwise, you will not be able to connect any electrical device or other electrical equipment to the panel. The Distribution System is shown in both the panel’s Propertiespalette, and on the Options Bar on the ribbon.
Panel Schedules in Revit are a report of the information that is contained in the electrical panel, and schedules cannot be created without having a panel family placed in the project file. They are not like a spreadsheet where the numerical values are entered into the spreadsheet. The values shown in the panel and on the panel schedule are a result of connected loads to the panel and are only as good as the information in the items connected to the panel.
Autodesk Revit includes the ability to define enclosed areas within the building as Rooms or Spaces. While both items allow the user to assign a name and number to the area, they have different purposes and parameters for information within that designated area. To put it in the most basic of terms, Rooms are for Architects, Spaces are for Engineers.
I have talked with engineers that don’t believe that they have any need for Spaces. They believe that using the Rooms in the architect’s model works just fine for them since all they care about is having a tag on the view that shows the room name and number. If the engineer simply tags the architect’s Rooms, then the names and numbers will always be up to date. This is a very narrow-sighted view of the purpose of Rooms and Spaces.
As I work with electrical engineers who are migrating to Revit, a common question that I get is “How do I create one-line diagrams in Revit”. One-line diagrams, also called single-line diagrams, are an important part of electrical drawings for construction documents, so it is a subject that needs to be addressed. They are a simplified method of representing a 3-phase power system that shows distribution boards, switchboards, transformers, panels, breakers, etc., with lines illustrating the connectivity of the components of the distribution system. The diagram is not just for physical construction of the building’s electrical system, but developed by the electrical engineer during early stages of design.
The problem that you run into with creating one-line diagrams inside Revit is that the one-line diagrams are generally created before the equipment is actually placed in the Revit model. The electrical engineer will design the building’s electrical system by developing this diagram, then placing the electrical service equipment based upon the diagram.
Unfortunately, Revit does not provide a way of coordinating the one-line diagram with the actual electrical components placed inside Revit, either before the electrical equipment is placed or after the equipment is placed in the model.
Architects and Engineers that collaborate on projects using Revit will typically link their models together to see the other discipline’s design within their model. Part of that process often includes one discipline using the Copy/Monitor function within Revit to copy specific model items from the other discipline’s model into their own model. Revit has a new twist on the coordination review feature when you monitor items between different project files.
(Please note that this article only addresses the new twist and does not explain the process of linking files or using the copy/monitor function.)
If you are using Revit for electrical design, sometimes you need a piece of electrical equipment to have more than one feed but carry the same load. A common situation for this is an Automatic Transfer Switch (ATS) where it is fed through both the primary electrical system and an emergency backup system powered by a generator. Downstream panels served by the ATS will receive power from both the primary electrical system and the emergency power system.
This is possible through having 2 electrical connectors on the electrical equipment family. Each connector can then be connected to the appropriate electrical system and show the same load.
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.
Revit 2016 has been released and you can find various sources for information on the enhancements of the software. There are lots of nice changes, but I want to focus on electrical enhancements. Some were part of the UR2 release of Revit 2015 available to subscription users, but are included in Revit 2016 for all users.
Electrical panel schedules are a very important part of designing and documenting the electrical portion of a building project. The electrical panel schedules help with designing the electrical system by showing the power requirements on the panel to the designer and allowing the designer to spread the power requirement across the poles of the panel. It is also useful for showing the electrician how to circuit the items assigned to the panel. Those 2 different purposes may involve showing slightly different information on the panel schedule. In addition to that, the facilities manager may even desire to see different information on the panel schedule.