Discover the intricacies of electrical drawings and uncover the meaning behind the symbols, abbreviations, and designators used in these technical diagrams. Learn how these details facilitate clear communication for engineers and assist in compliance with building codes and energy consumption regulations.
Key Insights
- Electrical drawings include essential details such as electrical symbols, abbreviations, lighting fixture schedules, construction notes, and mounting heights for outlets. These details ensure clarity for all project stakeholders and aid in the accurate installation of electrical components.
- Each element in an electrical drawing serves a specific purpose, for instance, detail references indicate where a certain detail appears first and subsequently, while noting designators, provide further information about a specific element. These details are critical in ensuring accuracy and adherence to specific standards in electrical installations.
- The electrical panel schedule, present in the drawings, provides detailed information about the panel box including breaker numbers and power demands. This information is instrumental for the electrical installer to understand how the electrical system is designed and to ensure proper installation accordingly.
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Let's begin looking at the electrical drawings for this project. This is the E1.0 page, which is essentially the electrical cover page. You can see that we have a few things going on.
We have a listing of electrical symbols, abbreviations, a lighting fixture schedule, some details, and general construction notes. So let's look at our electrical symbols for a second. You can see that what's going on is that once again we have our detail references.
So you're seeing that on top is the detail number. You can see that this is the page on the bottom right where the detail is appearing, and on the left hand side is where the initial detail appears. We can see some noting designators.
We also see mounting height above finish floor. Believe it or not, there are some standard heights that are frequently used for installing outlets, which are usually like 18 inches above the floor. And then you have the higher outlets that might be, for example, the outlet that's above the counter in the kitchen.
When heights are not standard, we designate those. So these symbols that are being shown are relatively typical in electrical drawings, but the engineers want to make sure that everything is clear to everyone who is working on the particular project. We also have standard abbreviations.
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And then if I go down and look at my lighting fixture schedule, you can see it's a matrix that's relatively similar to what we had on the mechanical. We have our call-out symbols. They're designating the room in which it's located.
They're talking about the mounting. Is it attached to the ceiling, to the wall, under the cabinet? Where is it being located? There's information that's being provided regarding wattage and the lumens that are being used by the particular equipment. And then luminaire description means a description of the actual fixture itself, who's making it, input requirements, and so on and so forth.
And then we also have the symbol that's being used for that particular piece of equipment. So again, this information is not only for this project, but it's also to help the Title 24 engineer when they're doing their analyses on information such as energy consumption within the building. The details that are going on here, I'm just going to zoom into the photo cell control diagram.
You can see that once again, here is the actual name of the detail down here. You can see it's occurring for the first time on page E1. And then we have the different sheets over here on which this symbol is being used.
You can see the callout designator, and there are some notes. But again, everything is referencing back to the overall sheet, and our construction notes are talking about how to install. So again, we're just ensuring that when the information is installed in the building, that is installed per the building code.
If I go to the next page, the E2.0, which is for this particular dwelling unit. Again, I'm going to zoom in. You can see the callout that's happening right here.
We have outlets, television, telephone. All of the mounting heights are standard. If I look over here in the kitchen, you can see that they're saying that this outlet right here is plus 66, which means 5'6 above the finished floor.
And this is where the refrigerator would typically plug in. And you can see other callouts that are going on around the kitchen. This fan, we are calling out that it needs to be in a particular area.
Generally, electrical drawings are representative. We're saying, put the outlet in adjacent to the nearest stud. But whenever we have electrical items that need to be in a particular location, we dimension where those items need to be.
In this case, it's a ceiling fan. If you were working on an office building where you were installing, for example, systems furniture, the designer will choose where the furniture is going to go. The furniture, the systems furniture, comes with pre-installed electrical outlets and junction boxes.
And so we need to also provide electrical outlets in specific locations to correspond to where the junction boxes are on the systems furniture. So again, in that kind of a commercial project, we would dimension where the outlets need to exactly go. So you can see we have this lighting fixture over the dining room table, and we're calling it out as being 4' away from the adjacent wall.
There's additionally a matrix over here. This is an electrical panel schedule. This is talking about what's going on in your panel box.
And so we have breakers. We have breaker numbers. And this is saying, for example, that in the electrical panel box, the power that is feeding the smaller appliances in the kitchen are located on circuit number 9. You can see power demands that are being utilized by the breaker box itself.
So again, what we're trying to do is to provide the appropriate information so that when the electrical installer is actually installing the electrical panel, they can know how the engineer has designed all of this information to be presented for construction.