Symbols

- [Instructor] Just like any other blueprint reading, you should become familiar with the symbols that are used on the particular set of blueprints that you are working from. Often, designers and engineers use different shapes and symbols to identify like items. In other words, one engineer may use a rectangle to identify a light fixture, but a different engineer using a different drawing program may use a circle to identify light fixture. That's why it's so important to look at and familiarize yourself with your symbols. Let's take a look at a symbol list drawing. And some of the specific symbols used for this particular project. Go in a little bit on this and take a look. You could see the symbol used for duplex receptacle. That's very common. A quad receptacle, cord reel. This is interesting. You see this subscript. Here's a receptacle, but CTR means it's a countertop receptacle. Going down the list, you'll see a bunch of different symbols for different items or details on the drawing. The S with a line through it, is for a single pole toggle switch. The S with a four is for a four-way toggle switch over to the right. We've got pictures for a surface mounted panel, a flush mounted panel, here's an interesting one, the arrow with the letters after it, stand for a branch circuit. It's a home run, so what they're telling you is the circuits probably going back to its designation or source such as the panel and those letters or numbers could be the circuit designation. Down here are some fixtures. Wall mounted, these ones are ceiling mounted. You'll notice again a subscript letter. The letter indicates the type of fixture. Over here you'll see it says to see the luminaire schedule. We'll get to that in just a minute. Going further down, you'll see more different types of fixtures. These squares with the letters in them stand for manhole and handhole. Let's go back over here to these symbols. Here you see some circuit symbols like a fuse, contacts, circuit breakers. You'll see most of these in one line in wiring diagrams. We'll get to those later to. Look at these communications outlets. They're shaped the same but one's colored in. If you look to the right, the description tells you what the difference is between the two. Going further down you'll see some more circuit type symbols like a transformer or a motor or disconnect switch. Again, you'll find these more in the wiring diagrams in one line diagrams. That's most of the symbols used for this particular project, although larger projects may have many, many more symbols in many different symbols as well. Going further down on this drawing, you'll see a list of abbreviations. Let me get a little closer. Here you go. AC, for instance, stands for above counter. Perhaps a receptacle or switch is being installed and the designer wants to make sure we're installing it above the counter. EF, exhaust fan. We may be wiring up an exhaust fan. Sometimes the designer doesn't want to use all these long words and congest up the drawing. That's why they use the abbreviations. KVA, Kilovolt, PB pull box, possibilities are really endless here. The important thing is to know what the abbreviations are. If you see something on the drawing and you're not sure, revert back to the abbreviations. One last note while we're on this drawing, you're going to see that, let me scroll over here. It looks like there's some notes on this drawing. The symbol and abbreviation Drawing is one of the first drawings in a whole set of electrical drawings and schematics. It looks to me like all of these notes are general notes that apply to all the drawings. This is very important. You should read and understand all of these when you're building or even estimating the project. Go through all of them and see how they apply to the particular system that you're working on.