Understanding electrical symbols for house wiring

Understanding electrical schematic symbols may seem complicated at first, but if you can see the symbols on a chart or legend then you'll understand them when you see them on blueprints. These are the symbols for residential electrical wiring.

It's important to look at a floor plan to get a feel for the layout of the house. This will help bring a common sense approach to the electrical symbols on a floorplan.

For example, if you see a doorway on a floorplan, you'll know it's only common sense to have a light switch close by. Another example is a garage. Garages almost always require a 3-way light switch so the garage lights can be controlled from both ends of the garage and even inside the house.

It helps to be familiar with local codes as well. For example, the NEC says that modern kitchens need to have 2 gfci(ground fault circuit interrupter) circuit runs as part of the code. With that knowledge you would recognize the gfci symbol on the blueprints in the kitchen.

Sorry about the really fuzzy blueprint above. You can only shrink them just so much before they look like an ink blot.

Here are several more electrical symbols. Let's start with some outlet symbols.

Outlet symbols cover all outlets, but also tell where certain things are that have no outlet. For instance, a water heater has no outlet because it is hard-wired, meaning the wiring comes out of the wall, but is inside an armored cable and connects to the water heating cables inside the water heater panel box.

Here's some fixture symbols. Fixtures can be a lot of things, but typically a fixture is something that is considered a part of the house. If the house sells, the fixtures stay.

Here's some switch symbols. Switches are anything that controls an appliance or fixture.

And finally some communication symbols. Communication symbols refer to things like phones, doorbells, computer data wiring and security systems.