Electrical Blueprint Symbols Glossary
Below is a figure showing the most often used residential electrical blueprint symbols.
For other residential symbols, see our Blueprint Symbols page.
Electrical Blueprint Reading
The most commonly used electrical blueprint symbols including plug outlets, switches, lights and other special symbols such as door bells and smoke detectors are shown in the figure below.
Note: Explanations for common household electrical items such as three-way switches and switched duplex plug outlets are below the figure.
Duplex Plug Outlet: A standard plug outlet with two sockets for plugs.
Split Duplex Plug Outlet: Typically used in kitchens or anywhere the loads on a given outlet will be high. The two sockets of the duplex outlet are on separate circuit breakers at the electrical panel. This decreases the likelihood of having two appliances which are plugged into the same outlet trip the circuit breaker.
Switched Duplex Plug Outlet: This outlet can be turned on and off with a switch. Often used for lamps.
Toggle Switch: A common light switch.
3-Way Switch: A bit confusing but this means there are two switches in the home to control the same item (typically a light or group of lights). For instance you may have two entrances to your living room and a switch at both entrances to turn the living room lights on. You'll need to use 3-way switches at both living room entrances for this electrical circuit to work. The term 3-way actually describes the inner workings of the physical switch which is different from a standard toggle switch.
4-Way Switch: As above with the three-way switch but here three switches will control typically a light or group of lights. If you had three entrances to a room, you may want a light switch at each entrance. For this circuit you will need to buy one four-way switch and two three-way switches.
Double Pole Switch: Typically used to switch outlets and appliances on 240 volt circuits.