Wiring Diagrams and Symbols - Ask-The-Electrician Wiring Diagrams and Symbols for Electrical Wiring commonly used for Blueprints and Drawings. Not only do wiring symbols show us where something is to be installed, but what the electrical device is that will be installed.Switch Symbols · Lighting Symbols · Outlet Symbols · Panel Symbols · Communication Symbols Electrical Plan Meaning - Best Place to Find Wiring and Electrical Plan Meaning. The wiring diagram on the opposite hand is particularly beneficial to an outside electrician. Sometimes wiring diagram may also refer to the architectural wiring program. The simplest approach to read a home wiring diagram is to begin at the source, or the major power supply.