Find the symbol legend on the blueprint. The symbol legend shows you the path of wiring throughout the building and room by room. Find the number written by each wire on the blueprint. The number represents which breaker the appliance or light will run to.
Study the symbols associated with electrical wiring from the symbol legend. Standardized symbols are used on all blueprints. A straight line will symbolize the electrical wire. Letters are frequently found in circles to symbolize devices. An "A" inside a circle on the wiring diagram represents for an ammeter, a "V" in the circle is a voltmeter, a "W" is a wattmeter and a "G" is a galvanometer. Some symbols, such as electrical outlets, resemble the real device. See Resources for electrical blueprint symbols. Ask a certified electrician if you can't figure out what a symbol represents on the blueprint.
Look for room names on the blueprint. Each room has the same wiring pattern, but outlets and fixtures map out differently.
Check to see if all appliances have separate breakers. Decide if the blueprint shows phasing. Phasing is grouping lights and appliances in an area of a building on one line. This is a personal preference decision for the electrician.