Included in the electrical section are power and lighting plans, electrical diagrams, details, and schedules. Chapters 9 and 10 of the EA3 TRAMAN provide a discussion of interior wiring materials and the drawing of electrical plans.

Electrical single-line block diagrams are drawings that show electrical components and their related connections in a diagrammatic form. The diagrams, seldom drawn to scale, use standard symbols to represent individual pieces of electrical equipment and lines to represent the conductors or wires connecting the equipment.

Figure 4-3.Example of a power-riser diagram.

A simple example is the power-riser diagram shown in figure 4-3. In this example, you see the manner in which two electrical panels (L1 and L2) are planned for installation in a two-story building. As you see, notes are used to identify each piece of equipment and to indicate the number, size, and type of conductors in each conduit. A panelboard schedule for each of the panels should also be included in the drawings to indicate the components, such as fuses or circuit breakers, contained in the each panelboard.

A schematic wiring diagram is similar to the single-line block diagram; however, it provides more detailed information and the actual number of wires used in each circuit is shown. Complete schematic wiring diagrams are usually used for unique and complicated systems, such as control circuits. An example of a schematic diagram is shown in figure 4-4.