DOE-HDBK-1016/1-93 Electrical Diagrams and Schematics ELECTRICAL DIAGRAMS AND SCHEMATICS Types  of  Electrical  Diagrams  or  Schematics There  are  three  ways  to  show  electrical  circuits.  They  are  wiring,  schematic,  and  pictorial diagrams.   The two  most commonly  used are  the wiring  diagram and  the schematic  diagram. The uses of these two types of diagrams are compared in Table 1. TABLE  1 Comparison  Between  Wiring and Schematic  Diagrams Wiring Diagrams Schematic Diagrams   1. Emphasize connections between elements of a circuit or system   2. Use horizontal and vertical lines to represent the wires   3. Use simplified pictorials that clearly resemble circuit/system components   4. Place equipment and wiring on drawing to approximate actual physical location in real circuit   1. Emphasize "flow" of system   2. Use horizontal and vertical lines to show system flow   3. Use symbols that indicate function of equipment, but the symbols do not look like the actual equipment   4. Drawing layout is done to show the "flow" of the system as it functions, not the physical layout of the equipment The  pictorial  diagram  is  usually Figure 9   Comparison of an Electrical Schematic and a Pictorial Diagram not found in engineering applications for the reasons shown in the following example. Figure     9     provides     a     simple example    of    how    a    schematic diagram  compares   to  a  pictorial equivalent.    As  can  be  seen,  the pictorial  version  is  not  nearly  as useful as the schematic, especially if    you    were    trying    to    obtain enough   information   to   repair   a circuit     or     determine     how     it operates. Rev. 0 PR-03 Page 9