Wiring diagrams also known as connection diagrams do not contribute to the understanding of the operation of the equipment. The purpose of wiring diagrams are to provide the installer with the information required for terminating the individual conductors at various points. Wiring diagrams fall into two general categories: connection diagrams and interconnection diagrams.
A connection diagram generally shows the electrician how to connect individual components within a common enclosure, such as a relay cabinet or a control panel. In order to do this; each device is shown symbolically with all terminal boards shown. The identification numbers of all conductors are shown where they are terminated. There are two systems that are usually used: one where lines are drawn to represent each conductor and one where only the conductor identification number is shown. Either system is acceptable as long as the desired information is adequately presented. Connection diagrams are developed from the information given on the elementary diagram.
Interconnection diagrams are drawings that show the conductors that are used to interconnect various components of an electrical system. It shows which conductors are to be connected to which terminal and must be closely coordinated with the schematic and connection diagram.