This AutoCAD DWG file includes a complete Single Line Diagram (SLD) of a Distribution Board, showing circuit breakers, wiring connections, and load distribution for lighting, power, and mechanical systems. otect personnel by reducing exposure to major electrical hazards. As Distribution circuit SLD is a distribution circuit based command, the user must select a distribution circuit before running this command. If any. This course was adapted from the Department of Energy, Publication No. DOE-HDBK-1011/2-92, “Electrical Science”, Module 15, which is in the public domain. You will learn how to successfully read and analyze ACDB's single-line diagrams, wirings, and interlocking schematics.