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. A distribution board diagram gives the blueprint for the electrical wiring before any physical installation is done. This guide covers split load vs dual RCD vs RCBO board configurations, circuit arrangement and allocation, BS 7671 labelling requirements, type testing under BS EN 61439, SPD installation, wiring best practice, and the common. The Distribution box system diagram mainly includes the following parts: Incoming line part: Displays the incoming line source of the distribution box, which may be a single-line incoming line or multiple-line incoming lines (such as normal power supply and backup power supply), and marks the.