This AutoCAD DWG file includes a complete MDB single line diagram showing circuit breakers, feeders, incomer, metering, and outgoing distribution arrangement. Clear wiring diagram for residential electric meter box, showing connections, safety components, and layout for accurate installation and maintenance. Based on the electrical installations specified in the floor plan, electricians can use it to create a. A Single Line Diagram (SLD) of the Main Distribution Board (MDB) provides a clear representation of an electrical power distribution system using simplified symbols and line connections. A distribution board or distribution box is where the main power supply is distributed to multiple loads.