<P> A wiring diagram is often used to troubleshoot problems and to make sure that all the connections have been made and that everything is present . </P> <P> Architectural wiring diagrams show the approximate locations and interconnections of receptacles, lighting, and permanent electrical services in a building . Interconnecting wire routes may be shown approximately, where particular receptacles or fixtures must be on a common circuit . </P> <P> Wiring diagrams use standard symbols for wiring devices, usually different from those used on schematic diagrams . The electrical symbols not only show where something is to be installed, but also what type of device is being installed . For example, a surface ceiling light is shown by one symbol, a recessed ceiling light has a different symbol, and a surface fluorescent light has another symbol . Each type of switch has a different symbol and so do the various outlets . There are symbols that show the location of smoke detectors, the doorbell chime, and thermostat . On large projects symbols may be numbered to show, for example, the panel board and circuit to which the device connects, and also to identify which of several types of fixture are to be installed at that location . </P> <P> A set of wiring diagrams may be required by the electrical inspection authority to approve connection of the residence to the public electrical supply system . </P>

Which of the following is not a feature of a good wiring design