Successful Instrumentation and Control Systems Design

Panel arrangement drawings depict equipment that is mounted on back panels inside electrical enclosures and show any front-panel penetrations. These arrangements accomplish several things:
They convey construction detail about the contents and placement of front-panel equipment such as control switches and lights.
They convey construction detail about the contents and placement of back-panel equipment.
They show the placement and contents of any engraved labels.
They provide a bill of materials for each item in the panel that must be purchased.
They allow the external enclosure (i.e., "the can") to be sized with confidence.
The anatomy of the drawing is very simple. It should show a graphic of the panel, usually on the left side, and a bill of materials, usually on the right. It is strictly a physical drawing showing the relative locations of the items in the panel. Graphic detail should be minimized, and no wiring detail need be included. Usually, a general "not to scale" arrangement is sufficient provided the designer is sure that any potential conflicts have been identified and scrutinized and any front-panel penetrations have been sufficiently detailed.
One quick initial design method for creating these drawings uses Microsoft Excel as a design aid. Following is a procedure for turning your Microsoft Excel spreadsheet software into a design tool:
Turn the spreadsheet into a sheet of graph paper
Open a new spreadsheet and click on the blank cell at the junction of the row labels and column labels. This selects the entire spreadsheet...