The Electrical Code

215.5 Diagrams of Feeders. A feeder diagram is a drawing of what feeders are ran and were they go. They might or might not detail the exact route they take but they will show the room they are ran to what ever device they are feeding.This code has to do with when the electrical contractor stands for one of his or her inspections. Feeder detail will show the inspector what size wire, type of wire enclosure, and breaker used. It might also show the demand that the device needs to operate. The square footage is needed to give the inspector the correct calculation for the size of the service, size of the HVAC, sub-panel location and size and what that sub-panel is feeding. It will also show the demand factor that is needed to make a predictable load amount on the main and sub-panel.

If you are a home owner and you are building a single family home not attached to any other structure, you can stand for this inspection and save some money by not having the contractor be there waiting for the inspector. A lot of contractors price that in and you need to make sure that it make financial and responsible sense to do this. Let me be clear town officials might not allow this because you might be attached to another dwelling that can be affected. So make sure that your saving enough money by doing this and be well versed in the code that your standing for. I am only talking about electrical contractors.

“If required by the authority having jurisdiction, a diagram showing feeder details shall be provided prior to the installation of the feeders. Such a diagram shall show the area in square feet of the building or other structure supplied by each feeder, the total calculated load before applying demand factors, the demand factors used, the calculated load after applying demand factors, and the size and type of conductors to be used.”