Fig. 826. Circuit diagram illustrating names of the various parts. A circuit may consist of the following parts as defined in the accompanying text: 1, feeder, 2, sub-feeders, 3, mains, 4, branches, 5, taps. It is well to clearly distinguish between these divisions because the terms are constantly used in wiring.
A main is a stretch of wiring supplied from one or more feeders or sub-feeders and distributing current to a number of taps, or else to a number of branches.
A branch distributes current among a number of lamps, etc.
A tap almost invariably delivers current to a single lamp or other device.
Reference to [fig. 826] will make these definitions clearer. This diagram is intended merely to illustrate the above definitions and does not represent any special plan of wiring.
Figs. 827 and 828. Simplest forms of circuit, consisting of a main with one or more lamps at the end. The smallest size wire allowed (No. 14 B.&S. gauge) will generally be found amply large for such circuits. Note carefully the difference between a main and a branch by comparison with [fig. 826]. A main begins from a fuse block, while a branch is an offset from a main without any fuse block.