Plate 254:  Dividing the equipment wiring and the power-and-control wiring
(This plate added NOV 2003)

Three point motors have now been fully wired to the power distribution center. If you examine the top rows of each of the three terminal blocks in the accompanying picture, you will see that wires are attached to columns 1, 2 and 3, but that columns 7 through 10 are as yet unwired. The wiring in the top row of each block is called equipment wiring, because the upper-row wires are connected directly to equipment in the layout, such as point motors. The wiring in the bottom row of each block is called power and control wiring, because the lower-row wires are connected to power and control apparatus, which can be located at a distance of several feet from the layout. Two examples of power and control apparatus are train controllers and lever switches. We introduced the distinction between equipment wiring and control wiring in Plate 251. --more--

Observe in the accompanying picture that the power-distribution wiring has been separated into two separate "flows". One set of wires "flows" to the right, toward the layout. These are the equipment wires, which are attached directly to layout equipment, such as point motors. The other set of wires "flows"downward, away from the layout. These are the power and control wires, which are attached to AC binding posts and lever switches. The reason we see two separate "flows" is that the power and control apparatus will be concentrated within a power and control center, which is entirely separate from the layout, and indeed will normally be located several feet away from the layout in a specially-designed housing. Go to top of page