DecksDirect.com

Wiring and Layout

Wiring gauge tells you exactly how much current the wire can carry. It's an inverse relationship: higher current runs on thicker cable, which is indicated by a lower number gauge. Wire should be purchased according to the type of light you have selected, the location of the lights and the wire layout.

Decide where you want to run your wires: stapled exposed under the handrail, hidden in a routered space within the railing, or under the deck and up each post. As current runs along the main cable to each light fixture in a circuit, voltage drop may occur, which can lead to insufficient voltage being supplied to lights at the end of your run. To limit voltage drop, it is recommended that for circuits with multiple light fixtures and/or long runs, you loop the main cable as illustrated in the first diagram below.

Loop Installation	Loop Installation: Light fixtures are arranged in a looped circuit, reducing the effects of voltage drop. DecksDirect.com recommends this installation type.
Straight Installation	Straight Installation: Also called a line installation, the wiring in this layout starts at the end of your lighting and follows the direct light fixture sequence, all the way to the transformer.
"T" Installation	“T” Installation: In this layout, the transformer is centrally located among the lights. This creates a more equal distribution of power but also requires a heavier gauge of wire (8 or 10 gauge) running from the transformer. This is a good layout for lighting that is a long distance from the transformer.
Split Load Installation	Split Load Installation: This wiring layout is recommended when light fixtures run in two or more directions from the transformer. For this layout, locating the transformer in the center of the run reduces the effects of voltage drop.