Low-Voltage Outdoor Lighting

Overview

Low-voltage outdoor lights provide a pleasant alternative to glaring floodlights. They can be strategically positioned to accent the plants and features you want to highlight. They can be used for safety—to illuminate paths, steps and dark zones. When artfully placed, they can be as beautiful and natural looking as the landscape itself. And since they're low voltage (you can literally add wires and lights to the system while it’s operating), they're safe to use and install. Here we'll show you the special tips and tricks the pros use to install them.

Selecting the right design and components

Walk into any home center or garden center this spring and you’re guaranteed to run into a towering display of low-voltage lighting. You’ll find $69 prepackaged sets and $100 individual lights; plastic fixtures and metal ones; lights you can shine down from trees and up from ponds. The bottom line is, you’ll get what you pay for. We decided to pay about $90 apiece for metal “architectural grade,” low-voltage halogen lights. The halogen bulbs cast a whiter, more focused beam than standard lights—almost like natural sunlight. And the bulbs last longer, some up to 10,000 hours. The metal construction of the fixtures means greater longevity for them too, and we loved the natural burnished look.

As you design and shop for your lighting system, keep in mind:

• Buy a larger transformer than you’ll initially need so you can add lights later as your landscape (and imagination) expands. If you’ll be installing 400 watts of lights, buy a 600-watt transformer.
• Avoid over lighting. Outdoor lights look best as accents, broadcasting pools of light. Flooding sitting or planting areas with “stadium lighting” can make them look washed out.
• When lighting a path, decide whether you want to light only the path or both the path and the features around it. As a rule, the broader the field you want to light, the higher the light pole you’ll need. Path lights with a 20-watt halogen bulb at a 24-in. height should be spaced every 10 ft.
• Consider seasonal factors. Install lights where they won’t be easily damaged by plows or shovels. And bear in mind that some plants, like hydrangea bushes, sumac and dogwoods with colorful stems, look cool lit up, even when they’re leafless.

Install the lighting components

Pro tips for better design, layout and installation Take the time to install your lights correctly and they’ll last longer, cast more light where you want it and require less maintenance. Get a first-class installation using these tips:

• If your lights come with press-on fittings—the type that bite through the insulation and into the wire to make their connection—cut them off and use the wire connectors shown in Photo 4. Your connections will be more solid and longer lasting.
• The farther a light is from the transformer (and the more lights installed between it and the transformer), the less light it will put out. Avoid this “voltage drop” by creating a tee (Fig. A) and running two short lines rather than one long one. A good rule of thumb is to put no more than 100 watts of lighting on one line. If you want to put ten 20-watt lights on a circuit, make a tee connection with five lights on one line and five on the other. You can also minimize voltage drop by using a thicker gauge wire.
• Always leave a little extra wire as you hook up the lights. This will give you the freedom to move a light after you’ve hooked it up for testing or after you’ve installed it.
• Burying the wires should be your last step. Lay everything out, hook up your lights, test your voltage, and look at your results at night before burying the lines.
• Purchase a transformer with a built-in photocell and timer. Orient the photocell with some western (sunset) orientation so it doesn’t turn lights on too early.