How To Install Low Voltage Landscape Lighting

Walter Green - General Manager
November 4, 2015

How To Install Low Voltage Landscape Lighting

Less daylight calls for illumination. You can also enhance the nighttime curb appeal of your home, while adding a measure of safety and security, by installing low-voltage landscape lighting. These exterior-grade fixtures are typically placed along walkways and driveways, but they're also ideal for illuminating steps, trees, stonewalls, fences and other prominent garden features.

Landscape lighting describes a large and varied family of outdoor lighting fixtures. Some landscape lighting systems operate on 'line voltage,' the 120-volt current from your house. For DIY installation, though, we highly recommend low-voltage systems that operate on just 12 volts. They're less expensive, easier to install, safer, and use less energy.

The low voltage lighting system consists of three parts:

  1. Power Pack (transformer) — supplies the electricity
  2. Low voltage cable — transmits the electricity
  3. Low voltage lamp — the source of light

The Power Pack plugs into a standard outlet, reducing the regular household current (120 volts) to a safe 12 volts AC and has an automatic timer allowing lights to go on and off at preset times. The cable is a weather-resistant, self-sealing, insulated stranded copper wire that is available in 16, 14, and 12-gauge sizes. The final component, the lamp, offers greater economy than a conventional 120-volt lamp.

Installation Tips

Putting in a typical low-voltage lighting system requires just three steps for installation: laying the cable, installing the transformer, and connecting the lights.

First, start by laying the light fixtures on the ground where you intend to install them. Typically the fixtures are placed 8 to 10 feet apart. Then, simply unroll the spool of low-voltage electrical cable and lay the cable beside the fixtures. If you come to an obstacle, such as a boulder, tree, or fence, you'll need to string the cable under or around it.

Now you'll need to use a square-blade shovel to cut a 2- to 3-inch deep trench along the line where you want the light fixtures. Simply push the shovel into the ground and pull the handle back and forth to open a V-shaped trench. Then set the cable into the trench and push it all the way down to the bottom. Be sure not to use the shovel or other tool to press the wire into the trench, you don't want to accidentally slice into the cable.

A low-voltage cable consists of two insulated stranded-copper wires stuck together. Just peel the two apart so you have about 4 inches free for each wire. Then use wire strippers to remove about 5/8 inch of insulation from each side. Slide the wires through the retaining strap on the back of the transformer and then insert one wire under the A screw terminal, and the other wire under the B screw terminal. Now just tighten the screws securing the wires.

Next you'll need to drive a pressure-treated 2×6 stake into the ground next to an outdoor electrical outlet. Attach the transformer to the stake with galvanized or stainless-steel screws. Secure the cable to the stake with some insulated cable staples.

Connect the Lights Attach a plastic 'while-in-use' cover to the outdoor electrical outlet. This type of cover protects the outlet from rain and snow while still allowing easy access.

Now you need to plug the transformer's power cord into the outlet. Next, connect each light fixture to the cable. Most fixtures will come pre-wired with easy-to-use snap on connectors. Simply pinch the connector onto the cable. Since the transformer is already plugged in, the fixture should light up. If it doesn't, pull apart the connector and try again, or check the light-bulb.

Once you've connected the cable, stand up the light fixture and press its pointed stake deep into the ground. Be careful not to hit the buried cable. Check to make sure the fixture is straight, then move on to the next. Once all the fixtures are installed, simply close up the open trench.