How to Install Low Voltage Outdoor Lighting


Provide a dramatic accent to your gardens and walkways and save money in the process. If you are a do-it-yourselfer, installing your own low voltage outdoor lighting is easier than you think. These instructions will help you be successful and give you an outdoor lighting installation you’ll be proud of and that may even add resale value to your home. All of the supplies you’ll need to do this job are listed here. Tools required are Phillips screwdriver, sledgehammer, wire cutters and a shovel for digging. I’ve got more information about how to choose a transformer below.


Make sure you have a GFCI receptacle outside. If not, install one yourself or get one installed. This is a necessary first step. If you don’t have one, unless you are comfortable with doing electrical work you should hire an electrician to install one for you.


Create a plan – walk your property with a long tape measure (if you don’t have one, purchase a 50-100 foot tape measure to make this easy), a drawing pad and pencil and your imagination! This is where you’ll decide what kinds of fixtures you want to install and where. A plan will insure that you buy the right amount of materials and fixtures, so don’t skip this one (unless you’re only going to be installing one post light and even then you need to know how much cable to buy).


Purchase what you need to get the job done. You will need to buy a transformer, preferably with a timer, cable, the light fixtures themselves and metal ground stakes. To size your transformer, add up the watts for each fixture, and then figure in extra wattage for future projects. So, if your fixtures are each 18 watts and you have 10 of them, that’s 180 watts for your transformer plus 25% more for the cable. Add onto that some extra voltage for future growth and you’re looking at probably a 300 watt transformer.


From your plan, determine the length of each run between fixtures and then the length from your last fixture to the transformer. Then add about 6-7″ per fixture for the connections. Intermetic recommends a 12 gauge cable 300 watts.


Now that you’ve got all of your materials, you’re ready to begin the actual installation. The first thing to do is to lay out cable & fixtures. Now we’re getting to the fun stuff. Place your fixtures on the ground where you want to install them. Then lay the cable around the entire area you are installing your fixtures. Provide a little extra cable (like a fist-sized loop) at each fixture. You need to do this so that there is enough cable available to connect your fixture to (see step 9).


Dig 2 – 3″ trench where you will actually lay the cable. Some people recommend more or less. I’ve seen as much as 5″ recommended and as little as 1′. I wouldn’t go any less than 18″, but to be sure you don’t pull up your cable doing landscape digging, it’s better to go a little deeper, but definitely no more than 3″.


Bury the cable lightly. At every fixture location, loop the cable up out of the dirt for connection to your fixtures.


Install the transformer and plug it in. Basically all you need to do is attach it to your house or a post next to your GFCI switch. Be sure to follow all of the directions that come with it to be sure it’s grounded properly. Once it’s installed and grounded, connect your cable to it by cutting the end of the cable with wire cutters and stripping off ½” of the insulation. Then place each of the 2 wires under the terminal screws and tighten the screws down on them. This is just like hooking up a stereo speaker.


Using your sledgehammer, punch your stakes (evenly spaced) into the ground holding each one as straight up and down as you can. Connect the light fixtures to the stakes and snap each fixture’s cable piercing fitting into cable. To do this, you put place tab of the cable snap on either side of the cable and fit them together through the cable.


Now just bury the cable where you made your connections, fill in the dirt completely and tamp it all down. And you’re done other than all that cleanup you most likely have to do.

Choosing a Transformer

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Transformers come in three types.

  • Manually operated – You turn the lights on and off by hand.
  • Automatic Timers – The lights turn off and on a set schedule.
  • Photocell-eye – These lights turn on at dusk and off at dawn.

Choosing a Power Source

Solar power or electrical power source.

  • Electrical power lighting will require a 120 volt weather proof outlet, i.e., you will need a GFCI outdoor outlet.
  • Solar power lights use stored solar energy to power the lights at night. Solar lights are ecologically friendly and can save you money.