Installing Outdoor Low Voltage Lighting Systems

Low voltage lighting is a great outdoor home improvement project that is safe and easy to do for the average home owner.

If you already have a 110 volt power outlet outside you just need to plug in the low voltage transformer and run the cabling.

If you don't have an outdoor outlet you can hire an electrician to install one and then the hard part of wiring the lighting system is done.

Power Requirements

Low voltage lighting runs on 12 volts and requires a transformer to reduce normal household electricity (from 110/120 volts). You must have a 110/120 volt power outlet available, either outdoors or indoors. Get a professional electrician to install one for you if necessary.

Transformer Requirements

When choosing the transformer, you need to allow for some power loss in the wiring (voltage drop). Add up the wattage of all the fixtures in your lighting design to determine the total wattage. If the total wattage is close to a transformer’s wattage, choose a higher capacity transformer. For example, if the total is 64 Watts of lights, choose an 88 Watt transformer rather than a 66 Watt transformer. Another reason to choose a higher capacity transformer is to give yourself some flexibility should you decide to expand or change your lighting scheme in the future.

Some other features to consider are the transformer rating, built-in photocell, increment timer for on/off, and multiple on/off timer.

*If you are using an transformer indoors (to avoid theft, etc.), make sure it is rated for indoor use and that it is installed with at least 3 inches of space around it.

Wire Requirements

Make sure you use 12 volt outdoor lighting wire that is rated for outdoor use. 12 gauge 2 connector wiring is often used. Pre-measure the wiring runs and order a bit extra. Add an additional 10% to the order just in case.

Light Fixture Requirements

Make sure you review your project and choose lights that suit the purpose you have in mind. You can now find outdoor lights on the Internet available for almost any project. If you choose lights from the same manufacturer, you should be able to mix a variety of different styles of low voltage lighting on one transformer but make sure you consider the Wattage rating on the different lights because they can vary.

Installation

Once you have a plan for your low voltage lighting design, installing the fixtures and cabling is straightforward.

Lay out the fixtures in the correct positions and distances from the transformer and other fixtures. Pay attention to spacing.
- space path lights 8 to 12 feet apart
- position the first fixture at least 10 feet from the transformer
- don't place a light less than 10 feet from a pool or fountain
Lay the cable above ground next to the fixtures according the cable runs in the design.
If there is grass along the cabling run, lift the sod.
Make a 3-inch trench.
Bury the wire in the trench, leaving ample slack at both ends of the cabling run and at each light fixture.
Attach a T-connector in the middle of the cabling run and lay the cable back to the outdoor power outlet.
Attach the cable to the two terminal screws on the transformer. You'll have to strip the wire 1/2".
Drive a wooden post into the ground next to the power outlet and attach the transformer to the post.
Plug the transformer into the power outlet.
Connect the fixtures to the cable. Most low voltage kits have quick connectors that make this step easy. The bulbs should light up. Test the lights at night to make sure you are happy with the look. Adjust the lights and wiring runs before finishing the installation.
Position and mount the fixtures as per manufacturer instructions.
Replace the sod, tucking extra cable and connectors out of sight.