A landscape transformer powers low-voltage outdoor lighting. Landscape transformers reduce voltage from 120 volts to 12 to 22 volts, reducing the safety hazard of power cords outdoors. Approximately 15 feet of cable can run per transformer to various lighting systems outside. Troubleshooting the landscape transformer is necessary if the outdoor lighting is not working.
Disconnect the landscape transformer from the electrical outlet before performing any troubleshooting steps.
Bring the main cable and light connector up to no more than 6 inches underground if the transformer is not working. Keep the transformer cable and connector at a depth no more than 4 inches below ground if placing the cables under potentially flammable material such as wood chips or leaves and no more than 6 inches underneath all other surfaces.
Add up the individual wattage of each fixture that is attached to the landscape transformer. Determine the total output of the transformer by looking at the transformer power label, which is typically about 600 watts. Do not exceed the total output of the landscape transformer from the individual fixtures. Add a second landscape transformer if necessary.
Use 12-gauge cable for most installations when the combined wattage of fixtures is between 150 and 300 watts if there is a voltage drop in the cable run. Note that runs exceeding 200 feet cause a voltage drop. Use two output cables. Connecting one cable to the “HI” terminal block for the longer distance and the other cable to the “LOW” terminal block for the shorter fixture distance increases wattage to the fixtures located farther away from the landscape transformer.
Test the photocell during the day if you are not sure that the transformer is working correctly at night. Plug the transformer into a 120-volt GFCI outlet. Set the black cover over the photocell ensuring no light reaches the photocell, and then set the transformer’s mode to “Auto.” Once the photocell is completely in the dark, the outdoor lights should illuminate. Removing the plastic cover turns off the lights. Replace the photocell if necessary by unplugging the transformer and removing the power pack. Loosen the screws on the access hatch and then on each terminal allowing access to the photocell wire. Remove the wire retaining clip, and then slide open the clip hatch and remove the photocell wire. Slide the wire out through the square hole to remove the photocell. Place the new photocell wire into the square hole and reverse the process to finish the installation.