How to Install Deck Light Transformers

A deck.
  • 2 hours
  • Intermediate
  • 25-50
What You'll Need
Low voltage transformer
Wire strippers
Insulated staples

Deck lights need to be installed through a transformer in order for them to receive power. A low voltage transformer will be idle for lights because they plug into a wall socket unlike other household power supplies. If you already have completed the wiring for your deck lights, then the only steps left is to install the transformer so your lights will be complete.

    Step 1 - Select the Transformer for You

    When you are selecting the transformer you will want to have a low voltage to power your lights on the deck. The low volt transformer will convert its power of 120 volts into 12 volts that will be useful for having the unit outside.

    Step 2 - Correct Wattage for Transformer

    When you have found the type of style you want of either a timer or photocell you will need to determine how much wattage you will need for your transformer by adding up all of the deck lights you will be using. If you have 8 step lights at around 12 watts, you also are going to be adding an additional floodlight at 20 watts, then the total wattage will be 116 watts.

    Step 3 - Place the Transformer

    You want either a timer or photocell to install it by a receptacle. You should measure out how far the wires from the lights will reach to have enough room to reach the transformer and receptacle. If you do not have a receptacle you will have to install one in order for your transformer to have power for the deck lights.

    Step 4 - Circuit Cables to Transformer

    With many different lights, you should combine the wires into one single circuit cable. When you are connecting the wires you will also need to know the size of wire for the correct distance of the cable. The size of a wire of a 12 gauge should equal up between 0 to 50 feet. A 10 gauge wire should be between 50 and 100 feet and 8 gauge wire should be 100 feet or more. Now that you know the correct size of the wire and the correct distance, you will need to hide the cables by putting them under the deck or you can staple them by the stairs or somewhere not as noticeable.

    Step 5 - Install Transformer

    To install the transformer you will need to follow the direction on your manufactures installation guide. Most of the transformer you buy will need to be mounted by drilling in screws into the side of the wall where you will hang the unit. Now connect one of the wires into the label called A and the other wire into the B label. Other models will have different names like 12v for one wire and Common for the other wire. After this is done, you will want to connect the power cord to the receptacle to allow power to the transformer.