Renovation guides

How to install low-voltage path and string lights yourself: step by step

Plug-in low-voltage lights, solar lights and string lights are safe DIY: the transformer steps the power down, and the only line-voltage part is an outdoor outlet that already exists.

Difficulty 2 of 5 · 1 weekends · you can do this

Photo of your room, the look you pick, then this guide with the materials counted for your room.

Step by step

1. Step 1 of 12

   Plan where the light goes

   

   Walk the yard at dusk. Mark path lights along walks and steps, a light or two at plants or the fence, and where string lights will hang. Sketch the cable route from the outlet to every fixture.

2. Step 2 of 12

   Add up the watts and size the transformer

   

   Add the watts of every low-voltage fixture. Pick a transformer rated above that total with the headroom its label asks for, with a timer or a photocell.

3. Step 3 of 12

   Check the outdoor outlet

   

   Press TEST on the GFCI outlet (or the GFCI breaker that protects it): the power must cut off. Press RESET: it comes back. The outlet needs an in-use cover — one that closes with a cord plugged in.

   Before you plug anything in

   • The outdoor outlet is GFCI-protected: TEST cuts the power, RESET brings it back
   • It has a weatherproof in-use cover that closes with a cord plugged in
   • No new outlet, circuit or switch is needed — otherwise an electrician does that part first

4. Step 4 of 12

   Mount the transformer

   

   Mount it on the wall or a post next to the outlet, at the height its manual gives, and plug it in only at the end.

5. Step 5 of 12

   Lay out the fixtures and the cable

   

   Set the fixtures on the ground where they will go and lay the cable along the route, with a little slack at each fixture.

6. Step 6 of 12

   Connect the fixtures

   

   Connect each fixture to the cable with the connectors that come with it or waterproof landscape connectors. Strip and attach the cable to the transformer's low-voltage terminals as its manual shows.

7. Step 7 of 12

   Test at dusk

   

   Plug in and switch on. Check every light works and, with the multimeter, measure the volts at the last fixture on each run: it must be inside the range the fixture's box gives. Low at the end: move the cable to a higher-voltage tap if the transformer has one, or shorten the run.

8. Step 8 of 12

   Before you bury the cable

   

   Unplug the transformer. Check the route one last time against the 811 marks.

   Before you dig the trench

   • 811 marks are in and the trench does not cross a marked or private line
   • The buried cable is low-voltage from the transformer — never a 120 V extension cord
   • Every light passed the test

9. Step 9 of 12

   Bury the cable 6 in

   

   Push the flat spade in and rock it to open a slit about 6 in deep (or as deep as the fixture maker says), tuck the cable in, and step the slit closed.

10. Step 10 of 12

    Mount the hooks or the guide wire

    

    Screw hooks into solid wood — a post, the fascia, a fence post — about every 10 ft along the run. For long spans, stretch a guide wire between anchors and tighten it with the turnbuckles.

11. Step 11 of 12

    Hang the string lights

    

    Hang outdoor-rated strings from the hooks or clip them to the guide wire. Link no more strings end to end than the box allows. Leave a drip loop — a dip in the cord — just before the plug so water drips off before it reaches the outlet.

12. Step 12 of 12

    Set the timer and tidy up

    

    Set the timer or photocell, close the in-use cover, and tuck any loose cable out of the way of feet and mowers.

Draft guide written from standard practice, not yet reviewed by a licensed pro. Follow product labels where they differ.

Español