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Rail Light Installation Instructions


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Before you begin

Place the transformer in its anticipated location without connecting it to the power source.


New Decks: If you’re doing light and handrail installation simultaneously, prepare the underside of the railing by cutting a space for the wire. The groove should be sized to the gauge of wire, creating a snug fit. This will reduce the chances of hitting it with a screw later.


Existing Decks: If you’re installing lights on an existing deck and handrail, you’ll run the wire underneath the handrail and staple it every 4-6 inches with stainless steel staples.


Design note: Rail lights are often available in styles matching lit and unlit post caps. It’s easy to install both at the same time – all you have to decide is the style you prefer. For help at any time, call the DecksDirect PowerLine at 1-888-824-5316, 7a.m. to 5:30p.m. Monday through Friday, CST. Callbacks can also be provided afterhours and on weekends.



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Step 1

Looking down on the post, mark the center with an "X" by drawing two lines from corner to corner.



Step 2

With a 1-1/2" - 2" Forstner bit, drill a hole slightly deeper than the incoming wire level. After drilling holes in each post, go back and use a shop vac to clear away as many wood particles as possible.





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Step 3


Using the 1/2" drill bit, create a hole from the side of the handrail post into the core of the deck post. If you're creating a chain of lights, you may need to create holes in both sides of the post.











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Step 4


Determine the desired height for your rail lighting – ideally, it will be level or just below the hand railing. Using a tape measure, mark the location in the center of each post.

Drill wire hole for the rail lights. Position a 1/2" drill bit on the spot marking the location of the rail lighting, and drill at an angle to the pocket in the center of the post.

If the rail light is too far below the post hole, a second hole down from the pocket may be needed.





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Step 5

Run the appropriate gauge of wire from the transformer to the first post and rail light, leaving a loop of extra wire at the top of each lit post and at the location of each rail light.


New Decks: Run your wire from post to post in the railing groove you created before starting. Do not install the top rail until after the lighting system has been tested and verified to work!


Existing Decks: Loosely run the wire along posts and underside railings, threading them up and creating a loop in each deck post. Do not secure any of the wire with staples at this point.





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Step 6


Cut back any excess wire and leave enough exposed to make connections without creating excess bulk. Separate each wire pair into 2-3" single strands. Using wire strippers, remove approximately 5/8" of sheathing from each wire – including the wires on the light fixture.











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Step 7


Stay consistent in matching wire types as you continue through the wiring process. Most wires will have a "smooth" black wire combined with another wire that has white lettering – matching polarity is especially critical for LED lights.

Taking one wire from each light fixture and its counterpart from the wire threaded into the post, hold the two wires together with the ends even. Twist a waterproof wire nut onto them, pushing firmly until hand-tight. DO NOT over torque. Repeat for the second set of wires. Wipe away any excess silicone sealant in and around conductors, and then wrap the connections with electrical tape to prevent accidental dislodging.







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Step 8


Tuck the wire and wire nuts into the recessed hole on top of the post, placing the cap and rail lights in position. DO NOT secure the post cap, rail light, handrail or wiring until you have tested the entire lighting system.













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Step 9


ALWAYS READ AND FOLLOW THE INSTRUCTIONS THAT COME PACKAGED WITH YOUR TRANSFORMER BEFORE INSTALLATION. Locate and remove a perforated knockout circle in the bottom or side of the transformer to run the wires through. Secure the transformer in the desired location using the mounting brackets found on the transformer. If the transformer has a built-in photo eye, make sure it’s exposed to direct or indirect sunlight.






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Step 10


Separate eachwire pair into 2-3 inch single strands. Using wire strippers, remove approximately ¾" of sheathing from each wire. Secure one side to the common connection point and the other side to the 12v connection point on the connection terminal of the transformer. For transformers that do not have connection terminals, waterproof wire nuts will be needed for your connections.


Tip – When connecting the wires in a “loop” configuration, polarity/consistency of the wires must be maintained.





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Step 11


If the transformer has an on/off switch, verify the switch is in the "OFF" position before plugging the transformer into a timer or directly into a GFCI outlet. After connection to an outlet, turn the transformer switch to the "ON" position


Tip – If the transformer has a photo eye built into the transformer, place a piece of tape over the photo eye for testing a low voltage system during daylight hours. It may take 2-5 minutes for the photo eye to respond after covering.





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Step 12

Finish the wire installation. Having verified that the light system works, unplug the power source to the transformer.


New decks: Secure the handrail’s top board, any other finishing boards and post caps. Take care not to hit any wires with screws.


Existing decks: Secure the wiring along the posts and under the handrails by using the staple gun. Be sure to center the staple directly over the wires and DO NOT staple through the wire. If you accidentally staple the wire, simply remove the staple and re-apply a new one.


Depending on the post cap and rail lighting fixtures, attach them with the finishing screws provided, or slide into place. Clear silicone caulk works great for securing post caps that don't have mounting screws.

Plug in the transformer and turn its power switch to "ON". Enjoy your illuminating deck experience!


For troubleshooting, see Frequently Asked Questions.

Download Full Lighting Guide  

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3900 50th Ave N #100 Minneapolis, MN 55429
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