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How to Install Under Cabinet Kitchen Lighting
Learn how to install low-voltage modular LED lighting under your kitchen cabinets.
Lighting is one of the most important aspects of your home, making it usable, safe, and inviting. It may also be one of the least planned and most under-appreciated facilities in your home--particularly in the kitchen. As a site for family gatherings and a work area for food preparation, school projects, crafts, and more, the kitchen needs good lighting. One way to enhance that lighting is to install LED lights under the kitchen cabinets for better visibility and ambiance. LED (Light Emitting Diode) lights are state-of-the-art. They are longer lived and five times more energy-efficient than the incandescent lights made commercially viable by Thomas Edison and others more than a century ago. The manufacturer of the fixtures we chose rates them for 60,000 operating hours--that's like burning them 10-plus hours every day for more than 15 years. They are also attractive, dimmable, low-profile and virtually invisible when mounted under the cabinets. Fixtures that use LED lights are easy to install and rated as low-voltage, typically powered by a transformer that steps down house current to 12 volts. In short, LED lighting is a very bright idea.
Step by Step Instructions with Video
Step
1
Select the LED Lights and Decide Where to Locate Them
Begin by researching which LED light fixtures are appropriate for your kitchen application, where you will install them, and which electrical outlet will power them. The fixtures chosen for our project require a transformer that steps down 120 volt house current to 12 volts. From the transformer, the light fixtures can be arrayed in a series with each successive light module plugging into the next light with a small pigtail provided by the light manufacturer. All lights energized by the single transformer will be controlled with a dimmer switch, so we decide to rewire an unused telephone jack site for the dimmer switch and hide the transformer inside the cabinet. Before you start, read the manufacturer's instructions for installation and wiring.
Step
2
Remove the Cover Plate from the Existing Phone Jack
Take the cover plate off the existing telephone jack.
Step
3
Back Out the Screws from the Jack Electrical Box
Back out the screws that hold the jack itself in place.
Step
4
Cut the Wires
Use insulated wire cutters to snip the wires off the unused jack.
Step
5
Remove the Telephone Jack Receptacle
Remove the telephone jack receptacle box entirely.
Step
6
Measure from the Wall Opening to the Door Casing
Measure and record the distance from the center of the wall opening where you removed the telephone jack to the edge of the casing beside the door. Our measurement was 26 1/2 inches.
Step
7
Mark That Distance Along the Baseboard Trim
Measure and mark 26 1/2 inches in the opposite direction from the door casing back along the wall just above the baseboard trim. This method lets us avoid the countertop that prevents us from measuring straight down the wall, and marks the spot for threading an electrical wire from the basement up through the opening in the wall in a later step.
Step
8
Remove the Shoe Molding
Remove the shoe molding at the bottom of the baseboard with a pry bar. Protect the baseboard by slipping a putty knife behind the molding next to the baseboard and pry against it.
Step
9
Bore a Hole Through the Floor
Bore a hole through the floor at an angle using a 1/4-inch drill bit with a long shaft on your power drill. It will exit at a point in the basement that is positioned below the kitchen cabinets.
Step
10
Leave the Bit in Place and Mark the Basement Ceiling
Leave the drill bit in place and go to the basement to locate it in the ceiling and mark the exit location.
Step
11
Remove the Drill Bit
Go back upstairs and back out the drill bit.
Step
12
Drill Through the Ceiling with a Bell-Hanger Bit
Use a larger 3/4-inch bell-hanger bit to drill through the ceiling in the basement upwards into the wall.
Step
13
Insert a Fish-tape Through the Hole
Insert the end of a stiff wire called a "fish-tape" through the hole and into the wall. If you have drilled at the correct location, the fish tape should come very close to the box opening where you removed the telephone jack. Continue pulling the fish tape through until just a small length is left at the basement end.
Step
14
Hook an Electrical Cable Over the Fish-tape
Hook an electrical cable to the end of the fish-tape on the basement side and wrap electrical tape tightly around this temporary connection to prevent it from separating inside the wall while you fish the tape and the wire through the hole.
Step
15
Draw the Fish-tape and Cable Through the Box Opening
Draw the fish tape and attached electrical cable through the box opening into the kitchen.
Step
16
Cut the Fish-tape and Cable Apart
Cut the tape and cable apart.
Step
17
Uncoil the Electrical Cable to an Electrical Junction Box
Return to the basement and uncoil enough cable to reach the nearest/most convenient electrical junction box with length to spare. Snip the cable.
Step
18
Drill Horizontal Holes Through the Floor Joists for the Cable
Use a right-angled drill and auger bit to bore a series of horizontal holes through the floor joists to run the cable across the ceiling from the wall to the junction box.
Step
19
Thread the Cable Through the Holes to the Junction Box
Thread the electrical cable through the holes until you reach the most convenient junction box. In our project, it is the junction box that runs to the garbage disposal.
Step
20
Remove the Cover on the Junction Box
Remove the cover on the junction box.
Step
21
Test the Junction Box with a Voltage Tester
Test the junction box with a voltage tester to confirm that it contains an active circuit.
Step
22
Switch Off the Current to the Junction Box at the Breaker
Ensure that the circuit that feeds 120 voltage to the junction box is switched off at the breaker in the circuit box. This level of voltage is potentially dangerous!
Step
23
Confirm the Electrical Current Is Off
Check again with the voltages tester to ensure that the circuit is no longer receiving electricity.
Step
24
Slit the Plastic Sheathing on the New Electrical Cable
Slit the plastic sheathing on the cable with a sharp utility knife, being care not to nick the insulated wires inside.
Step
25
Strip Off Several Inches of Sheathing
Strip off several inches of the sheathing.
Step
26
Remove 1 1/2-Inches of Insulation from the Wires in the Cable
Use wire strippers to remove the insulation from the wires inside. Leave about 1 1/2-inches of exposed copper wire.
Step
27
Insert a Wire Connector in the Existing Junction Box
Install a wire connector in the existing junction box, and finger tighten the lock not.
Step
28
Secure the Lock Nut on the Connector with a Screw Driver
Use a screw driver to snug the lock nut, pushing against the angular edge in a counter-clockwise to direction to secure it.
Step
29
Secure the Cable to the Junction Box
Pass the wires through the connector and tighten the screws on the connector clamps on the outside of the box to secure the cable to the box.
Step
30
Remove Wire Nuts from Wires in the Junction Box
Remove the wire nut from an existing wire in the junction box. The wire nut is a threaded and insulated solder-free cap that joins wires together. Match the wire color with the same color wire in the new cable, and twist them together. Color matching is critical. Repeat this process until you have color-matched and spliced the neutral/white, hot/black, and ground/green wires to the matching colored wires in the junction box. If you need additional advice on splicing the new wire to the junction box, check with your home improvement store for guidance on your specific wiring situation.
Step
31
Re-attach the Wire Nuts
Replace a wire nut over each of the three splices just made.
Step
32
Replace the Cover on the Junction Box
Replace the cover on the junction box. Do not restore electrical current to the junction box at this point.
Step
33
Drive in Cable Staples to Hold the Cable in Place
Drive in cable staples with a hammer to hold the full length of the cable in place against the joists. Be careful not to nick the insulation with the staple or the hammer.
Step
34
Drill a Hole in the Cabinet to Wire the Transformer
Go to the cupboard where the LED lighting transformer will be installed and use the bell-hanger bit to drill a hole through the vertical wooden backing into the wall behind.
Step
35
Pass the Fish-tape Through the Hole to the Outlet Opening
Pass the fish-tape downward through the hole to the box opening (where the telephone jack used to be) in the wall below. You will need to put your hand into the box opening to locate and grasp the fish tape once it gets within reach and then pull it through the opening.
Step
36
Hook a Length of BX Armored Cable to the Fish-tape
Hook the three wires inside a length of BX armored cable to the end of the fish tape and wrap them securely with electrical tape temporarily. For this run, we are using armored cable because non-metallic sheathed cable doesn't meet building codes for installation in cabinets.
Step
37
Pull the Fish-tape and Armored Cable into the Cabinet
Pull the fish tape and armored cable back through the box opening, upwards and through the hole in the back of the cabinet.
Step
38
Use a Cable Armor Stripper to Remove the Metal Jacket
Use a special cable armor stripper with a rotating wheel and crank to cut through the outer metal jacket on the armored wire.
Step
39
Expose the Three Wires Inside without Damaging Them
Pull off the excess armor to expose the three wires inside without damaging them.
Step
40
Slip the Wires in the Armored Cable into the Electrical Box
Slip the wires in the armored cable into an electrical box, pulling them to the bottom of the box to leave enough length to connect them later.
Step
41
Tighten the Connector to Clamp the Armored Cable
Use a screw driver to tighten the connector that clamps the outer metallic skin of the armored cable in place.
Step
42
Push the Non-Metallic Cable into the Box and Secure It
Push the non-metallic cable from the basement into the bottom of the electrical box and use a screw driver to tighten a similar but slightly different connector.
Step
43
Set the Electrical Box in the Opening and Clamp It to the Wall
Push the electrical box into the opening and tighten the screws to expand the ?wings? on the box and bring them in contact with the back side of the wall. The device clamps it to the front and back of the wall board. Unlike new construction, this box is not required to be attached to the wall framing.
Step
44
Strip Off 1 1/2-Inches of Insulation from the Six Wires
Strip about 1 1/2-inch of insulation off the ends of the wires to expose the copper beneath. Include the three wires from the non-metallic cable from the basement and three from the BX armored cable you pulled from the cabinet down to the electrical box.
Step
45
Twist Neutral/White Wires Together with Pliers and a Wire Nut
Twist the neutral/white wires together with a pair of pliers and secure them with a wire nut.
Step
46
Connect Black Wires on Dimmer Switch with Black Wires in Box
Connect the two black wires on the dimmer switch provided with the LED lighting fixture--twist one with the black wire from the basement and one to the black wire from the armored cable. Add wire nuts to both splices.
Step
47
Connect Green Wires Together and Secure with Wire Nut
Twist the two green ground wires together and secure them with a wire nut.
Step
48
Secure the Dimmer Switch in the Electrical Box
Set the dimmer switch in the electrical box and secure it by tightening the mounting screws.
Step
49
Position and Tighten the Cover Plate
Place the cover plate over the switch and electrical box and tighten the mounting screws.
Step
50
Tap the Knock-out Partition with a Hammer and Nail Set
Use a nail set and hammer to tap on the little "knock-out" partition/tab on the metal transformer box. It will probably remain attached by a small piece of metal.
Step
51
Twist Off the Tab with Pliers
Grasp the tab with a pair of pliers to twist it off and discard it.
Step
52
Insert an Armored Cable Connector in the Knock-out Hole
Insert an armored cable connector into the knock-out hole on the transformer box and finger- tighten the nut.
Step
53
Snug the Connector Nut
Use adjustable pliers to snug the connector nut.
Step
54
Slip the Armored Cable Wires into the Connector
Slip the wires from the cabinet end of the armored cable through the connector, tighten the set screw, and set the transformer in position against the wall.
Step
55
Strip Off Insulation and Connect Like-colored Wires
Connect the like-colored wires after stripping off about 1 1/2-inch of insulation. Twist white to white, black to black, and green to green and secure each color pair with a wire nut. Remember, color matching is critical to splicing electrical wire.
Step
56
Bore Holes in the Back Corners of the Cabinet Shelves
Bore 1/4-inch holes through the cabinet shelves to run the low voltage wires to the first row of lights. Position them close to the back corner so they don't interfere with other uses of the cabinets.
Step
57
Feed the Wire Downward Through the Holes
Feed the wire from the upper cabinet downward through the holes to the underside of the cabinet box.
Step
58
Start Plastic Cable Holders to Secure the Wires
Install plastic cable holders to secure the wires to the bottom of the cabinet without damaging the wire. Use pliers to grasp the small nail in each holder, position the device over the wire, and force the nail carefully into the wood.
Step
59
Finish Driving the Nails with a Hammer and Nail Set
Use a hammer and nail set to finish driving the nail into the bottom of the cabinet.
Step
60
Install Brackets Under the Cabinet for the Light Modules
Install the brackets to hold the light fixtures on the bottom of the cabinet. Secure them by driving screws through the bracket and into the cabinet with a power driver.
Step
61
Snap the Light Modules into the Brackets
Snap the first set of light fixture modules into the brackets.
Step
62
Plug the Low-voltage Wire in the First Light Module
Plug the low-voltage wire into the end of the fixture closest to the transformer.
Step
63
Connect the Remaining Fixtures with Pigtails
Connect the fixtures to one another with the short pigtails provided.
Step
64
Drill a Hole in the Top of the Cabinet for a Low Voltage Wire
Drill a hole in the top of the cabinet and push the wire from the transformer through to the top of the cabinet box.
Step
65
Run the Wire Above the Cabinets and Window Trim
Run the wire along the top of the cabinet, the trim above the window at the kitchen sink, and onto the adjacent set of wall cabinets.
Step
66
Bore Small Holes Through the Next Cabinets
Bore small holes through the top of the cabinet at the rear corner, through the corresponding corner of each shelf below, and finally through the bottom of the cabinet. These holes should align.
Step
67
Thread the Wire from the Top to the Bottom
Thread the wire from the top of the cabinet through each of the holes and out the bottom. You will need to add a plug to the wire to plug into the first light module.
Step
68
Secure Brackets for the Second Set of Light Modules
Secure the brackets for the second set of lighting modules, attaching them with screws.
Step
69
Snap in the Light Fixtures and Connect with Pigtails
Snap in the LED light fixtures and plug in the primary wire and the pigtails between each module.
Step
70
Position a Plastic Raceway Above the Window Trim
Use a plastic raceway to conceal the wiring that runs on top of the kitchen window. Peel off the protective coating from the self-adhesive on the bottom and press it into place.
Step
71
Push the Electrical Wiring into the Slot to Conceal It
Push the electrical wiring through the slot in the side to conceal it.
Step
72
Connect the Low Voltage Wires
Connect the low voltage wires that will carry power to the light fixtures to the low voltage output on the transformer. The manufacturer's instructions can offer you additional guidance. Go to the breaker box and flip the switch on the correct circuit to restore electrical current. The transformer will reduce the current from the potentially dangerous 120 volts to 12 volts.
