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Under Cabinet Light Bar Installation Guide


This guide is intended to be a helpful tool, containing useful tips and pointers to save you time, ensure your safety, and walk you through the 7 simple steps required for a seamless installation of your upcoming light bar project. If you have any questions during your installation, please feel free to contact our Customer Support team at 888-503-1317 or via e-mail at

Tools You’ll Need
Tape Measure Wire Stripper Screw Driver Power Drill (optional) Soldering iron and solder (optional)
Before You Begin

It is crucial to install any electrical product, including strip lights and their accessories, in accordance with the National Electric Code (NEC) and all other local building and electrical codes at the project location. If you are unfamiliar with the NEC or your local codes, we recommend hiring a licensed electrician to complete the installation for you.

Always consult your System Design and physical equipment to confirm that the voltage of your power supply and Under Cabinet Light Bars match.

This product is suitable for environments of ambient temperatures between -40°F to 122°F (-20°C to 50°C) and are intended to be installed indoors only.

Installation Instructions

Design Your System:

Under Cabinet Light Bars are a discrete way to illuminate the darkest corners of any kitchen. The installation should begin by considering the quantity of lights you’ll need, the various lengths needed, how the lights will be controlled, how the lights will be connected, where the power supply will be stored, and what light temperature is desired for the project.
While the wall plugs in most residential homes provide 120V AC power, aspectLED’s light bars operate on low voltage (24V DC) power. To operate, you will need a power supply to transform your home’s AC power to DC power.

The following equation will help determine which power supply is needed for your project.
Watts per fixture x How many fixtures are being installed = Z
Z x 1.25 = Minimum size of power supply needed

Also consider that our light bars come standard in seven different lengths (6”, 12”, 18”, 24”, 36” 42”) and three different LED light colors; 3000K Warm White, 4000K Cool White, and 6000K Day White. Make sure to select the right color, lengths, and quantities for your specific project needs.

Additionally, you’ll need to consider if the system will be wired in series or parallel. If wired in parallel, you’ll need light bars with wire leads on a single end. If wired in series, you’ll want the wires on both ends. Depending on your specific system design and layout, you could also use a combination of the two approaches.

How you’re planning to control the lights is another major decision to be made early in the planning stages. Your preference for a standard wall switch, remote control, or app control will impact your system’s layout, as well as the other accessory products you’ll need for basic functioning.
Use the wiring diagrams in the below drop down to aid your system design and product selection. Now that you know how your system is designed and what equipment is needed to operate it, it’s time to figure out where you’ll be installing your system accessories and electrical wiring.

Locate Your System Accessories:

Most LED power supplies, controllers, and accessories are not in-wall rated and may require servicing in their lifetimes. Because of this, you should always install your system accessories in accessible locations. Common storage locations include closets, utility storage areas, cabinets, attics, or basements - anywhere the physical equipment is within reach.
When choosing your location(s), keep in mind that you’ll likely be running electrical wires between multiple light bars and your other system components. AC line access, material obstructions, physical distances/voltage drop, and visibility of wiring should be considered at this step.

Additionally, the specific details about the power supply (dimmable v. non-dimmable) and control type (switch v. remote v. app) chosen for your system will also dictate where the equipment can and should be installed.

Dimmable power supplies are usually installed between the controls and the light bars. Whereas non-dimmable power supplies are installed between the AC line access and the controls.

Locate Your Light Bars & Wire Runs:

Start by laying out your light bars below the cabinets where they will be installed.
Next, cut any extra lengths of extension wire you will need for long gaps between each light bar length.
Then run the wire from your light bar run(s) to your controls and power supplies, trim the wire to final lengths, and strip the wire end. If needed, you can use a drill to run your wire from one location to another.

Finally, choose a connection method below to connect your system components and bring your system to light.
Make sure to consult a Voltage Drop & Wire Sizing Chart to determine the proper gauge required for any extra distances you need to run between your light bars.

IMPORTANT! Using the incorrect wire size will damage your products!
IMPORTANT! If installing wiring in a wall or ceiling, always use in-wall rated wiring.

Connecting your Under Cabinet Light Bars, Controllers and other Accessories:

Before making any connections, always double check that the polarity is correct by matching the red (+) and black (-) wires or strip connections. Incorrectly wiring the product will cause damage and void product warranties.

Light bar systems can be wired and connected by the following methods:

    Splicing low voltage wires
  • Wire nuts
  • Lever Nuts like WAGO Splicing Connectors
  • Mini Low Voltage Terminal Junction Box

After choosing your preferred connection method, connect all your system components EXCEPT for the Power Supply. We’ll take care of that in the next step.

Connecting to your Power Supply and Powering On:

After confirming that the voltage of your power supplies and light bars match, connect the positive (+) and negative (-) output wires from the power supply to the wire leads on the light bar or controller.

Double check all connections, then turn on the power to your circuit.
If you experience issues, see the trouble shooting guide below or contact our Customer Support team at 888-503-1317 or via e-mail at

Mounting Under Cabinet Light Bars, Wiring & Accessories:

Now that everything is connected and working properly, it’s time to mount your light bars and system accessories.

Under Cabinet Light Bars are typically installed centered left-to-right and closer to the front edge of the cabinet. This positioning will provide uniform light on the below counter or surface. Light bars arrive with 2-5 mounting clips to support the fixture. We recommend using a #4 ½” screw along with the mounting clips if installing light bars under wooden cabinets.

Most power supplies and controllers are designed to be mounted out of the way using mounting screws included in their packaging. Finally, you’ll want to conceal any exposed wiring using conduit or cable raceways.

All Done! Congratulations!

You’ve successfully completed the installation process. Now you can take a moment to sit down and enjoy your favorite beverage while giving yourself a pat on the back for a job well done.

Wiring Diagrams

AC Dimming = Dimmable Driver System [wiring diagram] (in wall dimmer switch + Dimmable PS + Strip = AC dimming

IMPORTANT! Dimmable power supplies should have a load of 60-80% of the total wattage. Loading the power supply within this range will allow for great dimming capabilities between dimmer switch and driver.

DC Dimming = 12V-24V Dimmable System [wiring diagram] (Non-Dimmable PS + handheld remote controller or Casambi + Strip)

LED CONTROLLERRGBWLIGHT BARSPOWER INPUTSIGNAL OUTPUTV+CH1: (red) V-: V-:::CH2: (green) V-: V-:::CH3: (blue) V-: V-:::CH4: (white) V-: V-:::V+V- POWER SUPPLYLED CONTROLLERCCT LIGHT BARSPOWER INPUTSIGNAL OUTPUTV+CH1: (red) V-: V-:::CH2: (green) V-: V-:::CH3: (blue) V-: V-:::CH4: (white) V-: V-:::V+V- POWER SUPPLYLED CONTROLLERPOWER INPUTSIGNAL OUTPUTV+CH1: (red) V-: V-:::CH2: (green) V-: V-:::CH3: (blue) V-: V-:::CH4: (white) V-: V-:::V+V- POWER SUPPLYWarm white = Red Channel (Ch 1) or Blue Channel (Ch 3)Cool White = Green Channel (Ch 2 ) or White Channel (Ch 4)If using Casambi controller, only use Ch1 and Ch2V- from strip can connect to any channel. If using multiple strips you can split them between all the channels if needed.12V-24V Dimmable System LED LIGHT BARSPlug-in adaptor system POWER SUPPLY120VAC12V or 24VV-V+ LED LIGHT BARSDimmable Driver System – for single color light bars only! POWER SUPPLY12V or 24V120VAC120VACV-V+GNDIMMER SWITCHGL
Trouble Shooting
Shift in brightness and/or temperature Make sure you did not exceed the maximum series run limit. This will cause excess voltage drop, resulting in decreased brightness and/or temperature as the run is extended.
Lights do not illuminate
  • Determine if power supply is connected to live power with a multimeter. If using an outlet plug another device, such as a nightlight, lamp or radio to verify it has power.
  • Confirm voltage types of both lights and the power supply are the same.
  • Verify wiring is correct and connections are solid between power supply and the lights. Check any solder points or connectors for loose connections.
Some lights are not functional Ensure all connections have been attached properly. Make sure that the strips have not been bent excessively, which may cause components and solder to detach from the circuit board.
Lights are flickering
  1. Check for loose connections and that strip light connectors are attached correctly. Strips vary in width so it is important that compatible models are used and consistent polarity is maintained.
  2. Check dimmable power supply and dimmer switch are compatible by checking our compatibility chart or by contacting our LED experts at 888-503-1317.
  3. Check that a compatible driver is installed. Ensure controller is not on dynamic mode. Verify that +/- connections of DMX systems are not reversed.
Lights are turning on/off repeatedly Ensure the driver is not overloaded. An overloaded driver will trip the internal auto-reset repeatedly, turning the system on/off. Check the voltage type the power supply is outputting with a multimeter.
Make sure that you are using a power supply that is outputting either 12 or 24 VDC that matches your strips. Many outdoor landscape transformers output 12VAC which is not compatible with our strips and will cause this behavior when used.
Installation trips main breaker Check wiring for a short circuit. If breaker continues to trip, there might be a short in your circuit. Call us at (888) 503-1317 option 3 or email us at to troubleshoot further.

More product resources and helpful tips on YouTube.