LED Strips: Installing, repairing, and replacing them safely

Learn everything you need to know about LED strips

In this new article, we answer many questions received from homeowners in San Antonio about LED strips, how they work and don’t work, how to choose them, how to install them, and so much more. If you have questions not answered here, please feel free to use the contact form on our site to ask us for answers. You can also communicate with us directly on our Facebook page.

Can you just cut LED strips?

Only cut the strips at the designated cut points to ensure they function correctly. One of the most common errors we see homeowners doing when they install these strips, is to cut them in the wrong areas of the strip, damaging the circuitry. Once damaged, the strip becomes unusable.

Where is the best place to cut LED strips?

The only place to cut your strips is at the designated cut points, between 2 copper dots. The cut points are marked with a line or scissor icon. In low quality strips, this mark may be missing. Also, when you purchase strips, look on the package if they are cuttable. It will be indicated. If not, don’t buy them.

How many times can you cut LED light strips?

It depends on the number of cut points available on the strip. Typically, you will find cut lines every inch or two. The more LED per unit of length, the smaller you can cut the strips.

Can you use the rest of a LED strip after cutting it?

Yes, you can use the remaining part of the LED strip after cutting it, provided you have the necessary connectors and power supply to operate it (and also provided you didn’t cut it at the wrong place).

What is a controller for RGB or smart LED strips?

A controller enables you to change the color, brightness, or pattern of RGB (Red-Green-Blue) LED strips. It can be a simple handheld remote unit or a wall-mounted unit. You can also pair smart strips with a dedicated smartphone app.

Can you add a dimmer to an LED strip?

Yes, as long as it is LED-compatible. it must be installed between the power supply and the strip. Dimmers are a practical way to create layers of lighting intensity in a room and to give more depth to your living space.

Do LED strips come with mounting clips or brackets?

Not often. But you can buy them separately. They help secure the strip in place. Use clips if the adhesive backing on the strip isn’t sticking to the supporting surface (e.g., texture issue), or if you need to add a bit of space between the supporting surface and the strip to help with heat dissipation (in tightly packed areas, for instance).

What happens if you cut a strip in the middle?

If you cut an LED strip anywhere else than on the designated cut points, you will damage the circuitry and prevent that section of the strip from working.

If you risk damaging your strip or cut at the wrong place and create a fire hazard, it is safer and probably also cheaper to get a professional electrician like All Star Electric to install your strips and LED lighting system.

Can you cut L.E.D. string lights to make them shorter?

The keyword here is “string lights”. Not strip lights. Unlike strips, most string lights aren’t designed to be cut. Cutting them can damage their circuitry and render them unusable.

Can you feed power to a LED strip from both ends?

Yes, feeding power from both ends can help maintain consistent brightness across long strips, especially if there is a noticeable voltage drop towards the end of a strip. As electrical current travels through the conductive material of the LED strip, it encounters resistance. This resistance decreases the light intensity of the strip.

Why are my LED strips not as bright at the end?

This is likely due to a voltage drop, a common phenomenon in longer LED strips. 

Can a strip be powered from the middle?

Indeed, LED strips can be powered from the middle, especially to maintain consistent brightness across a long strip.

Can I connect 2 strips to one power source?

Yes, two or more strips can be connected to a single power source, but the power supply must be able to handle the combined current draw of all connected strips.

What is the typical current draw range for an LED strip?

The current draw of a strip varies based on several factors:

1. Type of LED: Different LEDs, like SMD 3528, SMD 5050, or SMD 2835, have different current requirements.
2. Density: The number of LEDs per meter or foot. A strip with more LEDs per meter will draw more current.
3. Color: Different colors can have different current requirements. For instance, white or blue LEDs might draw more current than red or green LEDs.
4. Brightness: Some strips are adjustable. More brightness = more current.

Typically, for common strips like the SMD 5050, the current draw might be around 20mA per LED. So, if you have a strip with 60 LEDs per meter, it would draw around 1.2A per meter (60 LEDs x 20mA = 1200mA = 1.2A).

How to determine the current draw of a L.E.D. strip?

To determine the current draw of a strip:

1. Check the packaging or product label: Most of the times, the manufacturer will provide specifications on the packaging or directly on the reel of the strip. Look for a current rating in amperes (A) or milliamperes (mA).
2. Refer to the product manual: If the strip came with a manual, it might contain detailed specifications, including the current draw.
3. Visit the manufacturer’s website: If you know the brand or model of the strip, the manufacturer’s website might have detailed specifications. Sometimes, distributors do a better job at publishing relevant information than the manufacturers themselves. No disrespect meant, but the local distributors (wholesalers) of Chinese manufacturers usually do a more thorough job at providing the technical specifications of an electrical product because Customs and certification agencies require them.
4. Measure with a multimeter: If you have a multimeter, you can measure the current draw directly. Set the multimeter to measure current (in the appropriate range), interrupt the positive power lead to the strip, and connect the multimeter in series. Ensure the LED strip is fully powered on during this test.

Why should you check the current draw of the L.E.D. strip when you buy it?

For several reasons:

1. Power supply selection: Your power supply must be able to provide the total current required by your strip. If you are connecting multiple strips, add up the current draw of each strip and select a power supply that handles the combined total after you multiply it by 1.2x for safety.
2. Safety: Overloading a power supply can lead to overheating and potential fire hazards.
3. Performance: If your LED strip receives the correct current, it will emit an optimal brightness and will last longer.

How many volts can LED strips handle?

The voltage an LED strip can handle depends on its design. Common voltages are 5V, 12V, and 24V.

Can you power a LED strip with a battery?

Yes, batteries can power LED strips. The image on the left shows an example of a LED strip powered by a battery.

Why are there 3 pins on the plug of an LED strip?

The three pins typically correspond to the positive, negative, and data or control signal for RGB LED strips. Single-color strips don’t use the third pin.

Do all LED strips use the same amount of power per unit of time? Why?

No, the power consumption of LED strips varies based on factors like the type of LED, the number of LEDs per meter, and the voltage and current ratings of the strip. Additionally, the color(s) of a strip will impact its power usage.

Which colors in LED strip consume the most and the least power?

The power consumption of an LED varies according (in part) to its color.

• Red LEDs: These often have the lowest forward voltage, typically around 1.8 to 2.2 volts. As a result, they might consume less power than other colors when driven at the same current.
• Green LEDs: These usually have a forward voltage in the range of 2.8 to 3.4 volts.
• Blue and White LEDs: Both blue and white LEDs (white LEDs are often blue LEDs with a phosphor coating) typically have the highest forward voltage, often between 3.0 to 3.4 volts. Consequently, they might draw more power than red or green LEDs under the same conditions.

Which colors in LED strip use the least amount of power?

Generally, red LEDs consume less power compared to green or blue LEDs. However, actual power consumption can vary based on the design and manufacturer.

Can I join two or more LED strips together?

Yes, LED strips can be joined using clip-on connectors or by soldering, depending on the type of strip and your expertise.

How many LED strips can you connect together?

The number of LED strips you can connect together depends on the capacity of the power supply and the total current draw of the combined strips. Always ensure the total current draw doesn’t exceed the rating of the power supply.

What to do with the ends of a LED strip?

The end of an LED strip can be sealed with endcaps to prevent dust and moisture ingress. If you plan to re-use the cut end, you can attach a connector for future extensions. Choose an IP67 rating for good waterproofing.

Can LED strips be a fire hazard?

LED strips are much cooler than incandescent bulbs. But overheating occurs with poor quality LEDs and incorrect power supplies. Improper installations can create potential fire hazards. The quality of the product and the quality of workmanship at installation impact the safety of your system.

Is it safe to install LED strips under a bed?

Yes, it is safe to install LED strips under a bed for ambient lighting, provided that the installation is done correctly and the strips don’t overheat.

Is it safe to touch a LED strip?

Yes, LED strips are safe to touch when powered on, as they don’t generate a lot of heat. However, avoid touching any exposed wiring or connectors. These components heat up (even if slightly) and the heat needs to dissipate.

Is LED lighting explosion-proof?

LED fixtures rated as explosion-proof fall under Classifications C1D1 and C1D2. They also show an IP rating of at least IP54. These LED fixtures to be explosion-proof for use in hazardous environments. These fixtures have robust casings and are certified for such use. They are a bit of an “overkill” in a home environment.

What happens if you put too much power into an LED?

Overpowering an LED causes it to overheat. This reduces its lifespan and cause it to burn out. All Star Electric San Antonio always use the power supply recommended by the manufacturer.

Is it safe to install LED strips outside as Christmas decorations? Why?

Yes, it is safe to use LED strips as outdoor Christmas decorations, provided their rating is for outdoor use (e.g., they must have a suitable IP rating). 

Which types of LED strips will run the hottest?

High-density LED strips with more LEDs per meter and high-power LEDs tend to run hotter than other types. These strips must be installed so that heat dissipation happens. It is not advisable to install them in confined, non-ventilated spaces. Consult with a licensed electrician like All Star Electrical San Antonio.

Can you safely install LED strips in an attic where blown-in insulation material is present?

LED strips produce less heat than traditional bulbs BUT they MUST receive proper ventilation and can’t be covered by insulation which can trap heat. Always check the manufacturer’s guidelines for installation recommendations. Consult with San Antonio licensed electrician All Star Electrical to understand the requirements and the risks. Call us at (210) 391-0274.

What if you plug an LED strip into the AC mains?

Plugging an LED strip directly into AC mains without an appropriate driver or transformer will damage the strip because most LED strips operate on low-voltage DC.

What causes LED strips to stop working?

There are various reasons to LED stopping to work: damaged LEDs, broken circuitry, power supply issues, faulty connectors…

What causes LED lights to explode?

While rare, LED lights can “explode” or burst due to manufacturing defects, overheating, power surges, or using incorrect power supplies.

What causes LED strip lights to flash?

LED strip lights can flash due to power supply issues, faulty LEDs, or incompatible dimmer switches. 

Dimming LED strips is more complex than dimming traditional incandescent bulbs due to the differences in their electrical characteristics.

Why is blue the “most difficult LED color”?

Blue LEDs require a higher voltage to operate. Their composition includes more complex semiconductor materials than red or green LEDs. Blue LEDs also tend to have a shorter lifespan and are more sensitive to temperature variations.

Which are the 3 brightest LED strip colors?

The perceived brightness can vary, but research generally rates white, blue, and green the brightest LED strip colors.

Can LED strips favor a deeper, more relaxing sleep? If so, which colors and what color range (in Kelvin)?

Warm-colored LED strips, especially those in the red to orange spectrum (around 2000K to 3000K), can promote relaxation and potentially aid sleep. Blue light, on the other hand, can suppress melatonin production and disrupt sleep.

About All Star Electric San Antonio

As professional electricians in San Antonio, All Star Electric San Antonio installs, repairs, and inspects all types of electrical systems, both in home, offices and retail spaces. With the advent of LED technologies, lighting systems can now “sculpt” the atmosphere of a home indoors and outdoors. In office and retail setting, LEDs increase productivity, serve to highlight products, and render color more truthfully than incandescent bulbs and neon lights. 

We have been in business in San Antonio almost 30 years, and we serve the whole San Antonio community and neighboring cities such as Helotes, Selma, Castle Hills and Alamo Heights. We keep an A+ rating at the BBB San Antonio.