Selecting the appropriate power supply is crucial to the success of your LED lighting project. The right power supply ensures your LED strips or modules operate performantly and have a long lifespan. This guide will help you understand how to choose

<p>Selecting the appropriate power supply is crucial to the success of your LED lighting project. The right power supply ensures your LED strips or modules operate performantly and have a long lifespan. This guide will help you understand how to choose a power supply that matches the needs of your installation.</p><p>If you just want quick and easy way filter our offerings down to a selection of suitable options, try our <a href="https://www.wired4signsusa.com/pages/tools/led-driver-recommender" target="_blank" rel="noopener noreferrer">driver recommender</a>.</p><p>Note: This guide deals with typical, &quot;constant voltage&quot; LED strips and constant voltage power supplies. If you require a constant current supply or are unsure, please contact us for guidance.</p><h2 id="calculating-your-power-requirements">Calculating your power requirements</h2><p>To determine what wattage power supply you need, you will need to calculate the total power consumption of your installation.</p><p>This is pretty similar between strips and modules, but we&apos;ve detailed the steps for both to make it simpler.</p><p>Note that the calculator in our <a href="https://www.wired4signsusa.com/pages/tools/led-driver-recommender" target="_blank" rel="noopener noreferrer" id="isPasted">driver recommender tool</a> can be used for these calculations, even if you don&apos;t use the recommendations.</p><h3 id="calculating-led-strip-power-consumption">Calculating LED strip power consumption</h3><p>To calculate the total power consumption of your LED strip:</p><ul><li>Find the power consumption of your LED strip. On our site, this is listed in watts per meter in the &apos;General specifications&apos; section of the description on the product page.</li><li>Multiply the power consumption by the total length in meters of LED strip you will use.</li><li>If you are powering multiple different models of LED strip from the same power supply, calculate the total consumption of each model and add those totals together to get the combined total of all the strips.</li></ul><p>The basic formula for the above looks like this:<br>[LED strip wattage] x [LED strip length]</p><p>It&apos;s fine to round the result to the nearest watt for convenience.</p><p>You can use power consumption in W/ft or length in feet &#x2013; just remember to convert units as needed. Tip: If you enter the formula into Google, it will calculate it and handle unit conversion for you. E.g., searching &quot;8.4 W/m * 26 ft&quot; gives the result &quot;66.56832 watts&quot;.</p><h3 id="calculating-led-module-power-consumption">Calculating LED module power consumption</h3><p>The above can be applied to LED modules as well, just using the wattage per module instead of wattage per meter and number of modules instead of length.</p><p id="isPasted">To calculate the total power consumption of your LED modules:</p><ul><li>Find the power consumption of your LED modules. On our site, this is listed in watts per module in the &apos;General specifications&apos; section of the description on the product page.</li><li>Multiply the power consumption by the total number of LED modules you will use.</li><li>If you are powering multiple different models of LED modules from the same power supply, calculate the total consumption of each model and add those totals together to get the combined total of all the modules.</li></ul><p>The basic formula for the above looks like this:<br>[LED module wattage] x [Number of LED modules]</p><p>It&apos;s fine to round the result to the nearest watt for convenience.</p><h3 id="calculating-the-total-power-consumption">Calculating the total power consumption</h3><p>To calculate the total power consumption of your installation, take the consumption of your LEDs and add the requirements of any controllers or other devices you will be powering from the power supply. This gives you the total power consumption you need to support.</p><p>Most controllers and similar on our site have their power requirements listed in the &apos;General specifications&apos; section of the description on the product page; and if not, it should be in the spec sheet. They usually use an insignificant amount of power themselves (less than 1W), but it&apos;s always worth checking just in case, especially if your LEDs consumption is very low and even a little bit more wattage will affect the size of power supply you need.</p><h2 id="choosing-the-right-power-supply">Choosing the right power supply</h2><h3 id="allow-some-headroom-in-wattage">Allow some headroom in wattage</h3><p>Choose a power supply that can provide at least 20% more power than your total calculated consumption. This provides some headroom to allow for heating, current surges, etc., which will help prevent the power supply failing in edge cases and will generally improve its lifespan.</p><p>For example, if you calculate your consumption is 130W don&apos;t get a 130W or 140W supply, get a supply with at least 130W * 120% = 156W of output power.</p><h3 id="select-the-correct-voltage">Select the correct voltage</h3><p>Ensure the voltage of the power supply matches the voltage of your LED strips or modules. Common voltages are 12V or 24V. The voltage of a strip is usually printed on the strip by the solder pads. For modules, it&apos;s usually labeled on them; either embossed in the housing or cover, or printed internally and visible through the cover.</p><h3 id="consider-the-installation-environment">Consider the installation environment</h3><p>Consider the environment where the power supply will be installed. If it&apos;s an area prone to moisture or dust, look for a power supply with an appropriate ingress protection (IP) rating.</p><h3 id="quality-and-safety-tips">Quality and safety tips</h3><ul><li>Opt for a power supply with short circuit protection to safeguard your LED strips and power supply.</li><li>Choose a power supply from a reputable manufacturer to avoid quality issues.</li><li>Ensure the power supply you select has the necessary certifications for your project (e.g., UL, CE, RoHS).</li></ul><p>All the power supplies offered on our site are great options!</p><h2 id="practical-tips">Practical tips</h2><h3 id="consolidating-power-supplies">Consolidating power supplies</h3><p>If your project has multiple sections of LED strip or modules, consider whether you want a separate power supply for each section or a single larger power supply for everything. Separate power supplies can be easier to manage and replace but using a single power supply reduces complexity.</p><p>This is especially important if you do not use any LED controllers, as then the LEDs will be controlled via the power supply. If you need to be able to control the sections individually, you will need multiple power supplies.</p><h3 id="installation-location">Installation location</h3><p>Install the power supply in an accessible location where it can be easily reached for maintenance or replacement.</p><p>Prefer installing it in a well-ventilated area to prevent overheating. For smaller installations, such as under-cabinet lighting, installing the driver inside a cabinet or similar is acceptable. For high-power installations they should be in the open air, or actively cooled if enclosed.</p><h3 id="future-expansion">Future expansion</h3><p>If you plan to expand your LED project in the future, consider choosing a power supply that can accommodate the additional load to avoid the hassle and expense of upgrading it later.</p><h2 id="conclusion">Conclusion</h2><p>Choosing the correct power supply is a vital step in your LED project. By understanding your project&apos;s total power consumption, matching the voltage, considering the installation environment, and focusing on quality and safety, you can select a power supply that ensures the longevity and performance of your LED lighting. Remember to reference the &apos;General specifications&apos; on our product pages for accurate power specifications and plan with a forward-thinking approach for a successful LED installation.</p>

Choosing the correct power supply for your LED project

Electrical note: Power (watts; W) in a DC system is simply voltage (volts; V) multiplied by current (amps; A). So if you have a 12V power supply providing 5A, there is 12x5 = 60W of power involved; or put another way, a 300W 12V supply can provide 30

<p><strong>Electrical note:</strong> Power (watts; W) in a DC system is simply voltage (volts; V) multiplied by current (amps; A). So if you have a 12V power supply providing 5A, there is 12x5 = 60W of power involved; or put another way, a 300W 12V supply can provide 300/12 = 25A of current.</p><h2 id="power-and-efficiency">Power and efficiency</h2><p>LEDs are DC (direct current) devices &#x2013; you can&apos;t run them off the mains, which is a high voltage AC (alternating current) supply. To convert and condition this mains power you need a PSU (power supply unit), also known as a driver. This is commonly called a &apos;transformer&apos; in the industry, but that is quite incorrect.</p><p>A PSU takes the AC mains supply and converts it into a regulated DC supply (the DC output does not fluctuate, hence it is regulated). The power supply may support a quite a large range of input voltages (perhaps 90 to 260V), but the DC output remains at a constant voltage. Common DC voltages are 5V, 12V, and 24V, but others are also available (such as 48V).</p><p>Most PSU&apos;s are described as being either &apos;switch-mode&apos; or linear regulators. Linear supplies are not efficient and require lots of heat sinks and heavy transformers, whereas switch mode supplies are now the industry standard and are very lightweight and efficient.</p><p>Typical efficiencies for switch mode supplies are usually over 90%. What this means is that for a 300W output supply, it would only need about 330W mains input. Let&apos;s use this example to calculate a mains input requirement: Assuming a 120V AC mains supply, the current required would be 330/120 = 2.75A. This is not much at first glance, but on start up there is an inrush current which the local circuit- breaker must handle without tripping; the normal 15A circuit-breaker is more than adequate for 1 PSU.</p><p>How much current can this PSU give us at the DC end? We said it was a 300W supply and if it was a 12V system, it would be 300/12 = 25A. Should we run it with a 25A load? No, you have to allow some head-room for the supply to allow for heating, current surges, etc. A usual value for maximum loading is 80% of the rated output. This means we can load this supply up to 80% of 300W; i.e., 240W; i.e., 240/12 = 20A max.</p><h2 id="mounting-and-cooling">Mounting and cooling</h2><p>We said earlier that switch-mode power supplies are very efficient; however, that little bit of inefficiency results in heat and has to be taken notice of. In our earlier example of a 300W 90% efficient supply, there is 30W of heat. In a closed box with no ventilation this is going to build up, and without any way for that heat to dissipate will lead to the supply failing. This is especially relevant if the box is exposed to sunlight, as that will additional heat.</p><p>Obviously, the supply should be protected from water, dust, and vibration and should have the correct IP rating.</p><h2 id="constant-current-vs-constant-voltage">Constant current vs Constant voltage</h2><p id="isPasted">A constant voltage supply attempts to maintain a fixed output voltage regardless of the load current. They will try to supply as much current as needed, until they either burn out or shut down (for models with overload protection).</p><p>A constant current supply is basically a constant voltage supply with built-in current limiting. It acts similarly to a constant voltage supply, but will decrease the output voltage as necessary (but within a certain range) to prevent more than the set current from being drawn, thus maintaining a &quot;constant&quot; current.</p><p>Which you use depends on what you need to power. Almost all LED strips are &quot;constant voltage&quot;, which means they must be supplied with a fixed voltage; these require a constant voltage supply. Other LED fixtures, such as downlights, spotlights, and many rigid LED bars and similar, usually require a regulated input current; these require a constant current supply.</p><p><br></p>

Understanding power supplies

Remember that the power coming out the DC end of the PSU, although at a lower voltage, will now be at a considerably higher current: eg for a 300W 120V input, 24V output supply, the mains input current is 300/120 = 2.5A, but the output DC current is

<h2 id="choosing-wire-size">Choosing wire size</h2><p>Remember that the power coming out the DC end of the PSU, although at a lower voltage, will now be at a considerably higher current: eg for a 300W 120V input, 24V output supply, the mains input current is 300/120 = 2.5A, but the output DC current is 300/24 = 12.5A. So this of course makes a huge difference to the choice of wire size &#x2013; <em>you cannot use the same type of wire to wire up both sides to the PSU.</em> Ohm&#x2019;s law will produce an ever-increasing loss of voltage in the wiring as the current and the length increases, and this in turn will show up as dimming of the LED brightness and warming of the wiring.</p><p>Avoid using long wires with large currents; it is better to locate the power supply closer to the center or to use additional power supplies. Long wires are prone to voltage drops (dimming) and fires (due to overheating).</p><h2 id="feeding-long-strips">Feeding long strips</h2><p>Inside the LED strip there is not much space for heavy wire, with the result is that the thin copper will cause a noticeable voltage drop (and therefore dimming). The thinner the LED strip, the worse the voltage drop becomes. For longer lengths, the strips should be fed from both sides or broken into smaller sections and fed from separate supplies or transformers with multiple outputs, as shown in the example below.</p><p><img src="https://attachments.gorgias.help/uploads.gorgias.io/qgaXzxaEqkpxvDWO/undefined-2d6d47c0-0bb6-454c-87a3-79d257fd7ee6" class="fr-fic fr-dii"></p>

Wiring from the power supply to the LEDs

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