Light bulbs on with the switch off?
One of the star questions that our clients send us about the LED products in the catalog is: Why do they bulbs Do they stay on if I have the switch off? The explanation is very simple and is based on a concept on which this publication will revolve. This concept is called "current or residual light" . This phenomenon causes LED products to be dimly illuminated in some cases, so this residual light is more annoying when the lights are off. Many customers believe that this phenomenon is due to a product failure, but nothing could be further from the truth, since the residual current depends on other factors that we are going to explain now and the recommendations to end this problem.
1 Switches with indicator light or presence
This type of switch is very common in areas where visibility is often very poor, such as garages and hallways. This switch provides us with a point of light as a guide to turn on the rest of the global lighting. This beacon (which is usually red, orange or green) is connected internally to the switch by bypassing it so that this small LED receives an amount of current to make it work. This small step of current that activates the LED of the switch is what in turn causes the bulbs controlled by that switch to remain on. But why? Doesn't this happen with old incandescent bulbs? The explanation is very simple. The waste stream has always been there. but it was not enough to generate an amount of illumination since the old bulbs were of higher wattage and need a minimum amount that this residual current cannot cover. We can say that it is an effect that has always been there. but we didn't realize it. On the other hand, LED bulbs, being so sensitive (and especially low-consumption ones) with a minimum current, are already capable of generating an amount of lighting. and what is the solution? We can say that there are two types of solutions, one of them more radical than the other. The first consists simply of change this type switch and change it to a normal one (without indicator). It may seem like it is sharp to the core and the most radical, but it is the one that is most used for practical purposes. The main problem if we opt for this solution is that we no longer have a visual guide that may be essential in some aspects. If this indicator is essential and cannot be overridden, we will have to choose this second option. To opt for this solution, it is also mandatory to have a series of concepts about electricity. It basically consists of placing a resistor in parallel. Another valid alternative is place a 0.47 uF capacitor (it is an approximate value) to avoid this problem.
2 Flashing with switch off
Another cause, and one that is usually quite common, is the switches in areas where they are used frequently. The constant use of the switches (or that they have been installed for a long time) can cause the contacts to wear out and by not closing the current flow 100%, they let that small amount of residual current escape that will cause. . Ensure that the LED lamps remain dimly lit. In these cases, the solution is to remove the switch and clean it of any small impurities it may have or replace it with a new one. Another very frequent use is to place the LED strips around the perimeter of the bathroom or on the bottom perimeter of the bathroom cabinet. In this way we have an indirect light source that we can use when the tasks we want to perform do not depend on an intense light source. To do this, you can use both 12/24 VDC strips like 220 VAC strips. Our professional recommendation is to use the first one because by working at low voltage we avoid possible serious incidents.
3 Badly installed switch
Sometimes many of those we consider "handymen" carry out their own installations, wiring, etc. The main task of switches is cut the phase so that the current does not enter the luminaires and they do not turn on. If the connection is not made correctly, that small residual current that causes the LED lamps to light up can escape. On other occasions, due to a bad connection, we get the wrong cable and what we cut is the neutral (return) instead of the phase. This means that when we turn off the switch, the bulbs continue to receive a current that makes them stay on.
4 Return current through neutral
This is probably the least common case of all the ones we have discussed in this post. It is possible that some of the electrical and electronic devices that we have in our home or workplace produce a series of return currents that will circulate through the neutral (blue wire) and enter the LED bulbs and luminaires, causing them to remain partially lit. There is a small alternative that consists of reverse the connection of the phase and neutral cables so that this residual current is not & ldquo; introduced & rdquo; in LED bulbs. It should be noted that this is the case, it is better to treat it with a specialist so that he can determine the origin and solve it.
