LED Bulbs Lit with Switch Off

One of the most common queries that make us reach customers and users of our LED products is, without a doubt, ‘residual’ lighting that sometimes remain in some products (especially bulbs LED) LED after the light is turned off through the switch. There are many who believe that this is due to a bug in the product, but nothing is further from reality, since several are the main reasons to light bulbs that produce this, which I shall detail their most common solutions.

Switches with light (from presence)

Small light bulb (usually red) which is in the interior of some switches, serves as signage to be visible in the dark. This light is internally connected to the switch, making a bridge to this in order to pass by a small current which makes it look. This makes it flow a minimum power to the installed bulb, which can produce the installed LED light bulb is illuminated in a tenuous way.

This is the main reason in 90% of cases, but why not happened before with incandescent bulbs or low consumption?. The explanation is because previous bulbs (a power (W) far superior) receives this same residual current but, being so low and the power of the bulb so high, is not enough to generate a minimum of light. On the other hand, using low-power LED bulbs (< 12W), this minimum current if it is sufficient to generate a very shy but detectable light to the human eye.

What is the solution?. We could divide it into 2 options: the most radical (and also the most common) is removing the switch and cancel face-to-face light (neon) bulb completely. This residual current already does not reach the LED bulb and, therefore, not it would enlighten, occurring the same if instead of eliminating this little light opted to directly change the full switch by one without eye light (higher cost).

For those who have technical algunosconocimientos, there is the alternative of installing a small resistor in parallel with the LED light bulb, so is there evacuate the power and avoid the residual light. Just install this resistance of a value equal or greater than 220 k would be more than enough to keep the face switch light and prevent the lighting of the LED bulb. Another alternative technique with the same results happen for install a condenser from 0. 47uF, this being the most common solution among electricians.

Finally, and in the case that we are installing dichroic LED (halogen type) to 230V without replacement of halogen 12V transformer, would leave the converter module installed (transformer, reactor…) without load to the output, thus leaving the residual current in the transformer and not sending it to the bulb, turning off the light completely by pressing the switch.


Certain switches tend to be in places where its use is very regular (every day). For this reason, or even by the time that installed, maybe that your contacts are worn or that have created some “char” among these and allow you to spend a small leak intensity between them. This would generate the problem that such power would show off our new LED lamps.

In these cases, the solution would be by removal of the switch for internal cleaning and, if continue happening, substituting a new wall switch.

Poorly installed switch

Installation electrical loads are connected through a wired electrical installation consisting of two wires, one is the phase (230V) and one neutral. The work of switches are the cut phase thread when we act them (or phase and neutral), but here comes the error: in certain electrical installations are cutting the neutral wire. This fatal installation error can also make LED bulbs look so Dim after press the switch to turn them off. This is because any small bypass makes current flow from the phase to earth or any other electronic device, or even, but to a human body, since only a few milliamps LED may look.

To find a solution, you can find facilities that do not comply with the rules. One of the examples more clear is dismantling a box mechanisms and discover that the macaroni is crossed by several cables. In this case, the best option runs through contact with an installer, who can choose between the solutions and, even, if installation required, change phase to neutral in the own switch.

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Return by neutral current

This is the less common case of all. It is possible that some of our home appliances produce neutral return currents, which are very small, but they can do through our efficient LED to remain lit even with the off switch.

The solution in this case is more expensive, since there are to replace switches with new ones bi-polar that cut the phase and neutral to the button. If you do not find these switches, you can purchase one double and replace the two buttons with one single larger to avoid simultaneous pressing of both.

Original source: http://www.lightinghowto.com/led-spotlights/