Why does the LED lamp light up when the switch is off?

LED luminaires are gradually replacing incandescent lamps due to their economical energy consumption. They are used in private houses, apartments, street lighting, window and area lighting. Semiconductor devices provide a uniform luminous flux without harmful ripple or flicker. When using LED lamps, you can notice an unusual effect - glow after switching off. A dim lamp at night replaces the backlight and does not interfere with the tenants of the apartment. Electricity consumption for a weak glow is minimal. The reverse side of the glow is the development of the LED resource. Continuous operation leads to rapid burnout of the crystal.

The main causes of residual glow

Constant smoldering or blinking of a light bulb in the bedroom quickly gets boring. Residents start looking for the cause of the annoying behavior of the lamp. Electricians cite several factors as to why an LED light glows dimly after being turned off:

• use of a switch with LED backlight;
• wiring faults;
• errors when connecting the lamp to the power supply;
• low quality LED lamps.

After finding out the source of the problem, you can fix it yourself or contact a professional electrician.

LED lamp device

The structural features of the diode lamp explain the glowing or blinking effect at the moment of switching off. The main nodes of the LED device:

1. Glass diffuser or bulb - serves to evenly distribute the light flux.
2. Board with diodes - an aluminum base with conductive paths and a group of LEDs that create a luminous flux. Application of a special paste improves heat dissipation from the chips.
3. A driver is a high-tech device for converting current characteristics.
4. Radiator - a construction made of aluminum or its alloy to remove heat from the board.
5. Standard threaded brass base - the part does not differ in size and structure from an incandescent lamp base. This allows devices to be replaced using old cartridges. The base of the plinth is made of polymer. Its function is protection against electric current.

The driver is a 220 V stationary network AC converter. Resistors and capacitors are used as smoothing filters. A diode bridge is installed to rectify the current. In household lamps, linear converters are used, high-power devices are equipped with pulse drivers.

The ability of capacitors to store and then release current explains why, after turning off the light, the LED bulbs dim for a while. Installation of the element is required, otherwise the lamp will blink. Its capacity is small, the current ends quickly and the lamp goes out.

Illuminated switch

Switches with a luminous LED element make it easy to navigate in the dark. When using LED lamps, this convenient design causes them to partially burn. The diagram of the device explains why shutdown does not result in complete darkness.It contains a capacitor that stores voltage. Potential is spent not only for backlighting. Part of it goes to the LED lamp. There is not enough voltage for a full start, so the combustion is dull.

The glow is constant and periodic. In the first case, the device will continue to glow evenly, using part of the potential. In the second option, the light will light up periodically. These differences are explained by the magnitude of the current flowing. The capacitor needs time to charge, the lamp flashes, a weak light appears only when the charge is accumulating. This mode has a negative effect on the service life, the lighting device wasted idle resource.

Wiring faults

Wiring problems are the most dangerous type of malfunction. Not only does it harm the LED fixture, but it can cause a short circuit or electric shock. Malfunctions are provoked by the following factors:

• operation of wires for more than 15 years;
• use of aluminum cables;
• load exceeding the rated power of the wiring.

A break occurs in the insulation of the wire, through which the current flows. A small amount of interference is enough for a dim lamp glow. In apartments, communications are usually laid in a hidden way, so finding a damaged area requires effort.

Incorrect installation of the luminaire

When installing a luminaire with your own hands, incorrect wiring often occurs. In the junction box, the phase from the panel is directly connected to the lighting fixture, and the zero is sent to the switch. When the device is opened, the current does not stop flowing to the LEDs. The main danger of the situation is the voltage on the luminaire after shutdowns. A person, touching the device, will receive a current discharge.

Work to correct the switching of wires is carried out after a power outage.

Poor quality light bulb

LED devices are being installed to replace standard incandescent bulbs in order to reduce electricity bills. They are safer than energy-saving fluorescent lamps containing mercury vapor. The main disadvantage of LED lighting is its high cost. The desire of manufacturers to save on parts leads to the appearance of affordable, but low-grade products on the shelves. In half the cases where LED bulbs light up when the switch is off, the manufacturers are to blame.

Products of unknown origin have several main disadvantages: the lack of a driver, the use of a low-quality rectifier that provokes a ripple. Instead of a driver, a capacitor power supply is installed. It cannot provide stable output current parameters. In addition, the power and color rendering index are overstated. No warranty is given for this product. In order not to look for the causes of a malfunction, it is better to immediately purchase products from trusted brands.

How to fix the problem

The lamp may not turn off completely for months. At this time, the crystal is aging, its brightness decreases, and a resource is depleted. Having figured out why after turning off the light, the LED bulbs are dim, you can try to fix the problem yourself. This will require basic knowledge of electrical engineering and the ability to use tools. In the absence of skills, it is better to call an electrician.

What to do with the illuminated switch

If the lamp cannot be completely shut off due to the LED illuminated switch, the first tip is to replace the device. A model without additional functions will not cause a glow. The device with the LED element is installed in a different place where it will not create difficulties. Another way out is to remove the backlight. The switch body is untwisted, the wire to the chip is cut with a tool. Before starting the electrical work, turn off the mains power on the dashboard.

If an LED is required, a constructive solution is sought.

• Replace one of the LEDs in the luminaire with an incandescent lamp. She will take free current. This method is only suitable for appliances with multiple horns. The disadvantage of the method is that the energy-saving effect of lighting is reduced.
• A more laborious option is to install a resistor parallel to the lamp in the circuit. Its resistance should be up to 50 kOhm. The current will go to the resistor, the capacitor will remain without charge. The radio component is purchased in a specialized store. During installation, the legs of the parts are fixed on the terminal with wires.

Troubleshooting wiring

The problem with wiring is solved by replacing a section with poor-quality insulation. To search for a damaged place, you will need a special device - a multimeter. With open installation of cables, it will not be difficult to find damaged insulation. Hidden placement of wires will require the dismantling of decorative coating or plaster. Depending on the state of the communications, a separate section or the entire wire is replaced. After installation, the grooves are sealed with plaster mortar.

Incorrect connection of wires in the junction box is one of the reasons for the glow of the light bulb. The correct switching order: phase - to the switch, zero - to the light bulb. If the current goes directly to the socket, the device will not turn off. Reversing the phase to the switch will fix the problem.

How to choose the right LED devices

Poor quality lighting is a common reason an LED light is on when the switch is off. There are several rules to help you choose a reliable LED device:

• Reputation of the manufacturer - world-famous brands manufacture products in factories, observing technology and quality control. You can buy light bulbs from Osram, Philips, Feron, Gauss.
• The warranty period should be at least 3 years, for good models 5-7 years.
• Examination of the external condition - there should be no chipping or mechanical defects on the product. The size of the radiator is important, it must be optimally correlated with the lamp power. Finned structures reliably dissipate heat.
• Read the manufacturer's instructions, high-quality devices indicate whether they can be combined with dimmers, a motion sensor or a backlit switch.
• Before buying, it is worth assessing the level of ripple. The flicker is invisible to the naked eye, it is checked using the phone camera.

Price is one of the factors that determine the quality of LED luminaires. Inexpensive products have low performance. There are no important details in their design. Low-grade products are detrimental to eyesight due to flicker and color temperature.