LED lamps due to the economical consumption of energy gradually displace incandescent lamps. They are used in private homes, apartments, street lighting, window dressing and platforms. Semiconductor devices give a uniform luminous flux without harmful pulsation and flicker. When using LED lamps, you can notice an unusual effect - the glow after turning off. The dim lamp at night replaces the backlight and does not interfere with the tenants of the apartment. The consumption of electricity for a weak glow is minimal. The reverse side of the glow is the development of the LED resource. Continuous operation leads to a rapid burnout of the crystal.
The main causes of residual glow
The constant smoldering or blinking light in the bedroom quickly bothers. Residents begin to look for the cause of the annoying behavior of the lamp. Electricians call several factors why the LED lamp lights dimly after turning off:
- use of a switch with LED backlight;
- faulty wiring;
- errors when connecting the lamp to power;
- poor quality LED lamps.
After finding out the source of the problem, you can fix it on your own or contact a professional electrician.
LED lamp device
The structural features of the diode lamp explain the effect of glow or blinking at the time of shutdown. The main components of the LED device:
- Glass diffuser or bulb - serves to evenly distribute the light flux.
- The board with diodes is an aluminum base with conductive paths and a group of LEDs that create a luminous flux. Applying a special paste improves the heat dissipation from the chips.
- A driver is a high-tech device for converting current characteristics.
- Radiator - a construction made of aluminum or its alloy to remove heat from the board.
- Standard brass base with thread - the part does not differ in size and structure from the base of the incandescent lamp. This allows you to replace devices using old cartridges. The base of the basement 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. To rectify the current, a diode bridge is installed. In household lamps, linear converters are used, high-power devices are equipped with pulse drivers.
The ability of capacitors to accumulate and then give off current explains why, after turning off the light, the LED bulbs dimly burn for a while. Installation of the element is required, otherwise the lamp will blink. Its capacity is small, the current quickly ends 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 device diagram explains why disconnecting does not lead to complete darkness. It contains a capacitor that collects voltage. The potential is spent not only for backlighting. Partially, it goes to the LED lamp. For a full start voltage is not enough, so the combustion is dull.
The glow is constant and periodic.In the first case, the device will continue to glow steadily, using part of the potential. In the second version, the bulb will light up periodically. These differences are explained by the magnitude of the flowing current. The capacitor needs time to charge, the lamp flashes, a weak light appears only when the charge is accumulated. This mode negatively affects the life of the device, the lighting device is idling consumes the allocated resource.
Wiring Malfunctions
Wiring problems are the most dangerous type of malfunction. Not only does it harm the LED device, but it can cause a short circuit or cause electric shock. Faults provoke the following factors:
- wire operation for more than 15 years;
- the use of aluminum cables;
- load exceeding rated wiring power.
There is a gap in the insulation of the wire through which current flows. A small tip is enough for a dim glow of the lamp. In apartments, communications are usually laid in a hidden way, so finding a damaged site requires effort.
Incorrect installation of the lamp
When doing the installation of the lamp with your own hands, incorrect switching of wires often occurs. In the junction box, the phase from the panel is directly connected to the lighting device, and zero is sent to the switch. When the device opens, the current does not stop flowing to the LEDs. The main danger of the situation is the voltage on the lamp after switching off. A person touching the device will receive a discharge of current.
Work on correcting the switching of wires is carried out after a power outage.
Low quality light bulbs
LED devices are installed to replace standard incandescent lamps to reduce electricity costs. They are safer than fluorescent energy-saving fixtures containing mercury vapor. The main disadvantage of LED lighting is its high cost. The desire of manufacturers to save on details leads to the appearance on the shelves of affordable, but low-grade products. In half the cases when the LED lamps glow when the switch is off, the manufacturers are to blame.
Products of unknown production have several main drawbacks: the lack of a driver, the use of a poor-quality rectifier that provokes pulsation. Instead of the driver, a power supply from capacitors is installed. It cannot provide stable output current parameters. In addition, the power and color rendering index are overestimated. Warranty for such goods is not given. In order not to look for the causes of the 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 ages, its brightness decreases, and a resource is produced. Having figured out why, after turning off the light, the LED bulbs are dimly lit, 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 backlight of the switch
If the lamp cannot be completely turned off due to the LED-backlit switch, the first tip is to replace the device. A model without additional functions will not cause a glow. A device with an LED element is installed in another place where it will not create difficulties. Another way out is to remove the backlight. The switch housing is untwisted, the wire to the chip is cut with a tool. Before the start of electrical work, disconnect the mains power on the shield.
If an LED is needed, seek a constructive solution.
- Replace one of the LED devices in the lamp with an incandescent lamp. She will take the free current. This method is only suitable for appliances with several horns.Minus of the method - the energy-saving effect of lighting is reduced.
- A more time-consuming option is to install a resistor in the circuit parallel to the lamp. 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. When mounting the legs, 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 cable installation, it is not difficult to find damaged insulation. Concealed placement of wires will require the dismantling of the decorative coating or plaster. Depending on the state of communications, a single section or the entire wire is replaced. After installation, the strobes are sealed with gypsum mortar.
Incorrect connection of wires in the junction box is one of the reasons for the glow of the bulb. The correct switching order: phase - to the switch, zero - to the light bulb. If the current goes directly to the cartridge, the device will not turn off. Transferring the phase to the switch will solve the problem.
How to choose the right LED devices
Poor lighting quality is a common reason why an LED light is on when the switch is turned off. There are several rules that will help you choose a reliable LED device:
- Reputation of the manufacturer - world-famous brands produce products in factories, observing technology and controlling quality. You can buy bulbs of the brand Osram, Philips, Feron, Gauss.
- The warranty period should be at least 3 years, for good models 5-7 years.
- Inspection of the external state - the product should not have nicks or mechanical defects. The size of the radiator is important, it should be optimally correlated with the power of the lamp. Reliably remove heat from ribbed structures.
- Read the manufacturer's instructions, on high-quality devices it is indicated whether they can be combined with dimmers, a motion sensor or a backlit switch.
- Before buying, you should evaluate the level of ripple. With the naked eye, the flicker is imperceptible, it is checked using the phone's camera.
Price is one of the factors determining the quality of LED lamps. Cheap products are characterized by low performance. Their design does not provide important details. Low-grade products have a detrimental effect on vision due to flicker and color temperature.
