The necessity of lightning protection for LED street lights

KCOB LED STREET LIGHTS

Street Lights

Safty

For example, in a project, hundreds of lamps are often damaged for no reason. The common ones are like LED street lamps installed on a street. There are also LED fluorescent lamps, many of which use non-isolated power supplies, and are often found to be blown up during mass production. The root cause is here. They are all caused by surge voltages. The common ones are outdoor lightning strikes, or large loads are turned on, turned off, and voltage clutter. According to the written method, it is a very high voltage, which is instantly applied to the input power supply terminal, and then conducted from the input power supply terminal to the output terminal.

All LED lamps will be harmed by surge voltage. The value of surge voltage varies according to the actual situation, and the surge damage of LED lamps can be solved by LED driving power, such as the surge protection of some LED driving power. The ability to withstand voltage 4KV, some lower, some higher.

Kcob-street-light-with-good-anti-surge-lightning-strike-protection-

The PWM adjustment of the switching power supply requires several clock cycles, and if the input voltage changes instantaneously and the time is very short, the switching power supply has no time to adjust at all, and the performance at this time is that the instantaneous high voltage is transmitted to the output, especially now The step-down circuit for LED fluorescent lamps, because the load is connected in series in the 300V high-voltage circuit, the 300V high-voltage instantly becomes larger, and this high-voltage is instantly added to the output end. In this case, it is easy to damage the power supply.

Some people say that using TVS, choke coils, and X capacitors are actually not very useful. Because LEDs operating at normal currents are sensitive to voltage changes. We know that when the LED works at a stable current, such as a straw hat lamp, when the voltage applied to both ends increases by 0.1V, the current at both ends does not increase by a few percent, but may increase by tens of percent, or 0.5V. , not an increase of tens of percent, but an increase of hundreds of percent, that is, several times. Although the above components are still more than 400V, this voltage will still cause the output current to increase sharply, and the output will It is equivalent to a short circuit, or even a switch tube, which directly leads to the annihilation of the entire LED army. The phenomenon of isolating the power supply is to blow up the switch tube, which is the root cause. This is determined by the LED characteristics

Lightning strikes

are electrostatic discharges that typically carry millions of volts from a cloud to the ground or another cloud.

During transmission, lightning generates an electromagnetic field in the air, causing thousands of volts ( a surge ) to power lines and induced currents hundreds of miles away. These indirect attacks typically occur on exposed wires outdoors, such as street lights. Equipment such as traffic lights and base stations emit surges. The surge protection module directly faces the surge interference from the power line at the front end of the circuit. It transmits or absorbs surge energy, minimizing the threat of surge to other operating circuits, such as AC/DC power supply units in LED lighting equipment.

For LED street lights, lightning creates an induced surge on the power line. This surge of energy creates a shock wave, that is, a shock wave, on the wire. Surge is transmitted through this induction. The outside world is proliferating. The wave will create a tip on the sine wave on the 220 volt transmission line. When the tip enters the street light, it will damage the LED street light circuit.

Therefore, the lightning protection of LED street lights will be beneficial to its service life, which is currently required. Originally, the high-pressure sodium lamps and traditional mercury lamps used in the past were designed with high-pressure bulbs, which themselves have the effect of lightning protection. In recent years, LED lights have gradually become popular, and LED lights require a lower power supply voltage. Generally, a power supply is used to convert alternating current into direct current to drive, which makes the lightning protection of LED street lights themselves. Plan lightning protection modules.

The importance of street light lightning protection is determined by the concept of investment recovery period. Because LED street lights are about twice as expensive as traditional street lights, and the government’s initial investment in procurement is relatively large, it is necessary to gradually earn back the cost by saving electricity expenses during the operation process. Therefore, the life of LED lights is very important . . If the LED lamp is broken during the investment recovery period before the cost is paid back, it needs to be repaired by other money, and the labor cost paid during the repair is twice as expensive as the installation. Therefore, in the LED era, to complete the role of LED power saving and money saving, it is necessary to ensure that its lifespan can reach your expectations, that is, the shelf life of the product should be longer. In order to save costs and ensure that the street lights are not damaged during the investment recovery period, it is necessary to increase the reliability . This requires adding lightning protection modules to LED street lights to maximize economy.

------Some buyers generally pay attention to visible indicators such as brightness, lighting angle, light color, power consumption, etc. when purchasing street lamp specifications , but often neglect the invisible indicator of lightning protection. Not only the United States and Europe, but also in countries with high lightning strikes, such as Malaysia, India and other countries, have long established relevant standards that require local street lights to pass a set lightning protection test.

The three-level lightning protection specification

The key to the accurate use of the

surge protection module 1. The input wiring of the surge protection module is as short and thick as possible, and if necessary, multiple strands are connected in parallel to reduce the self-inductance of the wires, so that the surge protection module can absorb the surge impact energy at the input end as much as possible;
2. The equipment to be maintained needs to be installed after the lightning arrester, so that the input surge shock is attenuated by the surge protection module and then enters the rear stage, which has a maintenance effect;
3. Reduce the input wiring of the rear stage equipment and no surge maintenance The parallel spacing of the input lines of the module reduces the possible surge coupling path; 4. The surge protection
module wiring of the signal link is similar to that and follows the same guidelines.

For our vast number of buyers. It is enough to know the anti-surge value of LED lamps . When purchasing , try to choose certified LED lamps , or require power supplies produced by major manufacturers, such as Inventronics , Fred and Mean Well and other word-of-mouth brands .

in the United States has already been launched in the US national specification released in 2015, as shown in Table 1. The reason for the three levels is that there is a big difference between the east and west of the United States. The high mine area can reach 30 to 40 times, while the low mine area only needs 1 to 2 times. Therefore, three levels of specifications have been made, namely, 6kV, 10kV, and 20kV. This also gives flexibility to lighting manufacturers and local governments, and local governments can decide to apply the corresponding standards according to the actual situation.

As we all know, LED lighting fixtures cannot be directly used on 220V AC power supply. First, the voltage must be reduced. Equipment directly connected to the AC power supply may be damaged due to short-circuit and overload conditions caused by internal components or circuit failures of the bulb.

In addition to this, lightning surges or load switch transients can create voltage spikes or ring waves that can stress components and eventually cause damage, which then renders the lamp useless. Given that the value proposition of LED bulbs does not just lower energy consumption, but a longer lifespan, it will be critical to consider transient voltage maintenance in eliminating field failures promoted by the electrical environment.

Also, LEDs are extremely sensitive to high temperatures and should not exceed 85 °C . Keeping the temperature of LEDs and LED driver boards below this level is extremely important for their longevity.