I've seen a few e-shops with regular electronics, and I've found a lot of sockets and elongators with descriptions like built-in surge protection, pulse overcurrent protection, and so on. So let's go to the store and buy this extension in good faith that we will keep our electronics safe.
In fact, we have only fall into the illusion of security that traders claim by failing to provide any further details on the level of protection that they are able to provide in the description.
Many articles have been described on this subject. Their common denominator, however, is relatively complex and hence hardly readable to someone who does not directly or indirectly deal with this area. So, I try to read through accessible literature with the intention of translating a few important facts from this area into the language of ordinary people.
Let us therefore recall a few basic facts. Nominal voltage in most EU countries is 230 volts between phase and neutral conductors and the nominal frequency is 50 Hz. Any change of these values outside the defined tolerance is undesirable, as it can cause damage to property and, in the extreme case, to health and life. The quality of the grid voltage is described in EN 50160. The standard also allows for voltage fluctuations of ± 10% from the nominal value, which means that the maximum voltage range from 207 to 253 volts is allowed in the socket. Somewhere, such as datacentres, such a fluctuation is unacceptable, and therefore they use special technology for filtering (active and passive filters) and power stabilization (UPS), which are relatively expensive but also necessary equipment for safe operation of such sensitive devices. But what about us in the ordinary household?
Supply sources in modern electronics and appliances are designed to safely handle voltage variation ± 10%. Some simpler device does not register any fluctuations and the source of the laptop as well. What, however, can happen if the tolerances given by the standard are exceeded by interference in the electricity network? And what causes it at all? And what ways it can get to you?
The sources of interference are variable, let's say a few words about them as well. If we are living to the proximity of factory or hardworking neighbours with circular saws and electric welders, we can experience industrial disturbance as a consequence of switching off and shutting down large motors that are able to derive themselves as the right inductive load by generating overpowers. Disturbance can also be caused by accidental operation on the network. For example, during the Premier League halftime, 20 million English at the same time turns on a 2000W power boiler or they want to enjoy their favourite tea. This will cause a large drop in voltage. However, the dominance of the destructive effects of interference in a network have atmospheric effects, which are especially lightning. Obviously, we can figure out the situation when we have noticed distractions during the storms through the television screen (in the best case) or smudging on the radio. In the worst case, the lightning and the darkness (we love it at the champions league final) suddenly blinked. Let's give some attention to the phenomenon, called lightning.
Globally, lightning activity is relatively accurately monitored, and based on a clear map, we can see that although we are not one of the most exposed countries, we cannot afford to ignore the protection.
As NASA informs us, the average incidence of lightning strikes per square kilometre per year is about 5. Who wants to avoid lightning, the recommended destinations are Greenland, Antarctica or Kamchatka.
In order to know at least how much energy the speech is, let's know that the biggest energy strike takes about 10 to 50 μs, which is the time for a fighter to fly at a speed of about 1 cm. At this time, the current flows typically between 5 and 50 kA, which is a line current flowing in locomotive traction engines capable of move a 1000 ton train. These are approximate figures for lightning in nature because the only person who knew about the light when and where he struck to measure it accurately was Marty McFly in Back To Future. Correctly, it was 12 November 1955 at 22:04 J.
So we see that it is a tremendous energy in a very short time. If we wanted to imagine this, it is as if a dam had been ripped up on the slope of a narrow valley, and a rushing wave was driving down the hill. As we know, such a wave has, in addition to the devastating force of water itself, also secondary effects, and it is the flooded material it carries with itself and which also has a destructive effect on all obstacles standing in the way.
Therefore, if we return to lightning, in the case of direct or indirect intervention, we need to take into account three phenomena that, due to different laws of nature, manifest equally - dangerous overpass at the impact site and all the metallic conduits around. These three phenomena were called experts as follows:
What happens? Lightning transition will increase the potential of the earth to be transmitted to our earthing conductor and through grounding conductors (in the yellow-green pocket) to all connected devices not only for sockets but also for shields of signal cables, ie xDSL modems, routers, security devices, etc. Paradoxically, the protective element of our installation will cause over confusion to anything that is connected to the conductor via a conductor.
Inductive binding. What is it? By rapid passage of the lightning current, the electromagnetic (EM) field changes rapidly over a short period of time, and so there is an overvoltage in conductors near the lightning conductor, which again affects all connected devices. And it does not care if it is a power, coax or signal cable. And not just that.
If the EM field is large enough, it will reliably destroy all processors with high semiconductor integration, which is actually all the chips used in electronics. Of course, people in their creativity have appropriately used this phenomenon, so theoretically, this day may come when communication with tamtams and smoke signals will come again.
Capacitive binding. Since after a direct hit, the potential of all the cables in our model house will grow, it will behave like a well charged capacitor.
However if the conductor is connected at least through the power lines with the remaining objects in the vicinity, it does exactly that, when such a capacitor is scraped off. In this case, the joy of this accumulated power will also be shared by our neighbours. That is why we are talking about the capacitance.
Quite theoretically, if we have the rare fortune that a ball flash will come to us through an open window or a chimney, there will only functional source of light: a candle, because only it will be able to function after visiting this mysterious flash.
As we have shown briefly, overpower protection is not a paranoia but a real fact. As an example of the devices to be protected, consider a family home equipped with an Internet connection, satellite TV, security device, air conditioning and solar panels. All listed devices have one thing in common - they are connected by metallic cables (power or signal) to the home distribution, and thus allow for overcurrent penetration by the methods outlined above. So let's make a summary of points that need to be addressed.
We see, that if we want to protect this house, it is clear that it should be considered as a complex project, where it is to be consulted with experts who propose the appropriate types of surge protectors and their exact location. Both conditions must be met, otherwise the whole project is irrelevant. The foundation is, of course, honestly made and properly grounded lightning, which is nothing new. However, for some new ones, it is necessary to perform regular lightning revisions according to STN 33 1500 standard. For example, residential buildings, family houses and farm buildings are subject to a visual check every 2 years and a revision every 4 years.
In practice, this means that if we report the damage incident after the lightning strike and we do not have a valid revision report, it will be complicated to deal with the insurance company. We have the basis, let's go further with our model house.
Firstly we must explain a few concepts that are directly related to surge protectors.
In order to clearly determine where the overvoltage protection belongs, the above-mentioned standard STN EN 62305-4 was defined by the so- lightning protection zone (LPZ = Lightning Protection Zone) as follows:
Now a few words to mark surge protectors. In our and foreign literature we will meet two abbreviations:
We combine the surge protectors into three types with the task of driving the lightning current and pushing the surge into the ground. The description of the technical parameters itself would be given as a separate article, we will not deal with things like spark, varistor, nominal discharge current or lightning current. The detailed technical parameters are finally stated by each manufacturer of surges. That's the big difference between the specialist dealer and the regular commerce mentioned in the introduction.
Quite often, manufacturers offer so- Combined protection Type1 + Type2 (or referred to as B + C).
So we went down to the sockets and I suppose we have the answer to the introductory question. The Type 3 tripod in a 1/2-grade socket has a placebo effect in direct or near lightning strikes. It does only what it is intended to raise the overvoltage in the event of a remote lightning strike or the overheating caused by the working circle neighbour.
Proper and therefore effective protection against overpower is neither a simple nor a cheap matter, and consultations with experts are always required. After installation, minimal revision is also recommended before and after the storm and optimally after each storm. Every protection has its own fault-free operation.
We can ask if any precaution can be taken. Something can be done. If we have a home or a home from the inside near the lightning rod of the electronics, consider relocating. We can also do "unplug action" before the expected storm, so we will completely disconnect the electronics from the power supply and the antenna arrays.
PLN 64 / Mo
PLN 500 / Mo