With the arrival of spring and then summer, we all enjoy the warmth, rain and even thunderstorms. May thunderstorms... After which the sun appears and everything turns green. But today we will talk about how a thunderstorm can affect a router or modem. If you have already encountered this problem, and your Internet has stopped working after a thunderstorm, or is not working at all Wi-Fi router, then let's try to figure out what can be done in this situation. I’ll also tell you how to protect your router during a thunderstorm so that it remains safe and sound.
We all know well that lightning and thunder can damage various electrical appliances. There are often situations when televisions, refrigerators, computers and other equipment that are connected to the power grid burn out during a thunderstorm. So, routers and modems are very sensitive to lightning strikes. They can suffer either due to a power failure or get hit through an Internet cable that is connected to the WAN port. Moreover, it seems to me that most often the router receives a discharge via the Internet. This is because these cables are laid anyhow and are in no way protected from lightning.
In this article:
- How a thunderstorm affects a router or modem, and how it can harm them.
- What to do if the Internet and/or router stop working after a thunderstorm.
- How to protect your router (modem) during a thunderstorm.
Why is the router afraid of thunderstorms?
As I wrote above, there are two reasons. Not counting a direct lightning strike on the router :)
- Power surge. In this case, most often the power supply of the router burns out. But the board itself may also suffer. There are cases when, after such a voltage surge, the power supply becomes very hot, or even melts. The router may stop responding to a power connection altogether, or only the power indicator will light up. It happens that all the indicators are constantly on. This depends on the specific model and indicates some kind of hardware failure.
- The occurrence and transmission of a discharge via an Internet cable. As a rule, the Internet cable is laid from house to house, and is in no way protected from lightning strikes. If the provider has not taken care to protect its equipment, then during a thunderstorm it can be seriously damaged. Moreover, all routers and computers (network cards) to which the network cable is connected suffer. Because a discharge passes through it. At best, only the WAN port burns out, or LAN card on the computer. In the worst case, the router board, or the motherboard and other computer components burn out completely.
It should be noted that not only lightning can cause harm. Most often during a thunderstorm it rises strong wind, which can close the power line, knock down a tree on it, etc. Which will entail a short circuit, which can also damage electrical appliances connected to the network.
What to do if the Internet and Wi-Fi router do not work after a thunderstorm?
First you need to determine what the reason is. There may be problems on the equipment side of the provider itself, or something with your modem, router, or computer. Or maybe both.
Perform all actions only after the thunderstorm has completely passed!
Be careful, the router's power supply may be hot or damaged!
Let's look at the different options:
1 Turn on your router and pay attention to the indicators. If they don’t light up at all, only Power lights up, or all the indicators are constantly on, then most likely the router is out of order. In this case, there are several options:
I did not consider the case where the router was clearly burned out. The body of the device itself, or the power supply, began to melt, smoke began to appear, etc. There, it seems to me, the reason and solutions are clear even without my advice.
2 The router is working, there is a Wi-Fi network, but there is no Internet connection. "No Internet access." Most often this happens for two reasons:
These are the breakdowns. First of all, determine the reason why the Internet stopped working after a thunderstorm. Problems with the provider, or with your equipment. If you have something, then look at how the modem or router works. Which indicators are on? Check the operation of the WAN port.
How to protect your router or modem during a thunderstorm?
Some tips on this topic:
- As soon as clouds begin to gather outside the window and you smell a thunderstorm, unplug your router from the power supply, disconnect the cable from the WAN port and hide it in the closet :). I'm serious. The best way– completely disable the router. Don't forget to disconnect the Internet cable. Moreover, I advise you to turn off computers and other equipment. Just unplug them from the outlet.
- Connect the router through a regular surge protector. In most cases it really helps. Such a filter is not expensive, but its effect can be quite good.
- It’s even better to connect the router through a voltage stabilizer. I understand that this is an additional expense, but if you have problems with the voltage in the electrical network, or you live in a place where lightning likes to fly, then buying a stabilizer may be the only solution. Although, if there is a strong discharge, then the stabilizers also burn.
Write in the comments how you protect your equipment from such natural phenomena. And have you ever encountered problems with the operation of your router, or the Internet after rain with beautiful lightning.
Many people have encountered the problem of network equipment failure after a thunderstorm. During this kind of natural phenomena, both individual ports and entire ports can “burn out.” network devices and even interconnected sections of the network. Therefore, it is worth taking care of protection from their consequences in advance. For this, there is a whole class of specialized equipment called. Today we will get acquainted with the types and operating principles of which.
What is lightning protection?
First of all, lightning protection is a device designed to protect network hardware from failure caused by static electricity. Which can occur even in the air, as a potential difference between two charges. The main reason for its occurrence, as a rule, is various atmospheric phenomena: rain, snow, lightning and even wind. However, it is also possible for static voltage to accumulate near various electromagnetic sources, such as high-voltage power lines, power cables and even ordinary electrical wires.
Often in technical and accompanying documentation for equipment, as well as in various types of descriptions and technical specifications, defence from static electricity, is referred to as ESD Protection and is measured in terms of the voltage it can protect against, usually specified in kilovolts (kV).
The static charge voltage, from which lightning protection protects, can reach 10-20kV (10,000 - 20,000 Volts). Therefore, in fact, this is protection from thunderstorms, and not from lightning, as some often think. There simply cannot be any protection from a direct lightning strike, since in this case the voltage reaches 1GV (one Gigavolt or 1000000000 Volts), and the current strength reaches HUNDRED THOUSAND (100,000) Amperes. But this happens extremely rarely, because according to statistics, the chance of lightning hitting your equipment is approximately 1:600,000.
There are two main types of lightning protection:
The first, as you yourself understand, is used in wired networks and serves to protect Ethernet ports. Used where part of the network runs through open areas. For example, when a cable is stretched between two buildings over the air, or when it goes from, located on the roof or mast, to your or.
And the second type is used in cases where the organization wireless networks or communication channels, an external one is used, for example, installed on the roof. To protect the high-frequency module itself from static discharge, lightning protection is installed in the gap between the antenna and the access point.
At the same time, some modern wireless access points intended for outdoor installation are initially equipped with built-in lightning protection high frequency path.
How does lightning protection work?
Classic lightning protection is essentially a diode bridge that has a protective diode. The basic operating principle of lightning protection is that when a potential difference of more than 6V occurs between the wires, the diode “opens” and shorts the wires to ground, where the static charge flows.
An approximate lightning protection scheme for LAN networks looks like this:
That is why it is extremely important element lightning protection is correct grounding, the current flow resistance of which does not exceed 2-3 Ohms.
IMPORTANT! Do not use lightning protection without grounding or with poor grounding!
Since current always follows the path of least resistance, if there is poor grounding, this path may be your cable, which can lead not only to equipment failure, but also to more serious consequences: electric shock or fire.
Application
As already mentioned, protection for LAN ports is installed in the network cable break on one or both sides. When installing lightning protection on both sides, both must be grounded. Also, it is mandatory to use a shielded cable. twisted pair(FTP) and shielded connectors at both ends. The connector shield must be well connected to the cable shielding core or foil.
Protection of the high-frequency path of wireless equipment, using additional connectors or pigtails, is installed between the antenna and the access point. Despite the fact that these types of lightning protection are often gas-discharge type, grounding is also a necessary condition its operation.
You can select and purchase the lightning protection equipment you need on our website.
A tradition has been preserved from Soviet times - to turn off everything from the sockets during a thunderstorm. But what to do with the refrigerator, because stormy weather can last several hours, and during this time it will leak? Or if you have an urgent project and you can't turn off your computer? Or if you are not at home?
Why can't you use electricity during a thunderstorm - or is it still possible?
There are hundreds of reasons to keep your technology on. Many do this with the hope that lightning strikes power lines once every 20 years, and this time it will carry through. But why play the lottery if you can protect yourself and safely use electricity. Let's figure out what exactly you should be wary of during a thunderstorm.
The myth that electrical engineering is a lightning magnet
As you know, electrical appliances do not attract lightning. This myth is very similar to the idea that you should not use mobile phones in thunderstorms - this is not true. This statement appeared after in 2006 in the British Medical Journal bmj.com An article was published stating that mobile phones aggravate the effects of lightning strikes. But there is not a word in the text that cell phones attract thunderstorms.
Interesting: the article talked about metal phones. There have been cases where, after a lightning strike, the metal body of the phone became hot and caused serious burns. But, the article was published in 2006, and now smartphone cases are made mainly of plastic, like Samsung, and glass, like the iPhone. The information from the article has already lost its relevance.
After the article was published, newspapers began to massively print headlines like “ Cell phones dangerous during a thunderstorm." Everywhere it was said that the victims were talking on the phone during the attack or that they had it with them. The topic resonated and began to spread even more. This is how this popular myth was born. But can electrical appliances actually attract lightning strikes?
How electrical appliances affect thunderstorms
In fact, turning off or on household electrical appliances has no effect on the thunderstorm. This is due to the specific nature of the occurrence of this natural phenomenon. A static charge accumulates in the clouds with a force of half a million amperes and a voltage of millions of volts. To discharge such energy, a neutral field capable of transmitting ultra-high power current is required.
Only the earth can absorb such energy. The natural barrier between the positive cloud and the negative ground is air, which itself is a dielectric. And as soon as the accumulated charge gains enough power to break through this natural insulation, lightning appears. Most often, an electrical discharge follows raindrops - the path of least resistance, and on the ground it is aimed at high objects: iron pipes, wet trees, lightning rods, etc. The tiny electromagnetic field of a smartphone or other equipment cannot in any way affect the charge of such power.
The technology does not attract lightning strikes, but it may suffer from them. To prevent this from happening, she must be protected.
How to protect equipment from thunderstorm weather?
Contrary to popular misconception, lightning never strikes the wires themselves. high voltage lines. They fall into pillars wet from rain and pass through them into the ground. But a passing ultra-high power discharge creates a strong electromagnetic field. Because of it, a high-power pulse appears in the power line.
Why is a pulsed discharge dangerous?
An electronic pulse moves along a conductor, enters the home network and enters electrical appliances through an outlet. Because of this all electronics with microcircuits burn out. The pulse discharge burns semiconductor elements (resistors, thyristors, etc.). As a rule, electronics after this are no longer suitable for repair.
Heavy-duty electrical impulses are not dangerous for heating electrical appliances, since it lasts less than a second and during this time does not have time to heat the metal to dangerous temperatures.
An electrical impulse from a thunderstorm can come into a house not only through power lines, but also through a telephone or Internet cable. In this case, all devices with a wired connection to the Internet will burn out.
A fire due to such a discharge is unlikely to occur, but there is a lot of harm from it. In a split second, the overcurrent manages to burn out the electronic boards. In order for there to be a source of fire, gasoline must be deliberately poured onto the board. Such a case can only happen once in a thousand. However, electronic equipment is expensive and requires protection.
How to protect yourself from a lightning impulse?
For protection, you need to buy a surge protection device (SPD) or, as it is also called, a surge arrester. In order for the charge to completely dissipate, it must pass through several degrees of grounded protection:
- SPD on a high-voltage line pole - conducts current over 100 kA;
- Class 1 (B) - conducts from 50 kA to 100 kA, installed in enterprises and administrative buildings;
- Class 2 (C) - removes from 15 kA to 50 kA;
- Class 3 (D) - conducts from 8 kA to 45 kA.
In apartments they often put class D, and in private houses C and D one after another - for greater efficiency. It is impossible to predict which power line pole will be struck by lightning. For example, if this happens nearby, there is a high probability that class D will not protect the network.
Class B is placed at the entrance to high-rise buildings, where wires with a cross-section of 25 mm2 or more are inserted. A thinner core cannot allow such a powerful impulse to pass through, so a spark gap should be placed on it high class it makes no sense.
A household SPD consists of a chemical semiconductor composition that passes ultra-high currents. A wire is connected to it on one side, and ground on the other. As soon as an ultra-high power pulse flows through the conductor, chemical composition passes it through itself into the ground.
To understand that lightning protection has worked, many manufacturers make the composition in such a way that changes color when discharged. This does not mean that the arrester is disposable. Some brands claim that their models are designed for 2-3 or even more operations.
If the arrester is inexpensive, it is better to replace it after the first operation and not hope for a second time. Moreover, the cost of budget analogues starts from 350 UAH.
Where to put protection?
Put often one arrester per power supply is not enough. This is not the only way for ultra-high surge discharge to enter your network. There is also a computer and telephone cable, they also need to be protected.
Internet cable
Often the provider's Internet cable is routed to power line poles. And if suddenly lightning strikes this pole, two impulses will appear at once, which will simultaneously flow into the house through the electrical network and the copper network cable.
If you had an SPD installed at the input and it removed one of the current pulses, then the second one will burn all the electronics in its path. The router and all computers connected to the Internet via cable will burn out, even if they were turned off at that moment. That's why, Internet cable requires a special lightning arrester.
There is no need to install it in high-rise buildings, since providers themselves protect their own equipment. Each Internet node on the floor is already equipped with lightning protection equipment. But there are exceptions to every rule, so check with your provider, whether you should install additional protection.
You need to be wary of thunderstorms if the Internet is carried out with copper twisted pair cables, but the optical cable does not conduct current.
Telephone cable
The situation is similar with telephone lines. They are independent of power lines and transmit ultra-high pulses through their own cable. If there is no protection and a discharge occurs, all telephone sets will burn out. In a private home, the consequences are not so terrible - one or two telephones will burn out. But, for example, all telephones and faxes in the office will burn out. And this is losses worth thousands of hryvnia. It is cheaper to install a spark gap that costs several hundred.
IN apartment buildings the operator must protect his own equipment from thunderstorms, but in Ukrainian realities this is not always the case. For example, in Ukrtelecom lines it is a lottery, the protection costs every other time. It is not uncommon for household appliances to burn out due to the lack of lightning protection provided by this operator.
Antenna cable
The so-called “Polish antennas” are gradually becoming a thing of the past. Nevertheless, they are still used in Ukrainian villages. Signal receivers are placed on 10-meter masts, most often metal, and a coaxial cable from them is led into the building.
Such antennas are the best targets for lightning. Once hit, the current pulse flows into the house and “kills” the TV. Like other equipment, after this it can no longer be repaired. In order not to buy a new “box” after each thunderstorm, better put lightning arrester for antenna cable.
How to protect a network with an electric generator?
Let's assume that you have a generator in case of power outages or other reasons. When the light goes out, the backup source turns on automatically through the ATS system. Where to put the arrester in this case?
If the generator is small (3-5 kW) and standing indoors, for example, somewhere in a barn, you can simply install a lightning arrester to the main line in front of the ATS. The likelihood that lightning will hit a backup source and create an impulse is negligible; it is more likely to strike the barn itself and start a fire. Therefore, in this case there is no point in protecting the backup line.
Another situation is if the generator installed outdoors. If there is no lightning rod, lightning can hit it, which will probably damage it. But this is not all the losses, because an ultra-high current will flow through the backup cable and disable the ATS system.
If during the strike the network was powered from a backup source, then a lightning discharge will hit it and destroy the electronics plugged into the sockets.
Install one lightning arrester after the ATS - wrong, because she will be “killed” by a discharge from the city network. If you install lightning protection in front of the ATS on the main line, then all the electronics will fail through the backup line. Therefore, in this situation the most adequate option is place two lightning arrestors in front of the automatic transfer switch- for reserve and city network.
How to protect your home from a thunderstorm?
Lightning strikes on buildings are accompanied by fires. The last sensational incident happened on August 22, 2017, when the building of the Court of Appeal of the Kharkov region was hit. The fire started from the roof, then the fire reached the second and first floors. total area The fire area was 1500 sq.m. And this is far from the only such case. Thunderstorms often cause fires in private households.
The probability of a hit depends on many factors: the height of the location, the location of taller buildings nearby, etc. If the house is on a hill, the probability is higher than if it was somewhere below. Also, if there are taller buildings nearby, it is likely that lightning will strike them.
But, even if the building is in a low place, the probability of a hit still remains. This may be caused by a coincidence. For example, while it was raining, a thundercloud formed just above your house. The impact will be on the roof or the nearest tall tree. To prevent a fire, place lightning rod.
This is a long mast with grounding installed at the highest point of the building. Through it, electricity is discharged into the ground, where there is a buried metal cube - this design better conducts ultra-high currents. Grounding the lightning rod must be independent and no way don't touch with network grounding. It is better to separate them to the maximum possible distance.
If the grounding of the lightning rod and the electrical network come into contact, the pulse discharge will enter the house through the sockets. Lightning current does not care whether it flows through phase, neutral or ground.
When planning a lightning rod, move the external network wires away from its grounding loop, otherwise a lightning strike will provoke a pulse in nearby conductors.
Use electricity in any weather
If you install modular lightning arresters in the shield, your equipment will be safe. This way, you can use the Internet on your computer even in stormy weather and not be afraid that all electrical equipment will “burn out.” The minimum kit for a private home costs about 1000 UAH. (may be more expensive, depending on the manufacturer). It includes:
- Class C and D lightning arresters;
- lightning arresters for internet cable;
- lightning protection for telephone line.
This set enough for 10-15 years, and maybe more, if your home is not located at the epicenter of the formation of thunderclouds. This is enough not to twitch from every flicker in rainy weather and don’t run around pulling everything out of the sockets when thunder sounds.
Increased thunderstorm activity in the summer season forces people to take protective measures against the destructive effects of strong lightning discharges. You can protect yourself from powerful discharges of natural electricity using modern electronic means, such as voltage stabilizers and arresters. There are lightning protection options for a wide variety of equipment traditionally used in the home (including network routers and other elements of communications).
Lightning protection of electrical networks
A direct lightning strike into a house is fraught not only with the threat of causing direct damage to the structure, but also leads to the formation of strong electromagnetic fields and induced currents. These physical effects cause significant voltage surges that can damage any equipment that is connected to a household electrical outlet during a thunderstorm. Routers, network switches (switches) and computers are especially often affected by thunderstorms. When electrical discharges are directly exposed to electrical wiring, the wires may melt and a short circuit may occur, often leading to a fire.
In order to prevent possible consequences of a thunderstorm, it is customary to use special technical means. They limit voltage and reduce the effect of electromagnetic interference. Such lightning protection means include:
- special arresters;
- voltage stabilizers;
- surge suppressors OVR and other similar devices.
Please note that the functions of a pulse arrester and a limiter are combined in a number of modern electrical appliances, so their division into individual species purely conditional.
Types of stabilizers
Stabilizers, as a rule, are used to protect networks from sudden surges in supply voltage caused by interruptions in the power supply or poor quality. However, in certain situations, these devices can provide protection to electrical networks from lightning that strikes during a thunderstorm.
There are three types of voltage stabilizers:
- the simplest regulators of the “LATR” type;
- relay type systems;
- triac stabilizers.
For guard electrical networks against thunderstorms, only fast-acting samples of the second and third types of stabilizers are used, providing the required response speed to a lightning discharge.
Additional Information. Industrial stabilizers with lightning protection, equipped with a special discharge unit, are optimally suited for protection from natural electricity.
In this case, the most preferable are devices based on triacs, operating on the principle of key switching of power circuits. The only drawback of such stabilizers is their high cost.
Arresters (surge suppressors)
The use of limiters as an element of protection of electrical equipment has now gained wide use, which is explained by their relative low price and effectiveness of action. There are three known modifications of these devices, each of which is assigned its own class, similar to the characteristics of network circuit breakers(classes B, C and D respectively).
First-class devices maintain the functionality of power circuits by diverting dangerous interference to the ground. The device is made in the form of a modular design with a hermetically built-in spark gap that responds to overcurrents.
Such a block is installed in the distribution board in the input cable (before the electric meter) and provides protection against the transfer of dangerous interference to the protective conductor PEN. Devices of this class are installed at industrial facilities, government agencies and institutions, as well as in buildings that are part of large residential complexes.
The second type of arresters (class C) are completely similar in functionality to those discussed above, with the only difference being that they can also be triggered by normal switching, accompanied by current surges in the electrical network.
And finally, class D devices are intended to protect individual consumers connected to a given electrical network from lightning. They are installed directly in the user's power sockets, protecting electrical wiring from surge voltages.
With the help of such built-in devices, it is possible to protect a computer from thunderstorms, as well as ensure uninterrupted operation of the router in the apartment.
Telecommunications Security Devices
Despite the fact that coaxial cable networks are highly resistant to external force fields, under certain conditions (most often during a thunderstorm) they are quite vulnerable. The situation is similar with the so-called “twisted pairs”, which also need protection from strong electromagnetic interference and overvoltage.
To eliminate all of these threats, the industry has developed devices called “GZ-RS485-T”, which protect two-wire twisted pair cables both from interference and from secondary electrostatics. The efficiency of equipment of this class is ensured by shunting interference to the ground bus or automatic shutdown channel
It is also necessary to touch upon the issue of security of satellite communication lines. When organizing the operation of such channels with the professional name “satellite” (SATELLITE LINE), overvoltage protection is also provided using special equipment.
We looked at how to protect a house from a lightning strike using a lightning rod, but protective measures are not limited to this. We will talk about what else threatens us and how to protect ourselves from these threats in this article.
As was said at the very beginning, organizing external defense is not enough. We only remove the risk of direct lightning striking a house and other objects located on a personal plot. Unfortunately, thunderstorms can affect objects that may even be located off-site. But the result of such exposure poses a serious danger to the home. In real conditions, such an impact is more common than lightning striking a house directly.
Internal surge protection
The channel through which hazardous effects can be exerted is external electrical and communication networks. So, if lightning strikes, for example, electrical networks even a few kilometers from country house, the damage could be significant. From failure of electronic devices and electrical equipment to actual fire. This effect is usually called impulse overvoltage. It should be noted that, in addition to a thunderstorm, such an overvoltage can be caused by other reasons, for example, an accident at a substation.
There are usually two causes of overvoltage caused by thunderstorms. The first is a direct lightning strike into a network, most often an electrical one. The second is a lightning strike near the network. The fact is that with such a blow, electric field, and we get the induced electricity, which causes overvoltage. Lightning can strike close to home, or even outside personal plot. Hence the conclusion that it may be impossible to protect external networks from such influence, so it is necessary to protect networks directly in the house.
There are two important points to note. First, for such a protection system to work, first of all, the electrical networks themselves must be constructed at the proper level, in particular, a full-fledged potential equalization system must be implemented. Second important point, there is no universal means of protection against surge voltage. Therefore, the zonal principle is applied, and all protection devices are divided into classes and categories. Class “A” is of no interest to ordinary users; such equipment is intended for installation in substations. To protect a country house, equipment of class “B” to “D” is used.
Home protection
At the entrance to the building, the first level of protection is usually organized. For these purposes, class “B” equipment is used; its task is to limit the overvoltage to 2.5 kV. Typically, arresters are used for such purposes. different types. They are designed simply, schematically these are two contacts, between which the required gap is set. IN normal conditions such a gap acts as a dielectric. When a critical value is reached, a breakdown occurs, an arc discharge is formed between the contacts and the overvoltage is extinguished by grounding.
Arrester for installation at the input
Such arresters are installed at the very entrance to the house. This is done in order to avoid affecting the protective conductor and the potential equalization connection. The arresters are open and gas-filled. The parameters of open arresters depend on external influences, for example, such as air humidity. In winter, air humidity is lower, but thunderstorms are very rare in winter. Therefore, such a spark gap should protect against accidents at a transformer substation. The overvoltage parameters in this case are known, which allows you to select the necessary device. In the summer, when you should expect a thunderstorm, the air humidity rises, which means the level of operation of the arrester decreases. In this case, chosen based on winter conditions the arrester will provide reliable protection and in summer.
In a gas-filled arrester, the contacts are isolated from influences external environment, and the container is filled with inert gas under low pressure. Such devices have stable parameters, although they are more expensive.
Line protection
If for the entire house a voltage limit of 2.5 kV may be justified, then for individual house lines it is excessive. Therefore, a next line is needed that will protect individual lines. Unfortunately, there is an opinion that simple automatic machines are sufficient for protection. This is a dangerous misconception. The thing is that the machines have a slightly different purpose - they protect against emergency situations on the line, for example, a short circuit. But they cannot protect from external influences.
To protect lines, varistors are used; these are class “C” devices that protect against surge voltages up to 1.5 kV. A varistor, or semiconductor resistor, is most often produced in a ceramic version. In normal mode, they have a resistance of units of GOhm, that is, practically no current flows through them. When the critical voltage value is reached, the resistance drops sharply to tens of ohms; with a further increase in voltage, the resistance only decreases, so the discharge is extinguished to ground. For home networks (voltage 220/380 V 50 Hz), the critical voltage value is 470-560 V. Varistors are installed in distribution boards for each line that needs to be protected.
Device specific protection
The last line of defense is protecting your specific appliance. For these purposes, class “D” devices are used. This is especially true for electronic equipment that is sensitive to power surges. Devices we are familiar with uninterruptible power supply for computers, and even surge protectors can have built-in protection of the required level.
Typically, every device is not protected from such surges - for some household appliances such jumps do not cause harm, the cost of others is simply much lower than organizing such protection. For example, it is easier to replace an incandescent lamp than to protect it from rare power surges. In the same case, when protection is required, there are devices that can protect even a single outlet. Most often, this is a surge arrester already familiar to us, although designed for a lower critical level of surge voltage. Varistors, also specialized ones, can be used.
It is important to remember that without organizing the protection of the upper levels, and this is the protection of the house and lines, there is still no hope for reliable protection of a particular device.
Street electrical networks
We have practically figured out the electrical networks. Only the last case remains. The methods described above are designed to protect internal networks from overvoltage that is generated in the external network. But overvoltage can also occur in the internal network itself. This happens, for example, when it is necessary to connect outdoor devices to the electrical network. For example, this could be street lighting or anti-icing system.
In such cases, the output of electrical networks outside the house must be organized as a separate line. And as an additional protective device, a spark gap is installed, similar to the one installed at the entrance to the house.
Protection of low-current networks
IN modern house In addition to electrical networks, there are also low-current networks. Inside the house they do not require protection from thunderstorms. But if such networks are installed outside the home, then protection is necessary. An obvious example is a television antenna. A direct lightning strike is quite likely. Other low-current networks can also be routed outside the house. For example, to connect to a home computer network, two separate buildings. It is possible that such a network will be laid to control automatic irrigation or organize video surveillance. If you lay the cable underground, there will be no direct lightning strike. However, if we remember about the inductive shock, it becomes clear that this will not protect against surge voltage.
Low-current circuit protection device for DIN rail
To protect low-current networks, both arresters and varistors can be used, of course, with the appropriate parameters. But equipment using such networks is very sensitive to overvoltage, so they are more often used combined devices, which contain both a gas discharger and a varistor.
Low-current network protection device for free installation
Protective devices are placed in low-current panels, on DIN rails. If, of course, SCS is organized in the house (structured cable system). If not, then use free-standing devices, such small boxes designed to be mounted on the wall. Conveniently, devices can be designed for several channels at once, usually no more than four.
Now the reader knows everything about protecting his country house from thunderstorms. All that remains is to implement this knowledge in life.
Vadim Zhigulevsky, rmnt.ru