How to protect your apartment from power surges. Protecting home electronics and equipment from power surges and surges. Surge protection devices

Electrical energy is an integral component of everyday life modern people, no matter where they live - in the city or rural areas. It is difficult to imagine an apartment or house where there is not a single household appliance, and candles or torches are used for lighting. However, all household appliances, like lighting elements, which are powered through the home line, are at risk due to voltage instability. Exceeding the permissible limits by this indicator entails serious problems, up to the breakdown of expensive equipment and failure of the line. 220V surge protection for the home will help protect wiring and devices. In this material we will talk about how to protect equipment with your own hands from power surges in an apartment or in a private house.

What are the causes of voltage drops in the network?

The electricity supply system in our state is far from perfect. Because of this, the required voltage value is 220V, with which all household appliances, is not always maintained. Depending on the load on the network at a particular moment, the voltage in it can fluctuate within significant limits.

Voltage surges in our networks are not uncommon due to the fact that the vast majority of all elements of the energy supply system were developed several decades ago and were not designed for modern loads. After all, in almost any modern apartment there are many household energy consumers. Of course, this makes living more comfortable, but at the same time it significantly increases electricity consumption. The line cannot always cope with such loads, which results in frequent voltage drops.

One way to protect against network overvoltage on video:

There is no point in hoping that the old system will soon be completely redesigned to meet modern requirements. Therefore, protecting the power line and devices connected to it from power surges is a task in which owners have to think with their own heads and work with their own hands.

Now let's talk about the reasons why power surges occur in more detail. Typically, changes in potential difference occur without sudden surges, and modern technology, designed to operate in the range from 198 to 242V, is able to cope with them without damage.

We will talk about those cases when the voltage increases significantly within a fraction of a second, and then decreases just as quickly. This is the phenomenon called a power surge. Here are the reasons why it most often occurs:

• Simultaneous turning on (or, conversely, turning off) several devices.
• Break of the neutral conductor.
• Lightning strikes a power line.
• Broken wire inside the wire due to a tree falling on the power line
• Incorrect connection of cables in the common electrical panel.

As you can see, a voltage surge can occur due to various reasons. It is simply unrealistic to predict when it will happen, which means you should think about protection against voltage surges in advance.

An example of installing a voltage relay in the video:

How to protect equipment from overvoltage?

Certainly, best option protection from overvoltage of the home network and the devices included in it - this is a complete reconstruction of the power supply system with its subsequent maintenance by experienced specialists. But while it is still possible to completely replace the wiring in a private house, in multi-apartment buildings this is unrealistic. Practice shows that several dozen residents will almost never be able to agree on joint payment for such work.

It is unlikely that management companies will do this either. But it is useless to change the electrical wiring in a separate apartment - voltage surges will not go away, since they usually arise due to common equipment.

What can you do to prevent power surges from causing serious damage? Shouldn’t we wait until the utility workers and all the neighbors in the house have a desire to replace the general electrical wiring in the building? There is only one answer - choose reliable device to protect your home network from power surges.

Today, the following devices are used to increase the safety of home equipment and to minimize the likelihood of damage due to overvoltage:

• Voltage control relay (VCR).
• Overvoltage sensor (OHS).
• Stabilizer.

Sources should be mentioned separately uninterruptible power supply. They are close to the listed devices, but they cannot be called full-fledged devices for protecting lines from potential differences. We will talk about them in more detail below.

When power surges in an apartment occur infrequently and there is no need for constant protection from them, it is enough to connect a special relay to the network.

What is this element? RKN is a small device whose task is to turn off the circuit during a potential difference and restore the supply of electricity after the network parameters return to normal. The relay itself does not affect the magnitude and stability of the voltage in any way, but only records the data. These devices come in two types:

• A common unit, which is installed in the distribution panel and protects the entire apartment from overvoltage.
• Device, by appearance resembling an extension cord with electrical sockets into which individual devices are connected.

Visually pen the principle of operation of the voltage relay in the video:

When purchasing a relay, it is important not to make a mistake in calculating its power. It should slightly exceed the total power of the devices connected to the device. Individual RKNs that are included in the general network are not difficult to select - you just need to buy an element with the required number of sockets.

These devices are convenient and inexpensive, but they only make sense to use when the network is stable. If power surges occur constantly in it, this option will not work - after all, few owners will like the continuous switching on and off of the entire network or individual devices.

Voltage sensor

This sensor, like the RKN, records information about the magnitude of the potential difference, turning off the network in case of overvoltages. However, it functions on a different principle. Such a device must be installed in the network together with a residual current device. When the device detects a violation of the network parameters, it will cause a current leak, which, when detected, the circuit breaker (RCD) will de-energize the network.

In those lines that need constant protection against voltage surges, it is necessary to install a network stabilizer. These devices, being connected to the line, regardless of the potential difference applied to them, normalize the parameters at the output to the required value. Therefore, if power surges in your home network occur frequently, a stabilizer will be the optimal solution for you.

These devices are divided according to their operating principle. Let's figure out which one is suitable for different cases:

• Relay. Such devices have enough low price and low power. However, they are quite suitable for protecting household equipment.
• Servo-driven (electromechanical). In terms of their characteristics, such devices are not much different from relay ones, but they are more expensive.

• Electronic. These stabilizers are assembled on the basis of thyristors or triacs. They have sufficiently high power, are accurate, durable, have good performance and almost always guarantee reliable surge protection. Their price, naturally, is quite high.
• Electronic double conversion. These devices are the most expensive of all listed, but at the same time they have the best technical parameters and allow for maximum protection of the line and devices.

Stabilizers are single-phase, designed for connection to a home line, and three-phase, which are installed in the network of large facilities. They can also be portable or stationary.

Visually about stabilizers in the video:

When choosing such a device for yourself, you should first calculate the total power of the energy consumers that will be connected to it and the maximum values ​​of the mains voltage. We recommend that you seek the help of specialists in this matter - they will help you not get confused in the technical details and choose best option for a specific line according to characteristics and cost.

Uninterruptible power supplies

Now let's talk about these previously mentioned devices. Sometimes inexperienced users confuse them with voltage stabilizers, but this is not true at all. The main task of a UPS is to provide power to the connected devices for a certain time in the event of a sudden power outage, which will allow them to shut down smoothly while preserving the existing information. The power reserve is provided by the batteries built into the device. As a rule, uninterruptible power supplies are used together with computers.

Some UPSs, for example, with an interactive circuit or double conversion mode, have built-in stabilizers that can level out small differences in potential differences, but their price is very high, and they are not suitable for general network protection. Therefore, they cannot be considered a full replacement for the stabilizer. But to protect your PC during sudden power outages, such devices are truly indispensable.

Conclusion

In this article, we figured out why protection against surges in 220V mains voltage is needed for the home and what devices can be used to provide it. As readers can see, the most reliable way to protect household appliances from overvoltages is a powerful and expensive stabilizer.

However, this does not mean that nothing else can solve the problem of potential differences. In many cases, other listed devices will also be suitable. It all depends on the network parameters and its stability.

Modern home appliances contain sensitive electronics, making these devices vulnerable to power surges. Since it is not possible to eliminate them, reliable protection is necessary. Unfortunately, its organization is not the responsibility of the housing and communal services service, so you have to deal with this issue yourself. Fortunately, purchasing protective devices is not a problem today. Before moving on to the description and principle of operation of such devices, we will briefly talk about the reasons that cause voltage surges and their consequences.

What is voltage drop and its nature?

This term refers to a short-term change in the amplitude of the power supply voltage, followed by restoration close to the original level. As a rule, the duration of such a pulse is calculated in milliseconds. There are several reasons for its occurrence:

1. Atmospheric phenomena in the form of lightning discharges can cause an overvoltage of several kilovolts, which is not only guaranteed to damage electrical appliances, but can also cause a fire. In this case, it is easier for residents of high-rise buildings, since organizing protection from such predictable phenomena is the responsibility of electricity suppliers. As for private houses (especially with air inlet), their residents should deal with this issue on their own or contact specialists.
2. Jumps during switching processes when powerful consumers are connected and disconnected.
3. Electrostatic induction.
4. Connecting certain equipment (welding, commutator motor, etc.).

The figure below clearly demonstrates the magnitude of the lightning impulse (U gr) and switching impulse (U k) in relation to the rated network voltage (U n).

To complete the picture, mention should be made of long-term increases and decreases in voltage. The cause of the first is an accident on the line, as a result of which the neutral wire breaks, which causes an increase to 380 volts. No devices will be able to normalize the situation; you will have to wait until the accident is resolved.

Long-term voltage drops can often be observed in rural areas or holiday villages. This is due to insufficient power of the transformer at the substation.

What is the danger of fluctuations?

In accordance with acceptable standards, deviations from the nominal value are allowed in the range from -10% to +10%. During surges, the voltage can significantly go beyond the established limits. As a result, power supplies of household appliances are overloaded and may fail or significantly reduce their service life. With high or long-term differences, there is a high probability of ignition of the wiring, and, as a result, a fire.

Low voltage also threatens trouble, especially the compressors of refrigeration units are critical to this, as well as many impulse blocks nutrition.

Protective devices

There are several types of protective devices that differ in both functionality and cost, some of them provide protection to only one household appliance, others – to all those in the house. We list the well-proven and most common protective devices.

Network filter

The simplest and most affordable option for protecting low-power household equipment. It has proven itself to be excellent at surges up to 400-450 volts. The device is not designed for higher impulses (at best, it will take the blow on itself, saving expensive equipment).

The main protection element of such a device is a varistor (a semiconductor element that changes resistance depending on the applied voltage). It is this that fails when a pulse exceeds 450 V. The second important function of the filter is protection against high-frequency interference (occurring during operation of an electric motor, welding, etc.) that negatively affects electronics. The third element of protection is a fuse that trips during a short circuit.

Filters should not be confused with ordinary extension cords, which do not have protective functions, but are similar in appearance. To distinguish them, just look at the product passport, where full specifications. The absence of such should in itself raise suspicion.

Stabilizer

Unlike the previous type, devices of this class allow you to normalize the voltage in accordance with the nominal one. For example, by setting the limit within 110-250 V, the output of the device will be a stable 220 V. If the voltage goes beyond the permissible limits, the device will turn off the power and resume its supply after the operation of the electrical network is normalized.

In some cases (for example, in rural areas), installing a stabilizer is the only way to increase the voltage to the required level. Household stabilizers come in two modifications:

• Linear. They are designed to connect one or more household appliances.
• Trunk, installed at the entrance to the electrical network of a building or apartment.

Both the first and second should be selected based on the load power.

Uninterruptible power supplies

The main difference from the previous type is the ability to continue supplying power to the connected device after the protection has tripped or a complete power outage. The operating time in this mode directly depends on the battery capacity and load power.

In everyday life, these devices are mainly used to connect desktop computers, so as not to lose data in case of problems with the electrical network. When the protection is triggered, the UPS will continue to supply power for a certain time, usually no more than half an hour (depending on the characteristics of the device). This time is enough to save the necessary data and shut down the computer correctly.

Modern UPS models can independently control the operation of the computer via a USB interface, for example, close a text editor (after saving open documents), then turn it off. This is a rather useful function if the user was not nearby when the protection was triggered.

Surge protection devices

All of the devices listed above have a common drawback: they do not have effective protection against high voltage pulses. If this happens, it is almost guaranteed to disable such devices. Therefore, the protection must be organized in such a way that after activation it can be promptly brought into operation. working condition. SPDs meet this requirement perfectly. On their basis, a multi-level system for protecting the internal lines of a private home is organized.

One of the accepted classifications of such devices is shown in the table.

Table 1. SPD classification

An example of three-level protection is shown below.

Design features SPD.

The device is a platform (C in Fig. 6) with a replaceable module (B), inside of which there are varistors. If they fail, the indicator (A) will change color (in the model shown in the figure to red).

Externally, the device resembles a circuit breaker, the mounting is the same (for DIN rail).

A special feature of SPDs is the need to replace modules when varistors fail (which is quite simple). The modules are designed in such a way that it is impossible to install them on a platform with a different rating. The only serious drawback is related to characteristic features varistors. They need time to cool down; repeated exposure to lightning strikes significantly complicates this process.

Safety relay

In conclusion, we will consider voltage control relays (VCRs); these devices are capable of protecting household appliances from switching pulses, phase imbalance, and low voltage. They cannot cope with lightning impulses because they are not designed for this. Their scope of application is protecting the internal network of an apartment, that is, where providing lightning protection is the responsibility of electric companies.

The devices can be installed in the input panel, directly after the electric meter, for this purpose a DIN rail mount is provided.

In addition, modifications of devices are produced in the form of power extension cords and modules for sockets.

These devices can only perform a protective shutdown of the network; if the voltage goes beyond the specified limits (set by control buttons), after normalization of the electrical network it is connected. Stabilization and filtration are not performed.

Cautions

You should not trust the protection of your home to homemade structures; in domestic conditions it can be problematic to set up assembled circuit and test its operation in critical modes.

Without practical experience in organizing lightning protection, you should not try to implement it yourself; it is better to entrust this work to professionals. We recommend that you consider this part of the article as informational.

All manipulations with the electrical panel, devices and wiring must be carried out only when the power supply is turned off.

How to Simply choose a high-quality LV for an apartment or a private house, which is better, a LV or a stabilizer, a diagram for connecting the LV to a 220V network, installing the LV in a panel.

It is believed that all modern household appliances are automatically protected. Expensive plasma panels are already built-in control relay or stabilizer, but more often than not, a high potential difference “breaks through” the built-in stabilizers and the equipment burns out.

TEST:

4 questions about how you can protect your equipment from shocks

• How often do you experience changes?

a) every few days;

b) very rarely.

• Do the light bulbs in the apartment flicker (change brightness)?

a) yes, constantly;

• What is the average load power of all your appliances?

a) less than 4 kW;

b) more than 4 kW.

• Do you often get traffic jams?

a) no. Knocks out when we turn on several powerful devices;

b) yes, sometimes you even have to change the plugs.

Test results:

b, b, b, b - a relay will suit you. RN will protect your equipment from sudden surges. Also, you need to install a more powerful plug. Your plugs are designed to carry less total current than your electrical appliances assume;

a, a, a, a - a stabilizer will suit you. Your power consumption is not high, an inexpensive device will “calm down” the voltage in the network;

a, a, a, b - ideally, an LV and a stabilizer will suit you, this will protect the apartment/house from sudden surges and equalize the voltage to a constant norm.

5 main reasons for voltage drops in the 220V network

Mains voltage is rms, i.e. actual value of the potential difference in an AC electrical network current, accessible to consumers. Basic parameters of the AC network - potential difference And frequency, in Russia the standard is: frequency 50 Hz and 230 V.

Due to imperfections, the power supply system is not always able to provide 220 Volt stability. With a sharp, short-term surge, electrical appliances are ready to fail, despite the built-in fuses and voltage relays built into the device circuit.

The potential difference in the network can change noticeably not only because of problems outside the apartment or house. Deviations from 220 Volts occur due to increased load on the network from switched on devices.

The cause of the fluctuations is outdated elements of power supply systems. Modern systems energy consumption is excessive load wiring, it was not designed for such power at the time it was designed.

The reasons for the differences are as follows:

• Several electrical appliances are turned on (and then turned off) at the same time;
• The neutral conductor is broken;
• Lightning strike during a thunderstorm;
• Damage to wires on power lines;
• Incorrect wiring in the electrical panel.

Horse racing is out of our control, so you will need to protect your home network from this issue in advance.

The most reasonable solution to the problems of fluctuations is to completely reconstruct the power supply system. If you live in a private house, then completely replacing the wiring is realistic and quite affordable, but, in reality, this will only reduce the likelihood of surges; new wiring does not guarantee the absence of interruptions Power lines.

2 ways to protect against surges

Today, there are the following 3 types of devices that can save your equipment from sudden surges:

• RKN (Voltage control relay);
• Voltage regulator;

1 main reason that the UPS is not able to cope with the difference.

Uninterruptible power supply and stabilizer- Different things. Many people confuse these two types of devices, which is due to an illiterate description. UPS in stores and ignorant sales assistants.

Let's figure out why we need an uninterruptible power supply. UPS used with a computer. Its main task is to prevent sudden shutdowns and keep the batteries charged for some time.

What happens if there is a strong drop? If UPS contains a stabilizer (which is extremely rare), it will preserve the integrity of the computer; if it does not, it will fail. All other household appliances not connected to the UPS will be under attack.

2 types of relays to protect household appliances and equipment. Uzip or relay.

Voltage control relay(RKN) is a simple device that turns off the circuit when the potential difference deviates from the norm. A relay for protecting household appliances and equipment switches the circuit back on when the potential difference becomes normal.

RKN does not change the voltage, does not stabilize it, the relay reads the indicators and acts according to the network.

Why do you need a voltage relay (RN) for a 220V home network?

Relay there are two types:

1. Relay general type. It is installed in the shield, RN protects the entire house (or apartment) from surges. RKN It is sensitive, does not respond to surges within a microvolt, and turns off the current supply when the potential reaches a critical value. The critical value depends on the specific model RKN. Adjustment of such devices is very easy: for example, relays RN-113 can be set up in 10 minutes without any special knowledge; Setting up the Barrier takes even less.
2. RKN built-in It plugs into a power outlet and resembles an extension cord with 220 Volt sockets. It includes individual electrical appliances and RN can protect them from overvoltage. The design of the relay is very simple - a plate that bends when the voltage increases presses the automatic toggle switch. This is why there is a noticeable “click” when triggered.

1 tip on how to choose the right pH for an apartment or private house

If you decide to purchase a control relay, remember that you should carefully study its power (more than the sum of the powers of all electrical devices included).

A relay is a convenient device, but is not entirely suitable in areas where the network is unstable. In this case, the relay will turn on and off very often; few people will like the constantly flickering light. The relay will preserve your household appliances, but at the cost of comfort.

Protection against voltage surges in the 220V network

3 main differences between relays and each other.

All single phase relays (i.e. relay, operating in a single-phase network, a standard two-contact network with a desired 220 V) differ from each other in the following parameters:

• maximum switched load current (total current). These are relays with ratings of 16A, 25A, 32A, 40A, 60A, 63A. Relays with high load currents are installed in production.
• presence of a network voltage indicator;
• controls (knobs that allow you to adjust the acceptable range);

How to Avoid Connection Problems, 3 Relay Connection Mistakes

Consider the three most common mistakes that happen when connecting incorrectly voltage relay:

1. Connection of the zero with the protective conductor coming after the differential circuit breaker. This is most often done “out of habit”, in order to achieve zeroing.
2. Single-phase connections of the device. Also a common mistake: a phase is connected to a differential machine, but the zero passes by. Thus, the zero of a household outlet is connected not to a differential circuit breaker, but to a zero busbar.
3. Error in incorrect polarity. When one pole is connected, the terminals are swapped, so the supply phase is connected to the upper terminal, and the outgoing phase to the lower, the supply zero from the zero bus is connected to the lower terminal, and the load to the upper.

4 types of voltage stabilizers

Unlike a relay, which de-energizes the network until the voltage returns to normal, the stabilizer works in the other direction - it normalizes the network. They are connected to the electrical network and, regardless of the voltage in the incoming network, the output parameters are 220 Volts. If changes occur frequently, this device will be an excellent solution, because, unlike a relay, it does not turn off the current. With a stabilizer, you guarantee not only the safety of your household appliances, but also their continuous operation.

• Relay. Cheap devices with low power.
• Servo driven. It is also called electromechanical. Its power is higher than that of relay ones, and the price is also higher.
• Electronic. Their design includes semiconductor parts - thyristors and triacs. They are very durable, powerful and accurate. They are not cheap, but they are guaranteed to protect your equipment from surges and ensure a stable network.
• Electronic double conversion. The most expensive and most reliable stabilizers. Their operating principle involves stabilization and complete equalization of the potential difference. These stabilizers level the incoming network twice. They are perfect for homes with a very unstable network, where the voltage in the outlet literally “jumps.”

TOP 2: THE MOST POPULAR RELAY AND STABILIZER

Let's carry out full review main characteristics of the RN-113 relay:

4 diagrams for connecting RN-113 to a 220V network

RN-113 installed in the network after a circuit breaker or plug.

The lower limit is the minimum voltage at which RN turns on (if the potential difference is above the lower one) and turns off (if it is below the lower one)

The upper limit is the maximum voltage above which RN turns off the network.

The lower and upper limits of the barrier are set using the control knobs.

4 detailed circuits for monitoring voltage in a 220V network on a DIN rail

If the voltage rises above the upper pH, it will operate within 0.02 seconds - much faster than if the potential difference falls below the lower one - 0.12 seconds. This is logical - after all, a decrease is not as dangerous as an increase.

Diagram of detailed connection of the LV to a 220V network

2 diagrams for installing the LV in the shield

detailed connection diagram with contactor

detailed diagram of the LV connection - installation in the panel

Connection rules are regulated by SNiP 3.05.06-85 " Electrical devices " and SNiP RD 34.20.179 " Standard instructions for compensating capacitive ground fault current in electrical networks».

Let's conduct a full review of the main characteristics of the SVEN AVR-2000 LCD stabilizer:

As you can see, this popular stabilizer- a device that normalizes the output potential difference and automatically RN. At a voltage above 280 Volts (according to GOST, the maximum permissible 240 V), the stabilizer will turn off the network within 0.01 seconds. When the load current is higher than 15 Amperes (power about 3.5 kilowatts), the fuse will trip and the device will turn off. If the network is less than 100 Volts, the device will not work at all. The device helps to configure the barrier thanks to 2 control knobs.

The test results for this stabilizer model can be summarized in the following graph:

This graph clearly shows that in the range from 170 Volts to 280 Volts, the stabilizer maintains 100% power. If the voltage is critically low (100 Volts), the stabilizer outputs 50% of the power (which is absolutely harmless for all electrical appliances).

STILL IMPORTANT TO KNOW: 3 advantages and disadvantages of voltage relays and stabilizers

2 main arguments for and against. Which is better - RN or stabilizer?

From our comparative characteristics it is clear that dignity RN- lack of stabilizer. If your home rarely experiences fluctuations, the network is relatively stable, but there are sudden and very high spikes, then more suitable for you RN, its response speed is much higher and it will turn off the apartment in time.

If you have an unstable network, the potential difference is constantly low, after which it rises to normal in several jumps and fluctuates around 200-220 Volts, you need a stabilizer, it will level the network, and all devices will work more stable.

Here are examples from real life:

Alexander, 32 years old, Omsk

“A week ago there was a surge in the house. There was smoke coming out of the TV in the back and from the socket. The TV went off immediately. Things were even more fun for the neighbor: the refrigerator, plasma, two light bulbs and washing machine. We can only guess what the voltage was, judging by the burnt out light bulbs, it was 300 volts. Something burned out in every apartment. We consulted an electrician. It was decided to install the launch vehicle, it should have been done earlier"

Svetlana, 54 years old, Moscow region

“We’ve been living at the dacha for two years now. The light blinks constantly, it’s impossible to get used to it, it’s terribly annoying. We went to the administration, to the district service - no one cared. Country house? Be glad that there is light. My husband installed the LV, but it doesn’t do much good; he turns off the lights about 10 times a day. The stabilizer solved the problem, now the light does not blink"

We conclude: a stabilizer together with a LV - 2 in 1 is capable of completely protecting an apartment or house. The relay will ensure quick shutdown in the event of an extremely sharp jump, and the stabilizer will level the potential difference to normal 220 Volts.

ANSWERS TO 5 FREQUENTLY ASKED QUESTIONS

The lights in the apartment are constantly blinking, what should I do?

Constant flickering of lights indicates network “jumps”. This is extremely harmful for electrical appliances containing semiconductors, such as televisions, computers, and audio-video equipment. This can be corrected by installing a stabilizer.

RN installed. Now the lights turn off several times a day. What to do?

Every time the relay de-energizes the apartment, this means that the voltage has gone beyond the permissible range: it has either dropped too much or risen. If this happens to you all the time, then you have a very unstable network. You need a stabilizer.

How to calculate the power of the stabilizer that will suit me?

Take all the household appliances you have and calculate their total power. Remember, the refrigerator is always working, the light bulbs in the rooms and the TV: everything needs to be taken into account.

When connecting a relay and a stabilizer together, what should be connected to what?

On the incoming line you must first install the RN, then the stabilizer. The LV passes any voltage that falls within the permissible range, and the stabilizer will bring it back to normal.

Is the stabilizer mounted on a DIN rail?

No, these are large devices. They are not DIN rail mounted. They are sensitive to moisture and dust, they are installed only where it will be dry and clean.

Power surges are a common problem in suburban communities. Most often it occurs during cold weather, when many people use electric heaters. Breakdown of household appliances, accidents on the line - it is better to protect yourself from this in advance. In our material we tell you what devices will save your home from harm and help you wait out the “end of the world.”

Voltage surges primarily harm those household appliances that have electric motors and compressors - refrigerators, air conditioners, washing machines and so on. If there is a lack of power, their motors heat up but do not spin, which ultimately leads to a winding burnout. Low voltage sharply reduces the efficiency of heating devices, microwave ovens and incandescent lamps.

But all this is only half the story. Constant drawdowns indicate that the network is operating in emergency mode, with overloads. This means that sooner or later something will burn out in the network equipment. The most dangerous situation is the burning out of the “zero”. In this case, the voltage on the “phase” can sharply increase to 380 volts. Then, of course, all working electrical appliances will burn out.

It must be borne in mind that a break in the “zero” is not always a consequence of overloads. Accidents also happen due to bad weather: icing of wires, falling of trees during strong wind etc.

Voltage relay (RN)

These are smart devices that can break the network if the voltage in it goes beyond the user-specified values.

The most common are electronic relays. They usually have digital indicator, which shows the current voltage and operating mode of the device. Electronic LVs cost up to 5 thousand rubles; as a rule, they operate with a current of up to 16 amperes. This roughly corresponds to the power of electrical appliances of 3 kW (electric kettle + microwave and that’s it). In order for such a relay to protect the entire house, you will have to connect it through electromagnetic contactors (plus the cost of 600 rubles and additional space for 3-4 modules).

Electromechanical relays voltages are considered more reliable and can operate with currents up to 63 amperes (total power of electrical appliances up to 14 kW). Such relays usually do not have digital displays, but only indicator lights.

Please note that the voltage relay must have a higher operating current rating than the circuit breaker after which it is installed. For example, if you are using a 32 A “automatic machine,” then select a 40 A relay. With an electromechanical relay, this condition is easy to fulfill. With electronic it is more difficult. It is necessary to plan well which consumer groups will be protected by which devices.

One more nuance. If you install a single relay to protect the entire house, then during voltage sags you will be left completely without electricity. Protecting the refrigerator from overheating, the relay will turn off the current, and you will not even have light in the rooms. Therefore, for different groups of consumers there should be several relays - with different settings.

A voltage relay is not the cheapest device. Prices start at 2,500 rubles for Chinese samples from little-known manufacturers. However, in some cases, simpler devices can be used instead of relays.

Minimum/overvoltage circuit breakers (MVR).

This device is installed in the electrical panel on a standard DIN rail next to the circuit breaker. The circuit breaker is designed specifically to turn off the “machine” if the voltage goes beyond the limits. For this purpose, the breaker has a special lever, which is inserted into a groove on the body of the “machine”. The switch and breaker must fit together like a key to a lock, so it is better to buy them together.

Breakers cost from 150 to 700 rubles. But this one inexpensive solution has its downsides. The response threshold is set by the manufacturer and is not adjustable. The most common circuit breaker on the Russian market, RMM-47, has a lower operating threshold of 170 V and an upper threshold of 270 V. This device can protect not very sensitive equipment - electric furnaces, boilers, etc.

Surge protection devices (SPDs).

SPDs are designed to protect the network from the consequences of a lightning strike. If lightning strikes a power line or discharges somewhere very close to it, a voltage surge will form in the network. Over the course of some milliseconds, it increases tens of times higher than the usual 220 volts.

This can be fatal for “smart” equipment that contains electronic control units. By the way, most voltage relays are easily damaged by lightning strikes. Only some have special protection.

For installation in electrical panels, two types of SPDs are produced. The first type is able to withstand direct lightning strikes on power lines. However, it does not completely extinguish the voltage surge, but cuts off, figuratively speaking, only half of the wave. A surge protector of the second type will save you if a discharge occurs somewhere nearby. But it can completely extinguish the voltage wave after a device of the first type.

The ideal option for a country house (especially one built on a hill) is to have both types of surge protectors in the panel. Well, at a minimum you need to install a device of the second type. If lightning hits a power line directly, it will burn itself out, but it will save household appliances.

Prices for SPDs start from 300 rubles.

Network filters

This is perhaps the most popular device for protecting household appliances from power surges. And also the most useless thing.

The direct purpose of a surge protector is to suppress interference in the network that occurs during the operation of some devices. Such devices, in particular, include computer power supplies.

Interference generated by computers can interfere with the operation of stereo systems and televisions (modern technology, as a rule, is not sensitive to this interference, that is, it has built-in surge protectors).

Some models of surge protectors contain fuses or circuit breakers that react to overheating. But this is unlikely to save the connected device from a power surge. Rather, it will save the room from a fire, but only after a short circuit occurs in the electrical appliance.

And only a few network filters have built-in voltage relays. Moreover, these models cost no less than a relay that can protect the entire house.

Surge Protectors

These are the most effective devices for eliminating differences. They are able to “correct” the voltage: increase or decrease it if necessary. But they also have a number of disadvantages - they are bulky, heavy, produce noise typical of transformers and are quite expensive. What do you need to know when choosing a stabilizer?

These devices are relay and electromechanical. Relays can be installed in an unheated room. The quality of their work depends on the number of coils, the so-called “stages”. In inexpensive models there are few steps, and therefore voltage drops are noticeable. Electromechanical ones operate more smoothly, but they make more noise and behave unstably in the cold.

When choosing a stabilizer, it is important to pay attention to whether it has overvoltage protection. If not, then you will have to install a voltage relay in front of the stabilizer.

The peculiarity of the stabilizer is that it itself needs energy. And the lower the input voltage, the more current it “eats off” from the overall pie. This increases energy costs. But this is not the biggest problem.

If the tension in the village often sags and many summer residents have acquired stabilizers, then a real war begins between them. Of course, it is not the summer residents themselves who are fighting, but their devices. As the voltage drops, the stabilizers begin to take more and more energy. As a result, tension drops even more, and the appetite of stabilizers increases. Eventually, some of the devices overheat and shut down. Then the rest have a holiday: the power begins to suffice. But this will not last long until the devices that have left the struggle are rebooted. Then the war for energy begins again. It is clear that in this mode the stabilizer is unlikely to last for many years. For “severe” cases, it is better to provide an autonomous source of power supply.

Gasoline power plant, or gas generator

This device is, of course, not easy. It makes noise, smokes, requires fuel, periodic oil changes, preventative maintenance... But it allows you not to rely on the mercy of electricians and always have light, heat and the Internet in your home.

The main criterion for choosing a generator is power, and you need to take it with a margin of at least 20 percent. A modern home requires at least 10 kW, but if you limit yourself to a kettle, TV and refrigerator, you can keep within 4 kW.

Please note: appliances with electric motors may consume 3-4 times the rated power at startup. For example, a 500-watt refrigerator may require 2 kilowatts to run. By the way, it is advisable to make such calculations when choosing not only a generator, but also a transformer.

But in the case of generators, consider another important point. The vast majority of generators have two output sockets. And the power is divided equally between them. To get 4 kW on one line, you need to have an 8 kW generator.

You can, of course, take current from both sockets. But, as a rule, the wiring in the house is not suitable for this. So if you are just building a house, then immediately divide the energy consumers into two lines in order to use the generator’s power to the maximum.

Uninterruptible power supplies (UPS)

The UPS can be used for autonomous power supply of computers and other office equipment. However, some models can cope with power surges.

The simplest UPSs, also called backup ones, monitor the voltage and when it goes beyond certain limits, switch the computer to battery power. If the voltage constantly fluctuates, then these switchings occur frequently. As a result, the battery quickly fails.

More advanced models - linear-interactive - have a transformer in their housing. During voltage surges, it smoothes out the waves and does not disturb the battery. The battery is used only if the current completely disappears. Therefore, when choosing an IBR, study the nature of the voltage in your outlets in advance.

And may your home be safe!

Currently, the issue of a stable voltage in the electrical network is quite acute. Network organizations are in no hurry to reconstruct and modernize power lines, substations and transformers. Meanwhile, the situation is only getting worse, so voltage fluctuations in our networks are a fairly common occurrence.

Update 11/11/2018.
For those who doubt the installation of a relay to protect against voltage surges for their home or believe in the quality of construction and installation work in modern new buildings. Below is a screenshot of one of the latest.

According to GOST 29322-92 voltage in the power grid of our country should be within 230 V at one phase and 400 V between phases. But if you live in a rural area or near a city, then problems with constant value the voltages are very high, and in the city itself this cannot be ruled out, especially in the old housing stock. Voltage surges have a very detrimental effect on electrical appliances in the house. For example, due to low voltage, a refrigerator or air conditioner may burn out (the compressor will not start and overheat), the power of the microwave is greatly reduced, and incandescent lamps glow dimly. well and high voltage It will simply “kill” your household appliances. I'm sure many have heard about "zero burnout" in high-rise buildings, and how entire entrances are taken to workshops to repair household appliances.

The reasons for voltage fluctuations in the network are different:

• Shorting one of the phases to neutral, as a result there will be 380 Volts in the outlet;
• Burnout (break) of zero, if you have a low load at this time, then the voltage will also tend to 380 V;
• Uneven distribution of load across phases (misalignment), as a result, at the most loaded phase, the voltage decreases, and if a refrigerator and air conditioners are connected to it, then there is a high probability that they will break;

Example video showing the operation of a voltage relay

Special devices - voltage control relays - help solve the problem of voltage surges in networks. The principle of operation of such relays is quite simple, there is “ the electronic unit", which ensures that the voltage is within the limits specified by the settings and, in case of deviations, signals the release (power unit), which turns off the network. All household voltage control relays turn on automatically after a certain time. For ordinary consumers, a delay of a few seconds is sufficient, but for refrigerators and air conditioners with compressors a delay of several minutes is needed.

Voltage control relays are available in single-phase and three-phase types. Single-phase voltage relays disconnect one phase, while three-phase voltage relays disconnect all three phases at the same time. At three-phase connection In everyday life, single-phase voltage relays should be used so that voltage fluctuations on one phase do not lead to the shutdown of other phases. Three-phase voltage relays are used to protect motors and other three-phase consumers.

I divide surge protection devices into three types: UZM-51M from Meander, Zubr from Electronics and all the others. I am not imposing anything on anyone - this is my personal opinion.

Voltage relay Zubr (Rbuz)

This device is designed to protect against voltage surges (zero burnout). BISON is produced in Donetsk.

I will note the features of this voltage relay.

Voltage indication on the device - shows the voltage value in real time. This is quite convenient and necessary for assessing the voltage situation in the network. The reading error is low, the difference relative to the Fluke 87 high-precision multimeter is only 1-2 Volts.

Zubr voltage relays are produced for various rated currents: 25, 32, 40, 50 and 63A. The device, with a rated current of 63A, can withstand a current of 80A for 10 minutes.

The upper voltage value is set from 220 to 280 V in steps of 1 Volt, the lower - from 120 to 210 V. The restart time is from 3 to 600 seconds, in steps of 3 seconds.

I set the Zubr voltage relay, the maximum (upper) voltage value is 250 Volts, and the lower value is 190 Volts.

For devices with index t in the name, for example Zubr D63 t, there is thermal protection against internal overheating. Those. when the temperature of the device itself increases to 80 degrees (for example, due to heating of the contacts), it turns off.

Zubr voltage relays occupy 3 modules or 53 mm on a DIN rail and are only single-phase.

The passport and the wiring diagrams for the Zubr voltage relay do not say about current limitations, but in the old documentation it was previously indicated that no more than 0.75 of the nominal one.

Zubr voltage relay wiring diagram

Currently, manufacturers claim that the relay can be connected at its nominal value. If the rating of the Bison is less than the rating of the input circuit breaker, then you need to use a voltage relay - a contactor - in the connection diagram.

Relay warranty Voltage Zubr the manufacturer gives whole 5 years! Has very good feedback from colleagues - forum members. And just like Meander on the MasterCity forum there is a Zubra representative who is not afraid to communicate publicly. And by the way, it is indicative from the example of UZM and Zubr that representatives of manufacturers of quality products are not afraid to communicate on forums.

Video about voltage relay Zubr

Update (06/07/15). Currently, the Zubr voltage relay is sold in Russia under a different name Rbuz (the word Zubr is backwards).

This is due to the fact that in Russia the Zubr trademark is registered with another manufacturer and only the name of the relay has changed, but all the components remain the same.

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UZM-51M. The protection device is multifunctional.

Currently, UZM-51M has proven itself to be reliable and easy to connect.

UZM-51M is designed for current up to 63A, occupies 2 modules on a DIN rail (35 mm wide). In the standard version, the operating temperature of the UZM is from -20 to +55 degrees, so I do not recommend installing it in a switchboard outdoors. It is true that there is a range from -40 to +55, but I have never seen such on sale, unless you contact Meander JSC directly.The maximum setting for the upper voltage cut-off is 290 V, the lower threshold is 100 V. The restart time is set independently - this is either 10 seconds or 6 minutes. Can be used in networks with any type of grounding: TN-C, TN-S, TT or TN-C-S.

Connection diagram UZM-51M

Meander produces two more types of single-phase voltage relays - these are UZM-50M and UZM-16. The main difference between the UZM-50M and the UZM-51M is, perhaps, only that in the latter, as we know, you can set the triggering setting independently, while in the UZM-50M the setting is “hard”, the upper voltage limit is 265 V, and the lower - 170 V.

UZM-16 is designed for a current of 16A, so it is installed only on a separate electrical receiver. For example, in order not to wait 6 minutes for the UZM-51 to turn on, the refrigerator can be connected via the UZM-16, on which the turn-on delay is set to 6 minutes, and on the main UZM-51M to 10 seconds.

I set the maximum (upper) voltage value on the UZM-51M to 250 Volts, and the lower value to 180 Volts.

Meander also produces a three-phase voltage relay UZM-3-63, as I wrote above, such relays are used mainly to protect engines.

Good reliable surge protection. The UZM does not need to be connected with a contactor, as is usually done with other voltage relays. The device is manufactured in Russia. UZM warranty is 2 years. What’s important is that Meander’s representative is present on the most popular Mastercity forum, always gives advice on products, and also pays close attention to the comments of forum users, whose comments at one time helped improve the UZM-51M.

An example of installing UZM-51M in a three-phase switchboard for a country house, where UZM is installed in each phase.

Perhaps one drawback of the UZM-51M relative to other voltage relays is the lack of voltage indication. But the difference in price between the UZM and a voltage relay with a contactor allows you to buy and supply a voltmeter separately.

Voltage relay RN-111, RN-111M, RN-113 from Novatek

These voltage relays are manufactured here in Russia. As you can see from the title, Novatek offers three types of voltage relays.

RN-111 and RN-111M are practically the same device in terms of parameters; their main difference is that the RN-111M relay has a voltage indication, while RN-111 does not.

The upper voltage limit is from 230 to 280 V, the lower limit is from 160 to 220 V. The automatic restart time is from 5 to 900 seconds. These relays have a 3 year warranty.

Connection diagram for voltage relay RN-111

RN-111 is designed for small currents up to 16A or power up to 3.5 kW, but to connect a higher load, RN-111 can be switched on together with contactors (magnetic starters).

Connection diagram for voltage relay with contactor

This significantly increases the cost, since a good contactor will now cost about 4-5 thousand rubles, you will need a larger number of modules in the panel, as well as a circuit breaker to protect the contactor coil. The above diagram for connecting a voltage relay with a contactor for RN-111 is valid for any other relay, taking into account the features of its circuit.

The RN-113 relay is already more improved relative to the RN-111, the voltage ranges and AR time are the same as those of the RN-111, but the maximum current for which the RN-113 can be turned on is up to 32A or if the power is up to 7 kW.

Connection diagram for voltage relay RN-113

But I would not do this, since the contacts on the RN-113 are weak enough for a wire with a cross-section of 6 mm 2, and this is precisely the cross-section required for a 32A connection.

It is more reliable to connect RN-113 with contactors, without contactors maximum 25A. I don’t use voltage relays from Novatek in my switchboards, so I borrowed the photo from one of the electricians from the Avs1753 forum.

It looks, of course, beautiful, but such a connection takes 3-4 more modules and is twice as expensive in cost as if UZM-51M or Zubr were used.

But what happens with the RN-113 if you connect it without 32A contactors.

Unfortunately, I did not find any information about tests like the UZM-51M and Zubr on the forums.

Voltage relay TM DigiTop

Just like Zubr, these relays are produced in Donetsk. The manufacturer produces several series of devices with protection against power surges.

The V-protector series voltage relay is intended only for protection against voltage surges. Available for rated currents of 16, 20, 32, 40, 50, 63 A in a single-phase version, it has built-in thermal protection against overheating, triggered at 100 degrees. The upper threshold is from 210 to 270 V, the lower one is from 120 to 200 V. The automatic switching time is from 5 to 600 seconds. There is also a three-phase voltage relay V-protector 380, quite compact 35 mm (two modules), but the maximum current in a phase is no more than 10A.

The Protektor single-phase voltage relay has a 5-year warranty, and the three-phase relay only 2 years.

V-Protektor DigiTop voltage relay connection diagram

Digitop also produces a voltage relay and a current relay, VA-protector, combined in one device. In addition to overvoltage protection, the device also provides current (power) limitation. Available for rated currents of 32, 40, 50 and 63 A. All voltage parameters are the same as those of the V-protector. Based on the rated and maximum current, VA controls the load and, if the rated current is exceeded, turns off the network after 10 minutes, and the maximum - after 0.04 seconds. The device display shows both voltage and current. VA-protector warranty is 2 years.

Well, the most advanced of the series of voltage relays from TM DigiTop is the MP-63 multifunctional relay. Actually, everything is the same as with the previous VA-protektor, only MP-63 shows, in addition to current and voltage, also active power.

This MP-63 relay and V-protector were independently tested by members of the forum, the reviews are average.

I tried to cover in my article the most common surge protection devices. Of course, there are still manufacturers of devices for this type of protection, but there is very little information about their use.

Thank you for your attention.