Sudden changes in current in the network often lead to a malfunction of electrical appliances, including refrigerators. To protect home electrical equipment from sudden power surges, special devices are used to protect household appliances - this is a voltage control relay. Popular protection against power surges Barrier and Bison, they can be installed with your own hands according to the schemes.

Why you need to protect the refrigerator from power surges

Home refrigerators are powered by reciprocating units. At the time of a power outage or a decrease in power, the piston that distills the refrigerant through the refrigeration system is under high pressure and it needs a lot of effort to start the entire system. It takes about 6 minutes to turn off the power supply for a correct and safe start, but with a sharp jump, the compressor can fail, which leads to the breakdown of the refrigerator.

In some cases, the compressor can handle the voltage fluctuation, but its service life is reduced.

General voltage monitoring relay

Such a device covers all electrical appliances in the apartment. The relay provides a time delay of connecting to the power supply for 5 minutes, for example, Barrier. Protection against power surges Zubr allows you to make a delay of up to 10 minutes.

The disadvantage of common control relays is that for a certain time all the equipment in the house will be de-energized and you will have to wait 5-10 minutes. This is especially noticeable if voltage drops in the mains occur frequently.

Combination of several relays

For the comfort of everyday life, group relays are installed using a cross-module. One relay covers electrical engineering with compressor devices (refrigerator, freezer, air conditioner), and the other provides security, for example, TV, computer, etc. Each of the groups will be connected to the network at the same time: refrigeration units within 5-10 minutes, other electrical appliances within a minute.

However, the installation of group relays is quite expensive, in addition, space is required in the shield.

Easy to use relays with built-in timers. They allow you to independently adjust the delay time for supplying power to the devices. The advantage of such a device is space saving and low cost.

To protect the refrigerator from power surges in the apartment, it is enough to set the necessary time parameters to the relay timer.

It is possible to install a relay to protect the refrigerator from power surges with your own hands if you understand the power supply scheme of the apartment. The relay is the optimal protection for the refrigerator, designed to maintain its long-term working condition. While stabilizers or fuses will not fully provide such protection.

With an increase, as well as a decrease in the voltage in the network, which occurs as a result of accidents or a break in power lines, household appliances can completely fail. Often, power surges are also accompanied by a short circuit, which is a danger not only for various units, but also for people's lives.

Causes of power surges:

• often this happens due to the constant turning off or on of household appliances. For example, during an emergency shutdown of machines in a large factory, there will be a serious power surge that can lead to the breakdown of a large number of electronics;
• overvoltage in the network also occurs due to breaks in power lines or during a thunderstorm, when lightning discharges are observed near power lines. Therefore, the documentation for electrical appliances has advice on turning off household electrical appliances during a thunderstorm;
• consumer electronics break down due to increased voltage, which exceeds the norms for a particular device. This leads to uneven consumption of electricity.

The consequences of power surges

The problem of protecting household appliances from power surges is very important due to the high cost of most electrical appliances. In electrical networks of poor quality, the voltage may increase up to 250 V and fall below 180 V which is against the rules. If household appliances operate under overvoltage for a long time, this reduces the life of the devices, leads to insulation breakdown and various malfunctions.

Almost all manufacturers of household appliances strive to protect electrical appliances from unexpected surprises of overvoltage and network fluctuations by introducing protective elements into the design itself. For example, some refrigerators simply stop working when the voltage drops to 180V.

In refrigerators, as a result of unstable voltage in the mains, first of all, the electric motor fails. Moreover, at the same time, all residents of the entrance, whose household appliances have suffered from a sharp change in voltage, can simultaneously declare the problem. for example, it is designed to work with a voltage of 220V, and possible deviations may be 187V -242V. If the voltage is more than 242V for a long time, excessive heating of the starting winding may occur, which will lead to melting of the insulation and a short circuit. The result of all this will be a repair, in which all the main parts of the unit will have to be changed.

In Russia, the voltage of the electric current in the network is often low, below 187V, and also remains at this level for too long. In this case, the start-protective relay does not work, and the starting winding does not turn on. This leads to heating of the working winding of the electric motor, which necessitates an expensive one.

To prevent these problems, you must take the following measures:

• 1. Qualitatively make contact, which is expressed in the absence of loose sockets and plugs. First of all, it is necessary to ensure reliable contact between the plug and the socket, as this is a mandatory requirement for the operating rules of any type of refrigeration unit.
• 2. For you need to make a separate outlet, and connect other appliances in the kitchen to the rest of the power points.
• 3. In case of systematic voltage fluctuations, as well as power outages, it is worth buying an electric voltage stabilizer. This will save you money on ongoing refrigerator repairs.

In this case, it will always work without problems for many years, since the life of household appliances largely depends on high-quality power supply. Constant shutdowns and power surges are often accompanied by breakdowns of such equipment.

REFRIGERATOR PROTECTION

Having purchased a rather expensive refrigerator and having heard a lot of scary stories about how quickly they burn out from voltage drops in the 220V network, it was decided to equip it with a refrigerator protection device.

The choice fell on the schemerefrigerator protectionfrom Radio 7-2005. The machine can temporarily - for a couple of minutes, turn off the refrigerator from the network when the voltage goes beyond the permissible limits, or when the current in the load increases.

The circuit is powered by a VD3 diode rectifier with a quenching capacitor C1 and a VD2 zener diode. Mains voltage control produces op-amp DA1, the elements of which work as comparators. The rectifier on VD1 generates a proportional to the average rectified alternating, constant voltage. Resistors R2 and R6 regulate the upper and lower limits of the permissible range of mains voltage. Chip DD1 counts a five-minute delay interval for turning on the refrigerator. The LED included in the emitter circuit of the transistor VT2 is an indicator of the operating mode of the device. The current protection unit consists of a current sensor - a resistor R13, an amplifier on VT1, a capacitor C5, VD8R21, DD2.3, DD2.4 and a diode VD9.

When the mains voltage goes beyond the set limits, the level at one of the DA1 outputs will become high. Entering through VD5 or VD6 on the pin. 9 of the counter-divider of the DD1 microcircuit, it prohibits the operation of the counter, at the output M of which a low level will be set. As a result, the pulses from the output of the element DD2.1 do not pass to the output DD2.2. The triac, the control electrode of which does not receive opening pulses, is closed and the refrigerator is de-energized. Transistor VT2 is open, the LED is on and indicates blocking. When the mains voltage returns to normal, a low level will be set at both outputs of the op-amp. Since C5 is discharged, the output level of DD2.4 is also low. A high level at the output M allows the passage of pulses with a frequency of 2.12 kHz through DD2.2. Amplified by the transistor VT3, the pulses open the triac. The refrigerator is running but the LED is off.

Machine details refrigerator protectionassembled on a printed circuit board.

To set the operating thresholds, instead of an autotransformer, you can use any 100 W mains and ~ 30 V secondary. By connecting the secondary as in Figure A, we have 250 V at the output to set the upper limit.

Turning the secondary, as on B, we get 220 - 30 \u003d 190 V. We set the lower shutdown limit on them as follows. Submitting to the machinerefrigerator protectionalternating voltage 190 V, set the trimmer resistor R2 to the position corresponding to the limit of turning on the LED. Then, we apply a voltage of 250 V and repeat the setting by rotating the slider of the resistor R6. To adjust the current protection unit, you need a load that draws a current of 5 A.

This material will discuss how to protect refrigerators and compressor equipment from surges and drops in the mains.

To understand the essence of the issue, we will first consider the principle of operation of the refrigerator, we will analyze how jumps and drops in the supply voltage are dangerous for it, and consider several practical methods for solving this problem. So, everything is in order.

The refrigeration unit is a closed hydraulic system filled with a special coolant - refrigerant. Freons are used as a refrigerant in household refrigeration units, and ammonia is used in industrial ones.

Compressor, driven by an electric motor, pumps refrigerant through the entire system. Passing through different sections of the refrigeration unit, the refrigerant changes its state of aggregation, its temperature and pressure change.

Inside the refrigerator itself there is a special coil called evaporator. The refrigerant is supplied to the evaporator in a liquid state at low pressure and temperature. Without going into the complexity of thermodynamics and without building the heat balance equations, I will say that in the evaporator, heat is taken (i.e., heated) from warmer products, the walls of the refrigeration chamber. Through the walls of the evaporator, heat is transferred to the refrigerant and it begins to boil, since it is at a low temperature and under low pressure.

We all know the condenser well - this is a coil on the back wall of the refrigerator. Passing through the condenser, the refrigerant vapors give off their heat through the machines of the condenser to the surrounding room. The refrigerant cools and becomes liquid.

Next, the liquid refrigerant is pushed to pressure reducing valve. Passing through this valve, the pressure and temperature of the refrigerant decrease and it enters the evaporator again. Then the whole cycle repeats again.

We examined the hydraulic part of the refrigeration unit. We go further. The compressor is driven by an electric motor and is the most vulnerable and expensive link in the refrigeration plant.

Why are surges and voltage drops in the mains so dangerous for compressor equipment?

For all equipment with electric motors, low voltage is dangerous. With a low voltage, when trying to start and reach the rated speed, the electric motor will work with high starting currents, which can lead to its breakdown.

But in this article I want to consider a different problem.

The quality of our electrical networks leaves much to be desired. To protect against possible surges and voltage drops in the supply network, it is very desirable to use. When the voltage goes beyond the permissible range, such a relay disconnects consumers from the external network until the voltage returns to the permissible limits.

So, in many instructions for refrigerators it is written that after disconnecting the refrigerator from the mains supply, reconnect it no earlier than after 5, and preferably after 10 minutes. Those. immediately after turning off the refrigerator without a time delay of at least 5 minutes, it is impossible to connect it again to the mains! Let's see why.

This requirement is due to the inertia of the system. At the moment the compressor is disconnected from the mains, high pressure remains in the discharge path, because the compressor sucks in the refrigerant, compresses it and pumps it to the condenser. This high pressure is stored inside the compressor chamber and continues to put pressure on its piston.

In household refrigeration units, piston-type compressors are used, their design is similar to the internal combustion engine of a car. The compressor motor rotates the crank, which in turn drives the piston.

So, the excess pressure from the refrigerant on the compressor piston creates a lot of resistance, a lot of effort to start the motor shaft. If at this moment you try to reconnect the refrigeration unit to the mains, then in this case several options are possible.

- The electric motor will start, but with a large resistance on the shaft and with an increased starting current.

- The protection will constantly work and constantly try to start the compressor.

- The motor will fail.

As you can see, all these factors significantly reduce the durability of the unit, or lead to its failure.

The compressor restart delay is needed to ensure that the refrigerant pressure in all components of the chiller hydraulic system equalizes. This will make restarting the compressor easier. This takes at least 5 minutes.

In order to implement a refrigeration compressor restart delay, three circuit designs can be used.

Voltage control relay

One common voltage relay is used, installed for all consumers, for the entire apartment. Such a relay must be capable of setting a turn-on delay of at least 5 minutes. This delay is provided by the DigiTOP and ZUBR voltage relays. The latter can have a delay of up to 600 seconds (10 minutes).

The disadvantage of such a solution is obvious - during power surges, power supply in the entire apartment will appear only after a delay time. And if the voltage drops are regular, then this is very inconvenient.

Group voltage monitoring relays

To get rid of the shortcomings of the previous method, several voltage control relays are used. I have already examined schemes with in detail, what they are used for and how they work. To solve our problem, we can use one of the voltage relays to protect a group with compressor equipment - refrigerators, freezers, air conditioners. When the supply voltage is restored, the group with refrigeration equipment will be connected to the mains after the time delay has elapsed. At the same time, all other consumers of the home electrical network can be connected much earlier. It is very comfortable. In addition, you can set your own settings for the voltage relay of the refrigeration group.

When connecting a circuit with several voltage relays, it is convenient to use. The disadvantage of this method is the high cost and the need for additional space in the .

Time relay with on-delay

The third option is to use with a turn-on delay. To organize a compressor restart delay, a time relay is installed after the automatic switch of the compressor group, which closes its contacts after a certain time, after power is supplied to its winding.

Such a relay should provide a delay setting of at least 5 minutes, and preferably more. It is also necessary to pay attention when choosing a time relay to the maximum switched current by them, and to the current consumption of the protected refrigeration unit.

The advantage of this method is saving space in the electrical panel, sometimes lower cost, compared to a voltage relay.

These three approaches are used to protect compressor equipment from surges and voltage drops in the supply network. It is not difficult to implement them schematically. Difficulties can arise with a large number of refrigeration equipment, or when using. In this case, you can always write to me in feedback and order a circuit or electrical panel assembly. Contacts are at the bottom of the site.

See detailed video

Protection of the refrigerator from power surges and surges

When you buy a new household appliance, the seller will usually try to sell you some additional accessories for it. One such dopov is the voltage stabilizer. And if, for example, this device is completely useless for TVs (at least for modern TVs), then for a refrigerator, a stabilizer is a completely appropriate purchase. However, you should buy it only if certain conditions are met. Let's dwell on this moment in a little more detail.

Do I need a voltage stabilizer for the refrigerator or is a surge protector enough?

It all depends on how much the voltage in your network differs from the nominal value. According to clause 4.2.2 of GOST 32144-2013, the permissible deviation is 10%, i.e. normal voltage in the outlet is considered to be voltage in the range of 198-242 V. Any household appliances, including all refrigerators, are designed for long-term operation at such voltages.

But what if the voltage in your house jumps a lot and periodically goes beyond the permissible range? For example, you live in a dacha, and your left neighbor saws something on a circular saw at night, and your right neighbor has been making a fence for five years? Or maybe your power lines still remember the young Brezhnev? Or is your cottage powered by a Tsarist-era diesel generator? In all these cases, the voltage at the outlet can drop to very low (150 V and below) or, even worse, rise to dangerously high values ​​​​(260+).

You can notice such voltage drops by observing the brightness of the glow of incandescent lamps. The most pedantic can use the simplest pointer voltmeter (a digital multimeter is not suitable for this purpose, since it is difficult to track fast voltage surges with it).

undervoltage

So, if the voltage in the network is greatly underestimated, then it may not be enough to start the compressor engine. In some circuits, current will continue to flow through the windings of an idle motor, eventually causing it to overheat and fail.

If the engine still starts and runs, then at a reduced voltage, more current will flow through the motor windings to provide the same power, which also leads to excessive overheating of the engine and its breakdown.

Of course, a responsible manufacturer has foreseen such a scenario and therefore a thermal relay is always built into high-quality refrigerators, which should de-energize the entire circuit in case of overheating. But this mode of operation is an emergency and it is desirable to avoid it in every possible way.

overvoltage

No less dangerous and high voltage. In the simplest circuits, there is a direct dependence of the compressor motor power on the supply voltage. With increased voltage, the engine starts to work in excess of its rated power and its resource is noticeably reduced.

In addition, high voltage can lead to interturn breakdown in the rotor / stator winding, as well as damage the electronics.

Thus, if the voltage in your network is unstable and you do not want to risk an expensive refrigerator, buying a stabilizer will be the right decision. The cost of the stabilizer is not too high, but it will provide round-the-clock protection against low and high voltage.

By the way, refrigerators with an inverter type motor are even more demanding to all supply voltages.

High voltage interference

If everything is in order with the voltage in the outlet, this does not mean that nothing threatens your refrigerator. A great danger for the electronic filling of refrigerators (however, like any other household appliances) are short-term high-voltage interference. The duration of such power surges is very short (milliseconds), so they do not cause flashes of chandeliers and other lamps (the tungsten filament is too inertial to have time to react). However, even one such impulse may be more than enough to burn the electronics in your refrigerator.

Such interference occurs for various reasons - it can be a close discharge of linear lightning, ball lightning hitting power lines, emergency situations at the electricity supplier, switching of some powerful inductive load, etc. Even the burnout of an ordinary incandescent lamp causes a high voltage pulse in the electrical network due to the occurrence of self-induction EMF.

But in fact, everything is not so scary. All self-respecting manufacturers always build filters from RF and impulse noise into their equipment. Especially if it is some kind of equipment that is sensitive to interference - amplifiers, computers, televisions. It is clear that it would never occur to anyone to build filters into some kind of iron or soldering iron.

An additional protection against high-voltage impulse noise is provided by a mains filter. Only it should be exactly a surge protector, and not a simple extension cord on which the Chinese wrote that it was a “power surge protector”. A real device cannot cost less than a thousand rubles. Inside there must be a board with a circuit, with chokes, capacitors and varistors, it is imperative that there is a ground contact on the plug and in all sockets. There is no point in buying a surge protector if you have already bought a regulator (because each regulator contains input voltage filtering circuits by default).

So let's recap the above. If the voltage in the outlet jumps a lot, then it is advisable to use a stabilizer to connect the refrigerator. If the voltage in the network is quite stable and does not deviate too much from 220V, then it is not advisable to buy a stabilizer. To protect the delicate and sensitive electronic circuits of the refrigerator from high-voltage impulse noise, you can use a high-quality (expensive) surge protector.

Perhaps it would be appropriate to recall here that Samsung produces refrigerators with an intelligent Volt Control system. In fact, these are refrigerators with their own built-in voltage regulator.

Which voltage stabilizer to choose for the refrigerator?

You need to choose a stabilizer based on your requirements - refrigerator power, low or high mains voltage, etc. You can, of course, buy an expensive device that is guaranteed to suit anyone, but why overpay?

You can immediately tell what you need only single phase stabilizer. Three-phase are used to power industrial refrigeration equipment and this is clearly not your case.

The remaining characteristics should be considered in more detail. So, what kind of stabilizer is needed for a refrigerator? Let's go in order.

Power

The most important characteristic that you need to pay attention to when choosing a stabilizer is maximum load power which can be connected to it. In our case, it corresponds to the starting power of the refrigerator, and is measured in volt-amps (VA).

It is necessary to distinguish between the rated power consumption and the maximum (peak, starting, starting).

The fact is that the engine in the refrigerator compressor (washing machine, air conditioner, fecal pump, etc.) consumes significant currents at the time of startup and until it reaches operating speed. These are the so-called starting or starting currents. Any stabilizer is a low-inertia device that quickly responds to any changes both in the input circuit and in the load. Therefore, if a significant power reserve is not provided, the stabilizer will go into overload protection at the moment the compressor is turned on.

So what power stabilizer is needed for a refrigerator?

Peak power consumption can be taken as 5 times the rated power, which is given in the instruction manual (it can also be found on a sticker on the back of the refrigerator). If these values ​​cannot be found, then we can roughly assume that the rated power consumption for a single-chamber refrigerator usually lies in the range of 150-200 W, and for a two-chamber refrigerator - 200-400 W.

It should also be taken into account that the maximum output power of the stabilizer is always indicated for normal operation, i.e. when the mains voltage is 220 volts. With lower voltage, the maximum output power threshold will also decrease. From this it follows that when choosing a stabilizer, you need to build on the maximum power of your refrigerator, plus another 20% margin on top. Then the power will be enough to power the refrigerator both at low and at high voltage.

Thus, with the main characteristic of the stabilizer, power, we have decided. In short: we take a stabilizer 20% more powerful than the maximum power consumption of the refrigerator. For example, if you have an ATLANT M 7184-003 with an average power consumption of 120 W, then you need to choose a stabilizer with an output power greater than:

P st. = 120 W ⋅ 5 + 120 W ⋅ 5 ⋅ 0.2 = 720 W

The minimum required voltage stabilizer power for refrigerators (for the most common models) is shown in the table:

refrigerator model	Number of cameras	Compressor power	Required stabilizer power
Saratov 264	2	135 W	670 W
Indesit NBS 20AA	2	200 W	1000 W
Saratov 213	2	140 W	700 W
Indesit DF 5180	2	190 W	950 W
LG GA-B409UEQA	2	210 W	1150 W
Ariston HF 4200	2	190 W	950 W
Biryusa 129	2	130 W	720 W
LG GA 499	2	170 W	680 W
Liebherr CBNes 3857	2	189 W	1300 W

Working range

The next important characteristic of the stabilizer is input voltage range. It’s hard to make a mistake here - the wider this range, the better. There are models designed to operate from 70 to 330 volts. However, the typical range of the most common models is 100…260V or 120…300V. See for yourself what is best for your network.

Performance

A good regulator should have sufficient response speed for changes in input voltage. This is the only way to protect the delicate electronics of the refrigerator controller. But, pay attention, the speed should be exactly sufficient (in practice it is 10-20 ms). There is no point in chasing ultra-high performance, no matter what marketers tell you. Acceptable response time is provided by all modern stabilizers, with the exception of old electromechanical models (working on the LATR principle).

To help you understand what speeds we are talking about, remember that only one period of mains voltage (50 Hz or 1/50 s) fits into 20 milliseconds. And since the electronic control unit of the refrigerator is powered through capacitive filters, the circuit does not even have time to notice the power surge. Not to mention getting out of order.

Reliability and security

Since any refrigerator works around the clock, the stabilizer must have increased reliability. You should not buy frank Chinese, even despite its low cost. The problem with cheap models is that they do not pass any certification and do not provide the declared characteristics. No one will give you a guarantee, for example, that the output power of the stabilizer corresponds to what is indicated on the label.

In addition, in pursuit of cheapness, the manufacturer does not complete its devices with even elementary steps of protection against overvoltage, overload, overheating. And this is already unsafe and can lead not only to the failure of an expensive refrigerator, but also to electric shock or fire.

About such characteristics as output power at the borders of the declared range and stabilization speed, you can not mention at all. The Chinese spit on this from a high bell tower, because. they know perfectly well that it is possible to reveal such shortcomings only with the help of tests that are inaccessible to the average consumer.

Therefore, my advice to you, do not be fooled by cheapness, do not create problems for yourself. Here are reliable and time-tested manufacturers of stabilizers:

• Progress (LLC Energia, Pskov);
• Calm (CJSC Tensi-Techno, Tula);
• SSK ("Energy Technologies", Moscow)
• Lider (NPP INTEPS LLC, Pskov)
• RUCELF (Kodis LLC, Dnepropetrovsk)

The final decision on which voltage stabilizer for the refrigerator is better can be made based on the feedback from the owners. Below is a list of very good models designed for wallets of different thicknesses.

Price

All stabilizers that meet the declared characteristics and have quality certificates have a rather high price - from 6,000 rubles and much higher (up to several tens of thousands of rubles, depending on power). The table shows the most popular models of the current year:

If the purchase of such devices is beyond your power, you will have to lower the bar and look at Chinese-made equipment. But here it is necessary to approach the choice very carefully. Here is a list of Chinese who, judging by the reviews, have proven themselves very well in the Russian market:

All listed single-phase stabilizers have a wire with a plug and output sockets. Connecting the refrigerator through the stabilizer is very simple - plug the refrigerator plug into the socket on the stabilizer body and turn on the device.

Units up to 2kW do not have fans, as they only need natural air circulation through the vents in the case. Therefore, the only noise they make is the switching of power relays. Stabilizers with electronic stabilization (on thyristors) operate completely silently.

Poorly assembled stabilizers can hum like old Soviet transformers.

Depending on the version of the device, they are placed next to the refrigerator either on the floor or on the wall. Can be placed directly on the refrigerator. All small power stabilizers are quite compact and do not take up much space.

Conclusion

For those who have no time to delve into, let's summarize briefly:

1. A stabilizer for a refrigerator is needed only if the mains voltage deviates by more than 10% from the value of 220 volts.
2. For household refrigerators, a single-phase stabilizer is needed.
3. The power of the stabilizer should be at least slightly higher than the maximum power of the refrigerator.
4. Any type of stabilizer is suitable, except for electromechanical ones. The latter have an insufficiently high response time.
5. To ensure high reliability, you should purchase certified models from trusted manufacturers. But they are expensive.