Voltage stabilizer for a gas boiler - is it worth buying it and what to choose?

A voltage stabilizer is a device designed to maintain the output voltage within a narrow limit that complies with standards, regardless of the input voltage parameters. In simple words, the stabilizer passes through itself the incoming voltage from the household electrical network and produces at the output the voltage required for normal operation of the gas boiler, close to 220 or 230 V with a smooth sinusoid with a frequency of 50 Hz. However, for a gas boiler, voltage stabilizers are not always justified.

Does the boiler need a stabilizer?

On forums, in topics where a voltage stabilizer for a gas boiler is discussed, there are directly opposite opinions:

1. A stabilizer is not needed; the boiler works perfectly without it throughout its entire service life.
2. The boiler must be connected through a stabilizer, otherwise the likelihood of its failure is very high.

Both points of view are supported by facts.

The operating instructions for absolutely all boilers do not specify special requirements for the supply voltage. They say that the equipment is connected to a household network of 230 (240, depending on the country of origin) V, 50 Hz. Additional conditions, such as permissible deviations in voltage and frequency, the content of higher harmonics (non-sinusoidal voltage) are not specified.

Nowadays there is quite a large selection of stabilizers in stores.

In general, this means that the built-in power supply of the electronic unit provides the required supply voltage for the circuit at a mains voltage that complies with the standard. At the same time, the normal operation of other electrical equipment included in the boiler installation is guaranteed, in particular, the pump that creates excess pressure for forced circulation of the coolant.

The European standard establishes a nominal network voltage of 230 V with a tolerance of +/- 5% for a long time and +/- 10% for a short time. Those. the system will operate without failures and failure of components in the network voltage range of 207-253V.

At the moment, the Russian mains voltage standard is consistent with the European one, the nominal value is 230V, and permissible deviations are no more than 10% in any direction.

At the same time, manufacturers do not consider failure of boiler equipment due to mains voltage deviations greater than those established by the standard as a warranty case. Accordingly, if sags or overvoltages in the network exceed the permitted limits (the voltage drops below 207V or rises above 253V), stabilization becomes necessary.

Many manufacturers of heating equipment may refuse a warranty without a voltage stabilizer in the heating system.

Thus, the user must make a decision about purchasing a stabilizer based on his own network stability data. Of course, in case of deviation from the standard, it is possible to file claims against the electricity provider, including in court, but this process is lengthy and will not help protect the boiler from failure.

Expert opinion

Grebnev Vadim Savelievich

Heating system installer

Some boiler manufacturers indicate permissible supply voltage deviations in the operating documentation. As a rule, this is done by companies whose products allow operation under sags/overvoltages greater than standard ones.

The best known manufacturers and models: characteristics and prices

All the models below will fit exactly any standard gas boiler. When forming their list, we followed the order from the least quality, in our opinion, to the best on the market.

Huter 400GS

Type: relay Power: 350 W Input voltage: 110-260 V Accuracy: 8% Response time: 7 ms Output: 2 Euro sockets

According to the origin of the brand, the stabilizer is German, but it is produced and assembled, like most modern equipment, in China. It has a fairly wide range of input voltage and fast response, but in practice already at 160-170 V it loses up to 30% of the rated power, so it is better to use it in a network with not so serious deviations. A nice plus is the presence of two sockets at once, qualitatively and conveniently mounted in the case, which in turn is metal and has a pleasant appearance.

Typically, the stabilizer performs its functions without problems and has been in operation for more than 8 years. However, during this time, there were also negative operating experiences when the device began to exceed the permissible error or switched off completely, turning off the boiler along with it. In most cases, the stabilizer works well, but there are still cases of malfunctions, which is why we rightly ranked it in last place.

BASTION Teplocom ST-555-I

Type: relay Power: 300 W (400 VA) Input voltage: 165-260 V Accuracy: 8% Response time: 20 ms Output: 1 Euro socket

Not very expensive, but also not the best Russian-made stabilizer in terms of price-quality ratio. It can be classified as the most simple and inexpensive device, but with a price that is not the most competitive in this category. The device performs its functions perfectly, has an acceptable input voltage range, and not the best, but sufficient for almost any gas boiler, response and error indicators. According to reviews from owners, it performs its functions perfectly; no serious technical problems are known for more than 5 years of operation.

An excellent bonus is the ability to withstand higher loads of up to 555 VA (about 416 W) for 15 minutes, which will allow the boiler to start normally, even if the standard active power was not enough.

However, the disadvantages, in addition to the high cost for this category of stabilizers, are its mediocre build quality, a simple device, a very ordinary fuse, and an inconveniently placed socket on a separate output cable. Well, and the clicks characteristic of all relay devices.

Powerman AVS 1000 D Black

Type: relay Power: 500 W (1000 VA) Input voltage: 140-260 V Accuracy: 8% Response time: 5-7 ms Output: 2 Euro sockets

A better, more functional and confidence-inspiring stabilizer with average performance. Firstly, unlike previous models, it looks good and neat inside, it uses a modern troidal transformer, the relays have a large power reserve, the board is full-fledged, without jumpers.

Secondly, it has wider functionality. An important feature is protection against overload or voltage drop below the limit, as a result of which the device not only turns off the load without harm to itself and connected devices, but also automatically restores power when the network parameters are normalized. One of the nice bonuses is the presence of good filters that do not eliminate, but significantly reduce the level of pulsed and high-frequency interference. There were no service complaints regarding operating practices; the device reliably performs its functions.

The only drawbacks are the floor mounting method, which is not always convenient, especially in the case of a wall-mounted boiler, and the clicks that are characteristic of all relay models, although in this case they are subjectively quieter.

RUCELF BOILER-400

Type: relay Power: 400 W Input voltage: 150-250 V Accuracy: 8% Response time: 10 ms Output: 1 Euro socket

Already a more well-known and widespread voltage stabilizer made in Russia. And although some experts claim assembly in China, according to official information, production is located in the Moscow region (Kolomna), and there is no other confirmed data. Regardless of the country, the inside of the device is neat, well laid out and assembled, there are no empty spaces or jumpers on the electronic board, and the relays operate relatively quietly.

There is overvoltage protection (although it does not start the boiler on its own), protection against short circuits, thunderstorms and lightning. There are no cases of malfunction known from operating practice; the manufacturer states that the device was tested on a huge number of single-circuit and double-circuit models from various manufacturers: Baxi, Ferroli, Buderus, Vaillant, AEG, Protherm, Viessmann, Bosch. Indeed, in addition to the technical passport, you can find real letters of recommendation from most of the listed manufacturers.

The only drawback is a strong reduction in power even at a voltage of 170 V and below (by 25% or more), but even half the power of the model is enough for the normal start-up and operation of most gas boilers.

Dependence of the input power of RUCELF BOILER-400 on the network voltage.

To be sure, you can take the 600 W version, which is only 500 rubles more expensive.

Energy APC 500

Type: relay Power: 350 W (500 VA) Input voltage: 85-270 V Accuracy: 4% Response time: 10 ms Output: 2 sockets type “CEE 7/5” (see below)

A well-known and proven stabilizer with very good technical characteristics, quality and functionality. It is distinguished by a very wide operating voltage range; in extreme situations it is capable of maintaining a voltage of 75 V, of course, with a serious loss of rated power. It is also capable of withstanding up to 150% power overload for a short period of time.

Inside, everything looks complete and neat; the assembly and materials of the case/buttons/sockets are also pleasant for a device in this price category. Regarding practice, this is a well-known and one of the most common, problem-free models. It is worth special mentioning the almost silent operation, despite the relay.

If the operating limits are exceeded, the device turns off the load, after which it restores operation of the equipment in automatic mode. There is filtering against high-frequency and impulse noise, and short-circuit protection.

Of special note are 2 sockets of the “CEE 7/5” type, which require the presence of an additional grounding pin. Thus, you will never confuse the “phase/zero” polarity in the case of a phase-dependent boiler, which may otherwise simply not turn on. However, you should not be afraid of such sockets; on almost all boilers, the plugs are equipped with an input for a grounding pin; the situation is similar even with the simplest surge protectors.

Shtil InStab IS550

Type: inverter (double conversion, on-line) Power: 400 W (550 VA) Input voltage : 90-310 V Accuracy: 2% Response time: 0 ms (no delay) Output: 1 Euro socket

One of the best and most popular voltage stabilizers for a gas boiler. The ability to operate over such a wide input voltage range is truly rare. Plus, we have all the advantages of the inverter type: the absence of moving parts, which means silent and more durable operation (with the exception of more powerful models with cooling fans), a perfectly clean and smooth sine wave at the output, absolutely independent of the parameters of the electrical network, no delays in response, compact sizes.

A special feature is a built-in network filter that removes distortion at the output and does not let it pass into the primary network; there is full filtering of interference that removes it, and not just reduces the level. There is also electronic protection of the load and the stabilizer itself from short circuit, overload, low and high input voltage, and overheating. There were no service cases due to operating practices. But that’s why it’s an inverter stabilizer; for a device of this type, such characteristics and reliability are the norm.

By the way, the model has many certificates from the State Standard of the Russian Federation, the Ministry of Information and Communications of the Russian Federation, the Customs Union, and is used not only for domestic needs, but also in the commercial sector, and has become widespread thanks to this. The only significant drawback is the price.

Ferro-resonant stabilizers

Ferro-resonant devices have been well known in Russia since the times of the USSR. It was according to this scheme that the first stabilizers produced by the domestic industry were built.

The circuit of such a stabilizer will include 2 windings located on a common core - primary and secondary. Moreover, the section of the magnetic circuit with the primary winding is not saturated, but with the secondary winding it is in saturation mode due to the smaller cross-section.

As a result, as voltage changes on the primary winding increase, the magnetic flux through the secondary winding remains practically unchanged, which ensures stabilization of the output voltage. The excess flux of the primary winding is closed through a magnetic shunt.

Thus, the stabilizer circuit:

• It is as simple as possible, does not have complex electronic components, which ensures high reliability and durability.
• Provides high accuracy in stabilizing the output voltage and maintaining a sinusoidal shape over a wide range of deviations (although distortion of the output voltage shape is not excluded).

• Easily tolerates most external influences, including fairly high humidity and temperature, and their changes.
• There are no delays in regulation in case of supply voltage deviations.

The advantages of the scheme are confirmed by the fact that most devices produced in the 50-60s of the last century retain their functionality and characteristics today.

However, such stabilizers also have some disadvantages, due to which they are now rarely used:

• 
  Considerable weight and dimensions.

• Low efficiency and, as a result, the release of a large amount of heat on the circuit elements.
• Noisy operation, typical for all devices with powerful winding units designed for mains voltage.
• Unstable operation in current overload and idle modes.
• A fairly narrow range of input voltage deviations within which stabilization is possible.

All this led to the widespread replacement of ferro-resonant ones with more modern analogues.

Why should a stabilizer become a mandatory element of the system?

Unfortunately, not all owners of autonomous heating systems with modern gas equipment fully understand how important a stabilizer is. Very often you can come across opinions that “I have had a gas boiler for 20 years, and I have managed quite well without any electronics and without a stabilizer”, “we never have voltage drops”, or “just think, the electronics will not work for some time control - this will not affect the overall performance of the system.”

All these and similar opinions are deeply erroneous, and even vicious. Let's figure it out.

A. Those who support “working the old fashioned way” have the easiest answer. Rejecting advances in technological development is not the smartest position. Perhaps this is because many simply do not even imagine what conveniences modern automated gas boilers provide, and this is somewhat different from what they are “used to”.

Control panels of modern gas heating equipment with programming capabilities for operating modes

• Not only is the movement of the coolant ensured by a circulation pump (or a cascade of pumps). Special options provide a post-circulation mode, when, after turning off the boiler burners, the pumps continue to operate for a certain time, ensuring the most uniform heat distribution, avoiding zones with contrasting temperature levels.
• If boilers of the old design were “sharpened” to turn on all burners simultaneously, then the flame modulation functions allow you to start only the required number of them, while simultaneously adjusting the combustion intensity (the height of the flames).
• Frequent restarts of the boiler are not very useful for it, and this “flaw” is successfully dealt with by the functions of smooth ignition and reducing the intensity of gas combustion when approaching the upper threshold for heating the coolant set by the user. The system begins to work much smoother and more economically.
• Modern boilers can provide heat to several heating circuits that are different in principle and temperature. Moreover, settings for each of the circuits can be set individually. Moreover, the possibility of programming allows you to enter a weekly operating mode, with gradation according to entrance and working days - the system will maintain the optimal temperature in the rooms only when it is really required, and reduce the heating intensity for the period when there are people in the apartment (house) not expected.
• More “advanced” boilers are equipped with microprocessor systems that are capable of assessing external conditions (temperature indoors and outdoors), analyzing the relationship between them and launching the most favorable algorithm for the overall functioning of autonomous heating for current conditions.
• Finally, any modern gas equipment constantly monitors the level of safety of its operation. And this applies to many aspects. Of course, the protection system will work if the burner accidentally goes out, if there is insufficient draft in the chimney, if there is low gas pressure in the supply line, or if there is a leak (pressure drop) in the heating circuit. In addition, a special function will never allow the system to freeze (it will always maintain a positive temperature), and many boilers also monitor the condition of the electromechanical part - even during long periods of downtime, to prevent souring, valves and bypass valves will be switched, and circulation pumps will be briefly started .

Comfortable? - Undoubtedly! Is this functionality worth installing a voltage stabilizer? – Probably the answer is obvious!

B. The statement that “we never have voltage surges” does not stand up to any criticism at all. It is a typical example of illogicalism - “never happened before” does not mean “never and will never happen in the future.” The trouble is that this phenomenon does not always depend only on the human factor - natural causes can also intervene. Judge for yourself:

• Even the most reliable power lines cannot be absolutely insured against natural disasters. “Ice rains”, falling old trees, hurricane gusts of wind, seismic phenomena - all this can cause wire breaks, accompanied by either a voltage drop, or, even worse, a phase imbalance with such jumps that can instantly damage electronics.

Broken power line wires are a fairly common occurrence during “ice rains”

• The development of the power transmission line network often simply does not keep up with the growing number of energy consumers, especially against the backdrop of the modern construction boom. Newly emerging suburban settlements, and sometimes production facilities, can be connected to a stable power transmission line, and never before seen problems may arise during peak consumption hours.
• And, of course, the notorious human factor - the consequences of the work of unqualified “specialists”, or even a neighbor who imagines himself an electrician, poor-quality installation or factory defects in the materials used and elements of in-house wiring, the phenomenon of vandalism that has not been eliminated to this day - are quite possible reasons the appearance of instability in a previously seemingly flawless power line.

V. And the third objection: they say, temporary changes are nothing to worry about. That's how to say it. Of course, any electrical household appliance has a certain operational reserve - a voltage range within which voltage surges will not cause any inconvenience. But if the jumps are significant, then everything can end in improper operation of the equipment - insufficient pressure in the circuits, lack of air in the combustion chamber during its forced supply, imbalance of the system, and in unfavorable circumstances - a serious accident, failure of the electronics, with the need for further carrying out expensive repairs (and this is still at best).

Burnt electronic boiler boards - possible consequences of strong power surges

Particularly dangerous in such cases are breaks in the “zero” wire in a three-phase line, which are usually used to connect multi-story buildings with a large number of subscribers. As can be seen from the diagram shown below, in this case the effect of opposing phases occurs with a wild voltage surge and with virtually guaranteed failure of the electronics, and sometimes ends in more serious accidents, on the verge of a fire hazard.

A break in the neutral wire in a three-phase network can cause very sad consequences.

Since most modern voltage stabilizers are equipped with functions for complete emergency power shutdown in case of voltage drops exceeding the stabilizing capabilities of the device, such consequences can be completely avoided.

Conclusion - it will be much cheaper to spend once on a stabilizer (the price of which cannot be compared with the cost of a modern gas boiler), and be calm about the safety of your equipment.

We hope that we managed to convince the skeptics, so we move on to a closer look at voltage stabilizers.

You may be interested in information about how gas heating boilers are designed, wall-mounted double-circuit prices, reviews

Electromechanical stabilizers

The main component of electromechanical stabilizer circuits is an autotransformer - a device that allows you to change the transformation ratio. This is achieved by moving a current-collecting element - roller, slider or brush type - along the transformer winding.

The contact is moved by a servo drive, which is controlled by an electronic circuit that measures the input voltage and compares it with the set value at the output.

The advantages of this scheme include:

• Wide range of input voltage deviations.
• High accuracy of maintaining output voltage.

• The cost is lower than any stabilization devices on the market.

The main disadvantage of electromechanical stabilizers is the appearance of an electric arc (spark) during operation. It is caused by breaks in the current flow circuit when the moving contact moves along the turns of the transformer winding. Since the winding has significant inductance, interruption of the current causes an arc. Accordingly, it is prohibited to use such equipment in the same room as gas appliances!

Expert opinion

Grebnev Vadim Savelievich

Heating system installer

The problem can be solved by placing the stabilizer in another room and extending a separate line from its output to power the boiler.

However, such a solution can hardly be called rational, especially since the scheme has other disadvantages:

• The already mentioned breaks in the output voltage when the contact moves.
• Inertia associated with the response time of the servo drive, which does not allow you to quickly respond to changes in the input voltage.
• Significant mass and dimensions of the autotransformer.
• Insufficient reliability due to the presence of a moving unit.
• The need for frequent maintenance of the moving contact.

In short, when choosing a stabilizer for a boiler, it is recommended to exclude electromechanical devices from consideration.

How to choose a voltage stabilizer for a gas boiler: popular options and their technical review

Many modern gas boilers are a very complex “organism”, the highly efficient and stable operation of which in many modes is ensured by their “brain” - an electronic automatic monitoring and control unit and an associated system of solenoid valves and taps. In addition, a circulation pump may be provided in the boiler design itself, or installed in close proximity to it, ensuring the movement of coolant through the heating circuits. Well, gas boilers with a closed combustion chamber, in addition to this, also require the operation of fans that provide forced air supply for gas combustion and removal of combustion products through a coaxial chimney.

Voltage stabilizer for a gas boiler: how to choose

All these electromechanical and electronic units, modules and devices require stable power to operate correctly. However, it would be the height of frivolity to directly connect the boiler to a 220 volt household network. It’s no secret how different the voltage in it can be from the declared parameters, and such deviations, or even worse – sharp jumps in one direction or another, lead to instability of the equipment’s operation or even to its fatal failure. This means that you need a voltage stabilizer for a gas boiler; how to choose it will be discussed in this publication.

How necessary is a voltage stabilizer for a gas boiler?

There will certainly be skeptics who will question the very need to equip the boiler with a voltage stabilizer. Apparently, in the minds of such people, old models of heating equipment are still depicted, all automation of which was reduced to bimetallic heating sensors that turn off or open the gas supply to the burner as the coolant reaches certain temperature thresholds. However, a modern boiler is on a completely different level. The electronics of gas heating units opens up the broadest possibilities for ensuring maximum efficiency along with high efficiency and ensuring the safe operation of the equipment.

Control panels of modern gas boilers - rich in functional options, control and safety systems

• Stepwise regulation of heating levels is gradually being replaced by flame modulation - the automation itself determines the number of burners required at the current moment and the height of the flame in them.
• Modern boilers are equipped with a function of smooth ignition, reducing the combustion intensity when the last few degrees rise to the set level - all this reduces the number of equipment restarts and ensures extremely smooth operation.
• Post-circulation of the pump becomes a useful option - after turning off the burners, the coolant moves for a few more minutes to achieve even heating in all areas of the heating circuit.
• Modern electronic circuits are equipped with “artificial intelligence” - weather-dependent automation independently monitors current weather changes, analyzes the relationship between conditions outside and in the apartment, and develops the most optimal algorithm for the operation of the heating system. all this gives a significant effect of saving resources.
• Many boilers are designed to provide heat to several heating circuits with different temperatures. All these settings can be stored in the device’s memory with programming by days of the week and hours throughout the day - the most comfortable conditions will be created during those periods when they are really in demand.
• The automation of a modern boiler will never allow the water in the system to freeze during a long absence of the owners. Moreover, if the equipment has not been used for a certain period, the control unit will spontaneously give a command to switch the electromagnetic valves to several positions, to briefly start the circulation pump - so as not to create sticking, valve sticking, stagnation in the circuits, etc.
• And, of course, all modern boilers are saturated with safety levels designed to prevent the creation of emergency situations in the event of certain deviations from the norm - a drop in draft, pressure in the gas main or in heating circuits, in case of accidental attenuation and in other abnormal cases.

However, all this rich and useful functionality becomes available only with a stable power supply.

Of course, any modern equipment is capable of operating in a certain input voltage range - this is indicated in the technical documentation of the product, for example: 220 ± 15%. But, unfortunately, even these limits do not guarantee the uninterrupted functioning of the automation - voltage drops can be much more significant. And it will be even more fortunate if such a difference only causes a temporary failure in the operation of the heating system (which, of course, is in itself extremely undesirable). It is much worse when an unstable input voltage leads to burnout of electronic circuit elements, or even complete burnout of printed circuit boards. In this case, it is no longer possible to do without expensive repairs, and under certain unfavorable circumstances, even without a complete replacement of the equipment.

Possible consequences of changes in mains voltage - burnt-out boards of electronic control units for boilers

And all this often happens because the owners neglected to install an input voltage stabilizer.

We should not hope that, they say, there are no voltage drops in our house (village), or that they are so rare and insignificant that it is not worth purchasing additional equipment. This is a profound mistake, fraught with serious consequences. After all, the nature of voltage surges can be different, and no one is immune from such a “cataclysm.”

• The development or modernization of power lines often does not keep up with the level of consumption - the saturation of modern human life with electrical appliances is strikingly different from the indicators even ten years ago, and many power lines are much more “venerable” in age. There is no guarantee that in a year or two the power supply line, which today seems flawless, will cope just as well with the load that is increasing day by day.

Even the most reliable power lines are not completely immune to natural disasters.

• No one can foresee natural disasters. Hurricane winds, ice on the wires, falling trees and many other accidents - and then a wire breaks, accompanied by an instantaneous sharp phase imbalance and, accordingly, a voltage surge.
• The “human factor” can never be ruled out. Unskilled actions of some “craftsman” - a neighbor who independently climbed into the switchboard in the entrance, an error or negligence of an electrician, incompletely incorrectly installed in-house wiring, vandalism of individual “individuals” and other reasons - all this also gives a very high probability of a sharp power surge, which can be fatal to the boiler electronics.

In a word, if a prudent owner really wants to protect his equipment from unforeseen circumstances, he will definitely purchase a voltage stabilizer for a gas boiler, not paying attention to the skepticism of others or “good advisers”. And the only question is how to choose the optimal device that will ensure the uninterrupted operation of the equipment and the safety of its operation to the maximum extent.

Properly laid in-house electrical networks are a guarantee of safety!

Laying home or apartment electrical wiring does not tolerate negligence, disregard for existing norms and rules, or ill-considered decisions. How to properly organize electrical wiring in your home - read the special publication on our portal. And another article will tell you in detail about the optimal installation of an electrical distribution board .

Functions of voltage stabilizers, types and features of the device

The functions of the stabilizer for heating equipment are simple and clear. When the mains voltage changes within a certain range of its capabilities, the device must provide power to the equipment with characteristics that correspond to the standard or as close as possible to it. In the event that the surges or drops are so large that they go beyond the stabilizer’s inherent capabilities, its circuit must completely interrupt the power circuit until the input indicators return to the established range. This ensures the correct functioning of all equipment connected to the stabilizer and prevents its failure due to unacceptably large differences.

A wide range of devices of this principle of operation is presented to the attention of consumers, in a wide variety of designs and in a wide range of operational capabilities.

The range of voltage stabilizers offered for sale is very wide.

But if in most cases the emergency shutdown function of the device is handled by a device similar in action - a voltage safety relay - then the issue of voltage stabilization can be solved in different ways. Thus, stabilizers of electromechanical, relay and electronic principles of operation are distinguished.

• In electromechanical stabilizers, voltage equalization to the required level is performed by moving current-collecting carbon brushes along the circular winding of the autotransformer. The moving part is moved using a built-in servo drive.

Schematic diagram of an electromechanical voltage stabilizer
1 – turns of the autotransformer winding;

2 – current-collecting carbon brush;

3 – servo drive.

Such a scheme has proven itself well - it is distinguished by high stabilization accuracy (within ± 3%), and the price of such devices is in the category of the most affordable. However, electromechanical devices have a number of features that limit their use specifically with gas equipment.

The fact is that sparking can occur between the carbon brush and the current collector of the autotransformer, which especially increases as this unit wears out. And in the boiler room the use of electrical appliances that may cause sparking is strictly prohibited - simply for safety reasons. You can, of course, take the stabilizer into a residential area, but its operation is accompanied by audible noise, which not everyone will like. In addition, the performance of such a stabilizer still leaves much to be desired - the total response time to a voltage drop even reaches 2 seconds, which is too much for the sensitive electronics of a modern boiler.

In addition, such devices are not particularly durable - simply due to the presence of kinematics and friction units.

Conclusion - it makes sense to abandon the use of an electromechanical stabilizer in conjunction with a gas boiler or use it with special precautions.

voltage stabilizer for gas boiler

• Relay stabilizers are designed differently. Switching between the windings of the transformer, ensuring a change in voltage towards the norm, is done using relays - there can be from four to five to a dozen or more (the more, the higher the level of stabilization). There is no sparking of contacts in such devices - each cut is enclosed in a sealed housing.

Basic design of a small relay voltage stabilizer
1 – autotransformer winding terminals

2 – group of relays that provide switching between outputs.

Such devices, of course, have their drawbacks, and first of all these are stepwise adjustment and not very outstanding accuracy of the output voltage - usually in the range of ± 8%, which, however, is quite enough for most devices.

But relay stabilizers are distinguished by their speed of response to changes in the network, the ability to withstand power overloads, and a wide range of permissible input voltage. Such devices serve for a long time and trouble-free, and their price is low. A slight background noise from the actuation and switching of the relay can be considered a conditional disadvantage, but in a boiler room environment this is unlikely to be significant.

Currently, relay stabilizers are among the most popular among consumers.

• A big step forward was the emergence of purely electronic stabilizers. In them, the role of keys for switching between windings is performed by semiconductor elements - triacs or thyristors, which ensures the maximum speed of the prior, which is incomparable even with a relay circuit.

In electronic stabilizers, the role of keys is performed by semiconductor elements - thyristors or triacs.
The complete absence of “mechanics” not only speeds up the stabilization process, but also makes the device the most durable among all available varieties. The accuracy of stabilization directly depends on the number of control stages - there is an analogy with relay priors. Plus, electronic stabilizers are the most compact, absolutely silent, and unpretentious to external operating conditions.

Of course, a stabilizer of this type will be the best solution under any operating conditions - there are simply no significant shortcomings comparable in any way to other types. The only thing that can stop a potential buyer is the fairly high price of such products.

There are other types of stabilizers, including high-tech ones, with double inverter voltage conversion and almost perfect smooth equalization. However, for boiler equipment such devices are still seen as an excessive luxury.

How to choose the right voltage stabilizer for a gas boiler

Range of stabilizer capabilities

The first selection criterion is always the operating range of the stabilizer, that is, the upper and lower limits within which the device will be able to bring the voltage to a normal value.

The most reasonable decision would be to conduct a little “research” in your home or apartment before choosing and purchasing a stabilizer. It consists in tracing the dynamics of changes in the network voltage on different days and hours, during periods of peak morning and evening load, in a “quiet” night state, etc. Such monitoring will make it possible to more accurately determine the available range of differences, and the resulting picture will allow you to correctly select the desired stabilizer.

This is not at all difficult to do, but to take measurements you will need a multitester, a device that many good owners have. It’s inexpensive, and it won’t hurt anyone to have it in their “arsenal.”

Before taking measurements, it is necessary to correctly set the position of the multitester switch (voltmeter)

Before taking measurements, you must make sure that the switch is set to alternating voltage (on different devices this can be indicated by the symbols V~ or ACV , and the upper limit is about 600 or 750 Volts. It would be advisable to make a small sign, by day of the week and by hours, and take measurements, for example, at 6.00, 9.00, 14.00, 18.00, 21.00 and 24.00. A few days of such monitoring - and the whole picture of the dynamics of changes will be before your eyes, that is, the upper and lower limits of the range will be approximately determined immediately. All that remains is to expand these boundaries another 10÷15 volts in each direction to create a reserve, and the operating range of the stabilizer can be considered certain.

Availability of protection for extreme voltage drops, restart function

These are extremely important options that should not be forgotten, and which, unfortunately, may simply be missing on some low-price stabilizers.

The device must completely turn off the power circuit if the input voltages are outside the operating range - this way it preserves both itself and the equipment connected to it.

Even the infographics of this stabilizer show the possibilities of its automatic shutdown and restart

At the same time, the stabilizer must have a restart function. That is, in an emergency shutdown state, the automation monitors the input parameters, and when the network voltage returns to the permissible range of values, the device starts on its own, continuing to supply stabilized power to the boiler. Restart can occur with a certain delay set by the user - to eliminate frequent starts and shutdowns when balancing the voltage at the limit of the range.

The absence of such an option is undesirable - it is fraught with serious consequences. For example, during a long absence of the owners, a sharp drop occurred and the voltage stabilizer turned off. No matter how “smart” a gas boiler is, in the absence of a complete power supply, its automation will not be able to provide at least minimal heating of the heating system, and this may result in the system defrosting.

voltage stabilizer RUCELF

Current-voltage characteristics of the stabilizer

This parameter is often called the power of the stabilizer, and this, to a certain extent, is not meaningless, since it is also determined by the product of current and voltage. The difference is in the details, from the point of view of physics, and this parameter of the stabilizer speaks, rather, not about the useful power, but about the current parameters that it is capable of supporting.

True, the initial values ​​for determining the current-voltage characteristic are still the power, but only of the consumption devices connected to its circuit. In our case, this will be the boiler itself with its electronic circuit and, possibly, built-in fans, one or more circulation pumps (for example, if the heating system involves several circuits operating independently of each other) and possibly other system equipment, for example, automation collector and distribution nodes.

It would seem that everything is simple: you need to sum up the rated power values ​​of the connected devices - and get the desired result. In reality, things are somewhat more complicated. The fact is that many electrical appliances that have inductive coils consume additional power necessary to create operating conditions, for example, the same electromagnetic fields. This is usually expressed by the ratio:

Wп = Wн / cos φ

Where:

Wп – required total power;

Wн – rated useful power of the device;

c os φ – power factor, which is usually indicated in the passports of electrical appliances along with their rated power.

For devices with an electric drive, the value of the coefficient can be about 0.5 ÷ 0.75, that is, the value of the total power can exceed the nominal value by 1.3 ÷ 1.4 times. For circulation pumps and boilers with forced air supply and exhaust, it would not be a big mistake to focus on increasing the current-voltage characteristic by one and a half times compared to the rated power.

In addition, at the moment of startup of devices, high starting currents are always present, which can generally exceed the nominal value by 3–4 times, and this should also be taken into account.

There is one more nuance. When transforming voltage, an inevitable loss of power occurs - energy cannot be taken “from the sky”. There is a special transformation ratio that takes this phenomenon into account, and it depends on the input voltage level:

In order not to complicate the reader with independent calculations, below is a calculator that allows you to determine the required current-voltage characteristic of the voltage stabilizer with the required level of accuracy

Calculator for calculating the current-voltage characteristics of a voltage stabilizer for a gas boiler

Go to calculations

The calculation was made with the required power reserve already included.

Speed ​​of response and voltage stabilization

With this indicator, everything is clear - the faster the device’s electronics react to changes in input voltage and generate adequate signals, the better. It is usually measured in milliseconds (ms) and for high-quality devices it is only about 5 ms. However, a figure of 20 ms is quite acceptable. But if it is already higher, it’s worth thinking about, since the reaction is “weak.”

The data sheets of many stabilizers also indicate the speed of voltage equalization. It is already measured in volts per second (V/s, /s). A figure above 100 W/s is considered good - stabilization will occur almost instantly. If the speed is low, about 10÷20 V/s, then with large voltage drops the boiler electronics may not work correctly.

Additional equipment, design, dimensions of the device

A very convenient option of the stabilizer is a digital indication of the input and stabilized voltage - it is always possible to conduct visual control. However, whether it is worth overpaying for this, or just purchasing a device with a regular LED indication of operating modes is up to the owner to decide.

voltage stabilizer BASTION

Various display options: digital display, pointer voltmeters or simply LEDs indicating the operating mode of the device - the choice is up to the buyer

But device protection systems must be in place. This means protection against overheating, overload, and short circuit - the device must be able to “protect itself.” This is worth paying attention to.

Typically, the stabilizer parameters also indicate the operating temperature range. It is quite wide, and its lower limit, as a rule, is +5 ° C - a completely acceptable value for any boiler room. You should take its upper limit more seriously, since overheating of the stabilizer is certainly contraindicated. When installing the device, you should consider a place that would provide free circulation of air for cooling.

Stabilizers have approximately the same operational capabilities, but in wall and floor versions.

Installation of the device depends on its features. Wall stabilizers are very convenient - they can be placed near the boiler and they do not take up space at all. True, these are mainly devices of low or medium power, and are not always suitable in this parameter for specific conditions. Another option is a floor stabilizer, which can also be installed on a specially designated shelf. There are universal models that allow any installation method. The dimensions of the device must be taken into account when purchasing, based on the space allocated for it.

Manufacturer of the device, warranties provided

A very important selection criterion is always the reputation of the stabilizer manufacturer. But in this matter it is easier for consumers - this is the case when there is no need to look for any leading foreign brands - domestic devices of the brands “Energy” (“Voltron”), “Rucelf”, “Leader”, “Shtil” and some others no worse than imported “Quattro elementi”, “Resanta”, “Luxeon” or “IEK”.

The range of stabilizers from trusted companies on sale is very wide, and this makes it absolutely pointless to purchase any device unknown to anyone, even with a beautiful name and an attractive price. It is important to buy equipment of this type only in trusted stores (it is often offered by the same trade or service organizations that sell and install boiler equipment). You should carefully read the technical documentation of the device, clarify the terms of the service provided, and the manufacturer’s warranty period.

Brief overview of popular stabilizer models

And at the end of the publication - one more useful tip. If in local power grids the main problem is not so much fluctuations as interruptions in the voltage supply, then the stabilizer is unlikely to be a good helper. In this case, the best option is to purchase an uninterruptible power supply with built-in or plug-in batteries and, of course, an existing output voltage stabilization module. But this is already a topic for separate consideration.

Video: recommendations for choosing a voltage stabilizer for a gas boiler

Relay circuits

Relay circuits operate with an autotransformer or a multi-tap transformer in the primary and/or secondary winding. In this case, the relays act as switches that connect the necessary taps of the transformer so as to ensure a voltage at the output of the device that is as close as possible to the specified one.

In fact, this operating principle is reminiscent of electromechanical devices in which voltage stabilization is also carried out by changing the transformation ratio, but not by a moving contact, but by switching a key (relay contact group).

This made it possible to get rid of the main drawback of electromechanical stabilizers - sparking.

In addition, such devices have other advantages:

• 
  The speed of response to changes in input voltage, depending on the relay response time (ranges from 10-20 ms, which is comparable to the time of 0.5-1 cycles of the mains voltage).

• Simple and reliable control scheme.
• Significant mean time between failures, depending on the relays used.
• Maintainability and low cost of replacement components.
• Low sensitivity to current overloads.

The main disadvantages of the circuit are stepwise voltage regulation, which reduces the accuracy of stabilization and the complexity of the winding unit.

Semiconductor (thyristor and triac) circuits

Devices with semiconductor switches - thyristors and triacs - can be built according to two principles:

1. Similar to a relay circuit. The only difference is that semiconductor devices are used as a key rather than relay contacts.
2. Using a transformer at the input and regulating the output voltage by changing the opening angle of thyristors (triacs).

The first circuit is similar in characteristics to the relay circuit, but has higher performance. At the same time, to control semiconductor switches, a more complex circuit is required, and they themselves have a higher cost, lower overload capacity and less time between failures.

In a circuit with an AC voltage regulator, the transformation ratio remains unchanged. The effective voltage value is stabilized by controlling the moment of unlocking the keys. This approach makes it possible to simplify and reduce the cost of the winding unit and the structure as a whole.

However, this method of regulation has its own disadvantages, the main of which is the non-sinusoidal output voltage and the high level of interference induced into the network.

Expert opinion

Grebnev Vadim Savelievich

Heating system installer

Both variants of such schemes require cooling of the switches, the power losses on which are higher than on the relay. This affects the dimensions of the structure.

Availability of protection and restart function

Most stabilizers are equipped with a protection system. The main purpose of the system is to turn off equipment when unusual situations arise. This could be due to severe voltage drops at the input or overheating of the device.

The restart system is an extension of the protection system. After the protection is triggered and the equipment is turned off, the restart system monitors the parameters of the stabilizer and, when a stable state returns, restarts the device.

If there is no automatic restart, you will have to start the equipment manually. If the owners of the house are absent, turning off the device, and subsequently the boiler, can cause the heating system to defrost.

Two-link (inverter) stabilizers

Such circuits are built according to the structure - an uncontrolled rectifier with a filter - an inverter, usually with a transformer at the output to ensure stabilization during sags.

The circuit has maximum performance, provides high security in any mode, and guarantees accurate stabilization within a wide range of input voltage deviations.

Its main disadvantages:

• Complexity of the control system;
• High price.

In addition, depending on the chosen method of controlling the inverter keys, the output voltage may differ greatly from the sinusoidal one, which negatively affects the operation of the pump.

In general, an inverter circuit can be considered the best option for a boiler if its purchase fits into the owner’s budget.

Selecting a stabilizer based on boiler parameters

After choosing a stabilizer circuit, you need to decide on a specific model based on the electrical parameters of the boiler.

The only selection condition is power consumption. It can be found in the technical specifications of the boiler. The buyer is interested in the electrical power, and not the heat output from the boiler.

The stabilizer must provide the specified power with a margin of at least 25-30%. The reserve is taken from the calculation of the starting currents of the pump, which can exceed the rated value by several times. However, this process is short-lived and the indicated 25-30% is quite sufficient.

Expert opinion

Grebnev Vadim Savelievich

Heating system installer

Some manufacturers indicate in the documentation not the active power (in W), but the total power (in VA). To select a stabilizer, this value should be multiplied by a factor of 0.7.

Review of popular models

People often purchase expensive equipment that requires stabilized power supply. Electrical manufacturers are keeping up with buyers. Therefore, there are hundreds of models of voltage stabilizers for gas boilers on sale for every taste and pocket.

In order not to get confused in all this diversity, below is a brief overview of the popular models of these devices.

The voltage stabilizer ensures safe and reliable operation of the gas boiler. To choose a device, you need to focus on its type and operating principle. Some models of stabilizers are subject to premature wear from frequent switching and create extraneous noise.

It is equally important to take into account the technical characteristics of the connected equipment. The power of circulation pumps and their number have a direct impact on the choice of stabilizer model.

Often asked

Besides power, what should you consider when choosing a stabilizer?

Power is the only characteristic parameter. Otherwise, you should pay attention to the protection system and ergonomics of the device.

Does the distance between the boiler and the stabilizer matter?

Since the boiler power is small (as a rule, it does not exceed 500 W), the losses on the current-carrying conductors are negligible, therefore the stabilizer can be located at almost any distance from the boiler within an apartment or house.

Is it necessary to use a three-wire connection?

Many manufacturers stipulate this as a prerequisite.

What is better to use to power the boiler - a stabilizer or a UPS?

From the point of view of ensuring a stable supply voltage, these options are equivalent. However, the UPS will allow you to regularly turn off the boiler in the event of a power failure, unlike a stabilizer, which is not designed for such a mode. At the same time, most uninterruptible power supplies generate a rectangular voltage at the output, which is far from the best option for a pump.

What is a later stabilizer and can it be used for a boiler?

Lateral is another name for electromechanical stabilizers; its use in rooms with gas appliances is prohibited.

A stabilizer for a gas boiler will prevent equipment failure in the event of significant problems with the power supply network. To ensure maximum protection, the optimal circuit implementation and parameters should be selected.

Correct connection

For long-term operation of a gas boiler, proper connection is necessary. To regret 5-10 thousand and lose a boiler worth 100-200 thousand rubles, one cannot say that this is the right decision.

We can recommend installing a voltage control relay for the gas boiler immediately after the introductory circuit breaker. To eliminate interference, connect the boiler through a surge protector.

Gas boilers are mainly installed in rural areas and country houses. Electricity is supplied via a two-wire line. With this supply, a TT system is used for grounding. To prevent unforeseen situations, we recommend installing an RCD with a current of up to 30 mA.

When arranging the grounding of the boiler, it is recommended to use a separate circuit that is isolated from the rest of the network. To calculate the resistance, study clause 17.59 of the Electrical Installation Rules.