UPS for heating boilers. Uninterruptible power supplies for heating boilers of any type Uninterruptible power supply for heating boilers

Most modern heating boilers offered on the Russian market are volatile. The compact sizes of a copper, economy in operation attract more and more consumers. When installing such a boiler, you should immediately think about the uninterrupted power supply of the boiler. Many people miss this point. But none of us is immune from emergency situations in the power grid. Electricity can be turned off for a long time, and hence the power to the boiler. Which in winter can lead to complete defrosting of the heating circuit of the boiler. The cost of restoring the entire system, the boiler is huge. We recommend that you think in advance about the uninterrupted power supply of the gas boiler by installing special UPS for boilers .
There are two types of UPS for the boiler:

Uninterrupted power supply for backup type boilers

If there is a power supply in a certain voltage range (the range may vary depending on the manufacturer), it works directly from the network. In this mode, the shape of the output signal is fully consistent with the input. When the voltage goes beyond the specified range or the power goes out, it switches to battery operation mode, continuing to provide power to the boiler. Continuing to monitor the appearance of electricity. In this mode, the boiler is supplied with a voltage of 220 volts with a pure sinusoidal signal (the signal shape may be different, depending on the manufacturer and characteristics). There is a process of converting the direct voltage of 12 volts from the battery into an alternating voltage of 220 volts necessary for the boiler. If the battery voltage reaches the minimum critical discharge level, the UPS for the boiler is turned off. This saves battery life. When the mains appears, it switches to direct mode, simultaneously including charging the battery to 100% of the state. Therefore, this mode is called reserve, in the presence of the mains it is in reserve (reserve). And the work is included only in the absence or exit of the level beyond the operating limits.

Interactive UPS

They are also called online, always on. In general terms, such an uninterruptible power supply can also be called a stabilizer. Since even in the presence of a network, an alternating signal is converted into a constant voltage. The second stage is the reverse conversion of the DC voltage to AC 220 volts with a pure sine at the output, ideal for the boiler. In the event of a power outage, it runs on battery power. The input operating range of such uninterruptible power supplies is much wider. Able to smooth out surges, voltage dips. Removing various kinds of network interference, by building its own output sinusoidal signal of 220 volts, which is optimal for any boiler. They cost a little more, but the number of functions and protections performed justify this cost.

Most private houses are equipped with a modern heating system, including volatile boilers, elements for system circulation. But the state of our electrical networks, weather conditions cannot provide a stable power supply to the boiler. Take care in advance by installing an uninterruptible power supply to the boiler along with the circulation system. Installing an uninterrupted power supply system will save you from problems with the heating system in winter. When the boiler stops, it can lead to financial costs to restore the entire system. It remains to choose the right UPS for the boiler with a battery. Consider a few key points for the right choice.

Choosing the right UPS

The first step is to understand what a UPS is. The full name is an uninterruptible power supply. Some confuse this name with an inverter. It is not right. An inverter, as the name suggests, inverts voltages. In our case, it converts the direct voltage from the battery (battery) into an alternating voltage of 220V, with a frequency of 50Hz. Depending on the manufacturer, the output waveform can be pure sine (sine wave) or approximate (approximated sine). And this is its entire function. And the uninterruptible power supply includes an inverter function, a network and battery charge control function, a switchover function to the battery when the mains voltage fails, and a return when the network appears. Therefore, an uninterruptible power supply is called, which provides uninterrupted power, in a fully automatic mode.

Main characteristics for the right choice

We determine the voltage of the home network where the boiler is planned to be installed. It is enough to measure the voltage with a multimeter in the morning and in the evening. Why is this an important feature? Because UPS for offline type boilers operate in a certain range, allowed by Russian GOST. The limits of this range are 190-245 volts. Out of range, many self-contained power supplies automatically switch to battery mode, even when mains power is available. The battery capacity is designed for a short period of time. If your mains voltage is out of range, then you need to install a voltage stabilizer in front of the power source for the boiler. The required power is small. Approximately 500 - 1000 VA is enough. The second option for solving the voltage problem is to install a UPS for an online type boiler. Such autonomous power supplies have a wider range of operation from the input mains. The range is 150-260 volts and some models have 100-300 volts. By installing such sources, the consumer receives an additional bonus - a built-in filter for frequency noise. Naturally, such autonomous power supplies cost more. The decision is made by the consumer himself according to his capabilities. The cost of such an uninterruptible power supply can even exceed the cost of an offline type UPS kit plus an inexpensive voltage stabilizer. Buying a set of UPS 300 plus a battery 100A / h in our store, you get a voltage stabilizer as a gift, without any additional conditions.
The next main property is the shape of the output signal. There are many different types of uninterruptible power supplies. For example, an uninterruptible power supply for a computer has a rectangular output signal. This form is categorically not suitable for pumps in a heating system. The pumps start to work intermittently, buzzing. The service life is immediately reduced significantly. Reliable operation of the entire heating system, including pumps, is only possible with a pure sinusoidal output signal after a fail-safe unit. Do not listen to salespeople who will start offering an approximate sine (approximated). Although this waveform is almost like a real sine wave, the boiler and pump still work intermittently. Interruptions or false positives of the boiler control board occur. Only a pure sinusoidal signal at the output of the uninterruptible power supply will ensure uninterrupted operation of the boiler and your heating system as a whole.
The last step is to determine the battery life for the boiler. Everything is much simpler here. The time depends on the power consumption of your boiler (the standard version of the boiler with one pump does not exceed 100-150W) and the battery capacity. But there is a pitfall here. No need to immediately rush to buy a battery for an uninterruptible power supply of maximum capacity. First you need to study the characteristics of the uninterruptible power supply. The manufacturer in the characteristics table indicates the maximum allowable power of the battery, its type. If the table indicates the battery capacity of not more than 150A / h, then you can install any battery up to 150A / h. What happens if you still install more power on the UPS for the boiler? The battery will not receive a full charge. If you decide to purchase a simple car battery, then you need a full discharge cycle a couple of times a month. In simple terms, train the battery. Why? Car batteries are designed for daily charge and discharge. If the battery is idle for a long time, then it begins to break down. If there is no time for this, then we recommend special batteries for an uninterruptible power supply. Here the principle is reversed. It is enough for such batteries to carry out a training cycle two to three times a year. The service life of such batteries is very long, about 5-15 years, depending on the modification. Buying a complete set of UPS + batteries for the boiler, you get a 10% discount on any battery for an uninterruptible block.

Modern gas water heating boilers are efficient and economical, but, unlike the old ones, they have a weak point. All new heating boilers are equipped with an automation system, and the system includes a circulation pump, requiring high-quality and uninterrupted power supply. Moreover, the boiler can shut down by internal protection when the mains voltage is low. If the problem of impulse noise and voltage drops can be solved by connecting the boiler and heating system equipment through a stabilizer, then in the event of a power outage, the stabilizer will no longer help - the automation will turn off the boiler, and it will be possible to start it only after the power supply appears. Turning off the heating system can be fatal to the entire system, especially in severe frost. And even if you do not have problems with power supply, no one is immune from the surprises of nature, line breaks and other emergencies. And low voltage in some settlements is almost the norm. Therefore, it is highly recommended to connect the gas heating boiler through an uninterruptible power supply - UPS (UPS).

It should be noted that an alternative to the UPS is an autonomous diesel or gasoline power plant. But it is advisable to use such autonomous power supply systems in conjunction with UPS, with large heated capacities and the possibility of installing such a generator. In the vast majority of cases, the optimal solution will be an uninterruptible power supply, correctly selected in terms of power and technical parameters. It will be much more profitable in terms of price, moreover, it does not require in-line fuel costs (gasoline, diesel fuel). And modern batteries in the UPS are enough for 10-15 years of operation. There is another option for an autonomous solar-powered power system - quite promising, but still a little expensive.

What you need to know when choosing an uninterruptible power supply (UPS) for a heating boiler?

We note right away that it will not work to connect a conventional car battery directly to a gas boiler, because the battery only produces a direct current of 12 V or 24 V. Therefore, to connect an autonomous power supply to the boiler, you need a device that converts the battery’s DC voltage to AC mains 220V . In addition, the conversion must be of sufficient quality (the shape of a sinusoid) to power the electronic components of the system. These devices are called an uninterruptible power supply, abbreviated UPS or UPS.
The functions of such devices are to invert the constant voltage from the battery to 220V AC in the absence of mains voltage, stabilize the output at 220 V, if there is a different input (for example, from 100 V to 300 V), Eliminate overvoltage surges, and also charge the battery when need. Such a device is fully automatic and provides a shockless transition to autonomous power without interrupting the power supply to the boiler and heating system. When power comes on, it automatically turns off the battery and switches to battery charging mode. Batteries are charged according to a certain algorithm, which can significantly increase the battery life.

But not all UPSs provide all of these features. There are two types of UPS:

The first type is an off-line UPS. Automatically switch battery power when there is a power outage and automatically charge the battery when needed. Those. if there is voltage in the network, the device is not involved in any way, the current flows through it in transit and, accordingly, does not stabilize. If the input is 180 V, then the output will be 180 V. The cheapest uninterruptible power supplies for a computer of this type. It is worth noting that switching power supplies for computers, TVs allow you to work normally in a wide range of input voltage (140V-250V, and a wider range). Gas boilers, in general, are much more demanding in this regard and can be switched off at a voltage of less than 190-200V. The instructions do not indicate this limit - look at the forums or ask the experts about the brand of your boiler.

The second type is an on-line UPS that are active all the time. The voltage in the on-line UPS is stabilized by double conversion inverter: First, the 220V AC voltage is converted to 12V or 24V DC, then the DC voltage is converted to 220V AC. Since the DC voltage of 12 V or 24 V is always stable, when this voltage is converted to AC 220 V, there are also no fluctuations, subsidence or voltage surges. As a result, the on-line UPS always gives a stable sine wave and voltage at the output. They also differ in the quality of the generated sinusoid. In addition, a UPS with a built-in voltage regulator allows you to provide a stable voltage to consumers without switching to battery mode. This allows you to significantly save battery life. The uninterruptible power supply with a double conversion voltage stabilizer is by far the most accurate and reliable, and unfortunately the most expensive.

A Few More Notes on Choosing a UPS for Your Heating System

Inexpensive computer UPSs have a square wave output, which is unacceptable when running pumps, fans, and other inductive loads. To operate the boiler, a voltage with a pure sine wave at the input is required (ensuring smooth engine torque).

Starter batteries are designed to operate on short-term powerful loads (starter start), require maintenance and emit sulfuric acid vapors during operation (not allowed for use in enclosed spaces in close proximity to people). The average life of a car battery in a UPS system is less than one year.

How to calculate UPS power for gas boiler and heating system

When choosing UPS for gas or other boiler it should be noted that the shape of the output voltage of the uninterruptible power supply must be sinusoidal, since the boiler contains consumer devices that are critical to the shape of the input current (fan, circulation pump, gas valve, electronic unit).

Right calculated and selected uninterruptible power supply system for the boiler will avoid problems associated with turning off the boiler or its failure due to voltage drops, as well as ensuring its autonomous operation during the required estimated time.

In the classic version, the electrical power of the heating equipment (do not confuse it with heat) consists of the power consumption of the boiler itself and the circulation pump. You can take this data from the documentation or on the nameplates of the equipment.

In gas boilers up to 25 kW in terms of heat, as a rule, there is one pump. In more powerful, industrial boilers, there may be two or more pumps. In most cases, a boiler with one pump consumes 90-150W of electricity when the pump is on, and such a boiler needs a stabilizer or a UPS with a power of up to 300W. Accordingly, if two pumps are used in your heating system, then you need to take a UPS of at least 400-500W. In general, the power of the UPS should correspond to the total power of all devices powered by it. And do not forget also about the power reserve, at least 20-30%.

Obviously, the larger the battery capacity, the longer the battery life of the UPS. Approximate UPS uptime can be determined from the table below.

Another important indicator of the UPS is the power of the charger. As you know, the larger the battery capacity, the more current is needed to fully charge the battery. The approximate ratio is 1 to 10. Ie. to charge a battery with a capacity of 60 A / h, a charge current of 6A is required. You can also charge with high currents, but this leads to rapid battery wear. If the charge current is less than it should be, then the battery will not be recharged, as a result of which it will "coke" (the technical term is sulfatization), which will also lead to a decrease in service life.

Uninterruptible Power Supply Run Time Calculation

Simplified formula

The calculation of battery life can be carried out using a simplified formula. To do this: The battery capacity in Amp-hours, multiply by the battery voltage, in volts, divide by the constant load in watts and get = Number of hours of continuous battery life.
For example, a boiler that consumes 180 V with a 50 Ah battery will continuously operate for 3.3 hours (50*12/180).

Refined calculation

If you decide to delve into the technical characteristics of the UPS and independently calculate the time of continuous autonomous operation of your boiler and heating system - please! To make a calculation, we will use the only correct method, but for this you need to know not only the power of the boiler, but also several important parameters of the UPS for the boiler:

T- UPS battery life when the network is turned off, h;
Uab- voltage of one storage battery, V;
sak- battery capacity, A * h;
TO- the number of batteries in the battery;
h- Converter efficiency (h=0.75-0.8);
Cr- coefficient of depth of discharge 0.8 -0.9 (80% -90%);
Kg- coefficient of available capacity, depends on the discharge mode and temperature:
- with a one-hour discharge mode, tamb=20°C 0.7 (70%)
- with a two-hour discharge mode, tamb=20°C 0.85 (85%)
- with a ten-hour discharge mode, tcr=20°C 1.0(100%);

T \u003d Uab * Sak * K * h * Kr * Kg / Rload

Where Rnagr - load power.

To take a closer look calculation of an uninterruptible power supply for a boiler let's substitute the approximate values:

Uab = 12 V;
Sak \u003d 84 A * h;
K = 1.0;
h = 0.8;
Kp = 0.9;
Kg = 1.0.

Pload = 150 VA.

T = 12 x 84 x 1.0 x 0.8 x 0.9 x 1.0 / 150 ≈ 4.84 hours

Thus, if your heating boiler has a capacity of 150 VA and is powered by an uninterruptible power supply with a battery with a capacity of 84A * h at 12V, then the battery life will be 4.84 hours.

What is the best selling boiler UPS?

Based on the most requested initial data, the most common UPS configuration for a boiler is a double conversion UPS (it has a constant, stable output voltage), an operating power of 300W and a short-term peak load of up to 1000W.

What is the best battery for a boiler?

The best price / quality ratio has a 12V 100A battery. The difference in cost between batteries of 50 amperes and 100 amperes is only 30-40%, and between batteries of 100 amperes and 120 amperes is already about 50%. Thus, as one or more backup batteries, it makes sense to look towards the 12V 100A battery.

These are reference data, and it will not be difficult for you to determine the required UPS parameters for a particular boiler and heating system using any formula, and according to the known parameters, you will already choose the UPS model - there are quite a lot of them on the market now, as they say for every pocket and taste.

There was already an article on the site about how to ensure uninterrupted power supply to heating boilers. You can find it by searching the site or through the heading "Reserve equipment". However, as many people know, a UPS for gas boilers is slightly different from any other uninterruptible power supply for other types of boiler equipment.

What is different in the first place? Let's look together and understand this issue.

UPS features for gas boilers and differences

So, how do UPSs for gas boilers differ from all other backup equipment. Let's start with some general numbers.

The most common uninterruptible power supplies are now the so-called "computer". They are suitable for powering pulse blocks of modern computer technology and produce an approximation of a sinusoid at the output - a kind of "semi-step" signal.

Such a signal is quite suitable for impulses, but not at all suitable for powering any electric motors. In a modern heating system, everything is built on circulation pumps. In radiant heating systems, there are from 2-4 such pumps per house. And less and less people are thinking about a system with natural circulation.

And therefore, you can forget about the UPS for the boiler, which does not support a pure sine at the output, as a backup power source.

This is followed by simple off-line UPSs that produce pure sine output and switch to battery power in the event of a power outage. Such uninterruptible power supplies are quite suitable for power or diesel boilers.

An important characteristic for such UPSs is the ability to connect and charge an external high-capacity battery - from 100 to 1000 Ah.

However, the time for switching from a 220 volt network to battery power is usually 4ms, which is enough for various boiler equipment, but can be critical for.

At the moment of switching, the boiler automation remains without power. And no matter how small this figure of 4ms is, for some models of gas boilers this is enough. The boiler automation “flashes”, after which the gas boiler goes into the “error” mode and cannot start on its own.

The “cold start” function of the off-line UPS slightly corrects the situation, which allows you to start the boiler from a backup power source. Those uninterruptibles that do not have such a function can not start a boiler of any type from a battery.

How to choose an uninterruptible power supply for a gas boiler?

It turns out that UPS for, and sometimes entire lines from one manufacturer, can be off-line with a "cold start" function. But, as the UPS reviews show, sometimes this is not enough and some gas boilers do not start even in conjunction with such uninterruptible power supplies.

For example, I will give the Inelt Intelligent 500 and 1000 series, which quite correctly support the operation of the automation of diesel boilers and any solid fuel heat generators, but sometimes they cannot start a modern gas boiler.

What can be done to ensure that the automation of a gas wall or a modern floor-standing condensing boiler functions smoothly? Which uninterruptible device for a gas boiler to choose?

More expensive versions, for example, the same brand Inelt, the Monolith series can already work in on-line mode, when there is no such option as switching the UPS from 220 volts to power from a backup battery. The principle of double conversion used in such uninterruptible power supplies allows the UPS to supply the boiler with a constant voltage in the form of a pure sine and does not depend on the situation in the network.

On-line UPS in this regard is the best uninterruptible power supply for a gas boiler, regardless of the state of the current in the 220 volt supply network.

The automation of any boiler, whether it be floor-standing, will be able to work correctly and will not even “notice” the transition from mains power mode 220 to battery power mode.

Naturally, only specialized models should be used to power the gas boiler, which can be charged and powered by a large capacity battery. On-line uninterruptible power supplies for computer needs are too small built-in and additional batteries.

For example, a standard built-in APS battery to power a 1kVA UPS is 24Ah and another 24Ah extra battery in an extended battery pack. 49 amp-hours is all the "computer" circuit has to offer. And to power a gas boiler for at least 12-24 hours, a capacity of 2-4 times more will be required. Because in addition to powering the automation and the boiler burner, you also need power for at least one circulation pump.

It turns out that, if we talk about the support of absolutely any model from any manufacturer, it must necessarily have the following characteristics:

It must be an on-line UPS with double conversion of the incoming voltage.
The output should be a pure sine wave.
The capacity of the supported battery must be at least 100 Ah.

All other features, including programmable features and SMS notification to the owner, are not as important and are a nice addition to models in the higher price range.

What inexpensive UPS models can be recommended for guaranteed power supply to a gas boiler? These are uninterruptible power supplies with an initial price of 8000 - 9000 rubles. The simplest representatives of the lines of such UPSs:

Ippon Innova RT 1000 and 1500
DeltaES GA2000R
Helior Sigma 1KSL
Stark County 1000 Online
Source IDP-1/1-1-220-A
P-Com Pro 1H
Inelt Monolith K 1000 LT

These models will guarantee the operation of any gas boiler in conditions of poor quality electricity in networks or in case of accidents on power lines. Naturally, the battery life of a gas boiler will depend on the total capacity of the batteries that you connect to any of these UPSs.

Question on the topic - a stabilizer for a gas boiler

All of the above solutions are good when the owner does not have the opportunity to be near the house all the time and control the operation of the boiler.

If you don’t leave anywhere for a long time and can manually start your gas boiler, then a simpler and more budget solution will come in handy.

They can be the use of an inverter with a pure sine output as a power source when turned off and a stabilizer for a gas boiler when powered from a 220 volt network.

How would such a scheme work?

The stabilizer for a gas boiler provides protection for the automation of boiler equipment when powered from a power line, smoothes and dampens power surges and, if the voltage level is insufficient, produces the required 220 volts.

An electromechanical stabilizer is not suitable for such work, its response time to changes in voltage parameters is too long. You will need an electronic stabilizer that will not only allow you to get the required value at a low or high voltage level, but also protect the electronics from interference and power surges.

The simplest solutions in this matter are offered by the Resant and RUSELF brands, which produce electronic type stabilizers, ranging from single-phase 0.5 kVA to three-phase 20 kVA.

Naturally, you will need a single-phase stabilizer, the power of which you will select based on the required loads for your equipment:

Circulation pump power supply (50-95 watts)
Power supply for automation and boiler burner (100-250 watts)
Power supply for room temperature sensors and weather-dependent automation.

In the event of a power outage, even a short one, the boiler operating according to this scheme will turn off.
You connect a pure sine inverter powered by a battery to it and start the boiler again.

How much would such a solution cost? Let's count.

The simplest stabilizer for a gas boiler from a reputable manufacturer costs 800-900 rubles. This is for models from 0.5 kVA. The simplest inverter with a pure sine of 0.5 kVA costs from 2500-3000 rubles.

That is, apart from the cost of the battery, such a scheme will cost you 3000-4000 rubles, which is about 2 times cheaper than the cheapest UPS for gas boilers.

What to choose - inexpensive autonomy under supervision or full automation is more expensive - you decide. All the arguments in favor of one way or another I have given above.

And, finally, my advice for those who are going to choose an uninterruptible power supply for a gas boiler and read reviews on the Internet. Remember that many reviews on models on the Market and other popular services are "inflated", posted by people for a fee and published by sales managers of equipment manufacturers.

In order not to get into a situation where, it would seem, the model recommended by many users turned out to be not as good as it was described in the reviews, read forums like ForumHouse.Ru. On such resources, users very quickly bring sellers advertising their goods “to clean water”.

On this page, we will consider all the subtleties and designate the sequence for choosing an uninterruptible power supply for a gas boiler.

If you are choosing for a solid fuel boiler, then please go to a special page dedicated specifically to the uninterruptible power supply of solid fuel heating boilers, (UPS for different types of boilers are different).

For those who do not want to delve into all the subtleties of choice, we have made an automated system for selecting an uninterruptible power supply for the boiler and calculating the required battery capacity. To use it, you need to specify the type of boiler (gas or solid fuel), enter the power consumption of the boiler in Watts and the desired autonomy time in hours and on the screen you will see the possible options for kits uninterrupted power supply. This is a test version of the program and it covers 75% of cases. However, if you have non-standard requirements for uninterrupted power supply of the boiler, namely, the autonomy time is very long or the power of the boiler with external circulation pumps is more than 2-3 kW, then of course an individual calculation and selection of the optimal configuration is necessary.

Anyway for the heating season 2018-2019 we have prepared THREE necessary bonuses for those who decide to buy an On-Line uninterruptible power supply for the boiler in our NON-INTERNET store. Yes, we do delivery, both in Moscow and throughout Russia, but we do not consider ourselves an online store, due to the fact that you can and should come to us (on Vavilov 9A), where you will get to know each other and learn how to correctly assemble, connect and use what you buy equipment. And if there is no such opportunity to come, then we have all uninterruptible power supplies and batteries for them in our warehouse, and before selling we check each unit. We don't need refunds.

When buying from us, three bonuses as a gift:

1 bonus. Since the spring of 2014, due to the increasing cases of damage to UPSs for gas boilers from indirect lightning strikes into power lines, we supply each sold set (UPS + battery) with a separate varistor protection. This saves the UPS input circuits from residual overvoltage. It is much easier to replace this unit with a new one than to carry the UPS itself for repair! Of course, this is not complete protection, we will talk about full protection below, but we want to identify the problem! (Supplied with On-Line UPS only)

2 bonus. We complete each UPS with additional instructions on how to connect correctly. This is not written in the official instructions, but without this, installation errors are possible! In this manual, we indicate in detail the sequence of actions for determining the phasing, we consider typical problems, such as the failure of the boiler to work with the generator through the UPS, malfunctions in the "gas control" system, how to maximize battery capacity in the summer season. Thanks to this material, many of our customers have found answers to emerging situations and saved time and money without calling additional specialists to connect the UPS.

3 bonus. We make sure that during the installation of the UPS, you do not need to purchase additional accessories (wires, adapters, jumpers). Therefore, before we complete between the battery jumpers of the length you need, and if necessary, for some UPS models, with output adapters for euro sockets.

Examples of already assembled On-Line kits for different battery life:

To evaluate the capabilities of the kit by the autonomy time The photos of the kits show several UPS autonomy times depending on the load. Only two powers are indicated, this does not mean that this kit can only "pull" 250 W, for a rough estimate if you need 500 W, the indicated time for 250 W divided by 2 is enough.
Look carefully at the tables, the same autonomy time can be achieved with three sets, but which include 1,2 or 3 batteries.
The question is what to choose? The optimal solution is a UPS with two batteries, in case of low boiler power and limited dimensions for installing the system, of course, a kit with one battery is a reasonable solution, and for the maximum value of 700-800 W it is better to use a UPS powered by three batteries. This position is explained by the thermal modes of operation of the UPS inverter. The lower the voltage of the battery pack, the more difficult it is to raise it to 220-230 volts, and as a result, the thermal conditions are more severe. And this affects reliability! Below are three lines of UPS, arranged according to the principle of the number of batteries, how to select the number of batteries in the UPS on the page.

UPS kits with one external battery

UPS with one external battery: the main advantage is the size, the ability to urgently connect a car battery to the discharge. The disadvantage is the price, efficiency, reliability.

UPS kits up to 800W with two external batteries

The operation of a modern gas boiler, despite its main non-volatile heat source (natural gas), is supported by various electronics. Auto-ignition, flame detection, temperature maintenance, gas flow control and more - these are her tasks. Therefore, it is imperative to install an uninterruptible switch for a gas boiler in the boiler room in order to ensure stable and uninterrupted power supply boiler, otherwise you risk damaging the heating system and freezing when the power goes out.

All UPSs, in particular UPSs for a heating boiler, according to the electrical diagram can be divided into the following types:

on-line(online, double conversion UPS). This uninterruptible power supply device consists of a rectifier, inverter and batteries. First, the alternating current from the 220 V network is converted into direct current, which charges the batteries and feeds the inverter. With the help of a constant voltage and an inverter, electronics can very accurately maintain a constant output voltage with large fluctuations in the input. The most accurate and reliable, but also the most expensive scheme.
off-line(offline, or backup). They have the simplest circuit, the purpose of which is to transfer the consumer to batteries when the input voltage is too high or low. Voltage stabilization is completely absent, but such models boast the lowest price.
line-interactive(linear-interactive). They look like offline UPSs, only they have a simple voltage regulator in their composition, which allows you to keep it normal with acceptable accuracy.

Battery connection

Also, the UPS of a gas boiler can be divided according to the method of installing batteries: external and internal. The latter are similar to computer uninterruptible power supplies, they are small in size (often wall-mounted UPS) and at the same time have little autonomy. Basically, boiler UPSs are available with external battery connection, they have a long operating time and, as a rule, the ability to increase capacity if necessary.

Batteries for such UPSs are placed on shelves near the main unit.

How to choose?

Criterias of choice:

Only pure sine wave output. The boiler electronics, as well as the asynchronous motors of the circulation pumps, are only designed for sinusoidal alternating voltage. Many computer UPSs and some cheap boiler uninterruptibles can produce a square wave or "modified sine wave", resulting in shortened electronics life, humming, and failure of pumps.
Power. Determine which heating devices will be connected to the uninterruptible boiler for the boiler (pumps, lighting, etc.) and what their power is (indicated on the instrument case or in the instructions). We add up all the obtained power values, add 5-10% and get the required UPS power for the boiler.
Battery capacity. It depends on it how long the gas boiler will work from the UPS in the event of a power failure. The battery life can be calculated using the formula: T [h] = C [A*h] * V [V] * 0.85 / P [W]. Here: C is the total capacity in ampere-hours (A * h, Ah), added up when the batteries are connected in parallel; V - voltage in volts (V), added up when batteries are connected in series; 0.85 - typical efficiency for UPS; P is the total power of the connected equipment in watts, calculated according to paragraph 2.
The type of batteries used. Do not use car acid batteries: they are not designed for buffer operation in an uninterruptible power supply for the boiler, they can be a fire hazard. Choose AGM or gel (GEL) batteries.