Types of uninterruptible power supply. Uninterruptible Power Supply (UPS)

Poor quality power supply is one of the main problems of failure of household, office or industrial equipment. Despite the fact that interference occurring in the electrical network is periodic, it has a detrimental effect on the components of modern electronic devices plugged into an outlet. To protect critical equipment or preserve data in the event of a power failure, power supplies are most commonly used. uninterruptible power supply.

Basic operation schemes and areas of application of uninterruptible power supplies

The purpose of the UPS is to ensure correct operation of the load during sudden “dips” or “spikes” of voltage, as well as to ensure short-term battery life connected equipment when complete shutdown electricity. Modern uninterruptible power supplies are divided into three classes:

Backup or Offline
Linear interactive
With double energy conversion

Their design and functionality are somewhat different, but everyone can figure out how to use an uninterruptible power supply.

Why do you need a backup UPS? Its main area of application is the protection of household computer and multimedia equipment. The scheme of its operation is extremely simple: in normal mode, the load is powered from the network, and when the voltage in it disappears, the device switches to battery mode. The switching time between operating types is non-zero. It is relatively inexpensive and will protect equipment from minor voltage surges and short-term power failures.

The advantages of a line-interactive UPS are smoother signal stabilization and the ability to operate in a wide range of input voltages. Such devices do not allow you to adjust the signal frequency when powered from the mains; when powered by battery cells, they can produce a “pure” or approximate sinusoid. How can I use the Line-Interactive uninterruptible power supply? It is perfect for protecting monitors, system units, LAN nodes, workstations, computer peripherals and other devices with pulse blocks nutrition, which makes it excellent.

The most advanced in terms of equipment protection is a double-conversion UPS. But what is valuable in an uninterruptible power supply developed according to the Online scheme? It is characterized by instant switching between operating modes and independence of the output signal parameters from the parameters at the UPS input. Therefore, this particular type of UPS is designed for switching equipment that is especially demanding in terms of power supply quality. Among the UPS Online topologies, based on the scope of their application, the following types can be distinguished:

Alternative protective equipment options

Many people ask the question: is an uninterruptible power supply necessary if the voltage in the network does not disappear, but simply “jumps”? Do you need a UPS for your computer in this case? The answer to these questions may be a look towards voltage stabilizers. These devices allow you to correct the signal over a very wide range, applying a voltage to the load input at a level specified by the user. This is the main advantage of these devices. The main disadvantage is that the stabilizer stops working simultaneously with the disappearance of voltage in the electrical network. The main problem of stabilization devices is the inability to ensure autonomous operation of the load. Therefore, it is important to clearly understand what exactly the equipment needs to be protected from: from signal level fluctuations or from frequent and short-term power outages. In the first case, the way out of the situation will be a voltage stabilizer, in the second - an uninterruptible power supply, the purpose of which is somewhat broader.

But what to do if the signal level in the power grid is relatively stable, but there are long-term power outages? A way out of this situation may be to purchase a diesel generator. They are available in different power ranges and can be used to service both domestic and industrial facilities. There are diesel and gasoline models. The starter of the device can be either manual or electric. The advantage of using such an installation is that it can provide long battery life for the equipment with breaks only for maintenance or refueling. This equipment is compact, easy to maintain and easy to operate.

The operation of diesel generator sets is not without a number of disadvantages, these include:

Inability to independently switch to power supply to the load when the voltage in the power supply network disappears;
Noise during operation;
Presence of exhaust gases;
A large number of consumables (candles, fuel, etc.)

Comprehensive solutions for protecting electronic equipment

To ensure maximum protection for telecommunications, server or industrial equipment, using one type of device may not be enough. Therefore, the most optimal solution may be to combine them. For example, a UPS for emergency lighting will not provide the required level of autonomy. This problem is solved by connecting an uninterruptible power supply unit and a diesel generator set in series. Why do you need an uninterruptible power supply in such a scheme? To filter the voltage and ensure autonomy of the system until the generator starts and enters operating mode.

Why and how can you use an uninterruptible power supply in combination with a voltage stabilizer? For the correct operation of equipment in areas of the power grid where there are frequent voltage drops that are not accompanied by a complete shutdown. Due to this, a significant reduction in the cost of the design can be achieved: an inexpensive stabilization device will provide effective signal correction, and a mid-level UPS will allow you to achieve an acceptable level of autonomy.

The main purpose of an uninterruptible power supply (UPS) is to temporarily provide power to equipment during power outages. It is common practice to connect computers via a UPS everywhere. True, for many users this is a kind of “rule of good manners”, and the practical meaning of this ritual eludes them. “Well, a UPS protects your computer from power surges...” Let's try to figure it out: what, from what and how does the uninterruptible power supply protect?

According to the internal structure and logic of operation, all UPSs are divided into three classes: passive, line-interactive and double conversion UPSs. Accordingly, they cope with incidents in the power grid to varying degrees and belong to different price categories.

Passive(stand-by, VFD, back-UPS, backup) sources are the simplest and cheapest. In them, the battery power circuit is usually turned off and starts only when there is a power failure. The switching time from mains operation to battery operation is tenths of a second, and the output signal when operating on battery power is noticeably different from the “correct” sine wave. As a rule, a simple noise filter and a high-speed fuse are installed at the input of such UPSs. The first partially smooths out impulse noise, and the second should operate when the voltage in the power network increases significantly. Passive UPSs are designed to power home and office PCs. A small “dip” in the output voltage at the moment of switching to the battery is not dangerous for computer power supplies.

Linear interactive(line-interactive, VI, Smart-UPS) UPSs differ in that the battery power circuit is constantly switched on. When the voltage at the input of the uninterruptible power supply disappears, its output sockets almost instantly switch to the internal converter - for the powered devices this transition is almost imperceptible. In addition, many line-interactive UPSs are capable of automatically maintaining an output voltage of 220 V. This is done in two ways.

As long as the mains voltage is between 175 and 275 V, the AVR (Automatic Voltage Regulation) mechanism is activated. When the input voltage deviates from 10 to 25% below the nominal value, the UPS increases the output voltage by 15%. When the input voltage deviates from 10 to 25% above the nominal value, the UPS reduces the voltage by 15%. If the mains voltage exceeds the limit values, the line-interactive UPS switches to battery power. In this mode, it continues to operate until either the mains voltage returns to normal or the battery is discharged. However, such UPSs should not be considered as voltage stabilizers. Their “stabilization” mode is forced and short-term!

IN Double conversion UPS(double conversion, VFI, Online-UPS) the output voltage is constantly supplied from the converter, the converter is constantly running on battery power, and the battery is continuously charged from the network. In fact, the input and output of the UPS are galvanically isolated from each other, and a stabilized voltage is supplied to the output. This is the most reliable, but at the same time uneconomical scheme. The UPS itself is expensive, large and heavy, the converter gets very hot and requires fan cooling, and energy losses during conversion amount to tens of percent.

Double conversion UPSs are used only to power servers and computers in critical applications. Such models rarely go on general sale - they are usually supplied to order. Most likely, to power your work computers you will purchase passive, maximum, line-interactive UPSs.

The power of uninterruptible power supplies is usually indicated in volt-amperes (VA, VA). To convert these values into more familiar watts (W), you need to multiply the power in volt-amps by a factor of 0.6. For example, a UPS with a power rating of 600 VA will provide power to equipment with a maximum consumption of 360 W. If you give a large load, the current protection will work and the uninterruptible power supply will turn off. In practice, it is desirable to provide about 30% power reserve. Thus, the most common 600 or 650 VA UPSs are suitable for powering a computer with a real consumption of 200-250 W and a monitor, which takes about another 30-60 W.

If the arrangement of computers in the room allows, it is more profitable to use one powerful UPS instead of several small ones. For two office computer you will need an uninterruptible power supply with a power of about 1000 VA. To power three computers standing next to each other, one source with a power of about 1400 VA is sufficient.

So what does a UPS protect against?

Filters in the power supply of the computer and monitor also do a good job of limiting impulse noise from the network. However, two filters are better than one! Surge protection is also important. If, for example, the neutral wire in the panel burns out, the voltage in the socket may be almost 380 V. In power supplies for computers and monitors, in this case, varistors and fuses usually burn out. Repairs are cheap, but take time. In theory, the UPS should respond to a voltage surge before the fuses in the equipment connected to it burn out.

However, data protection comes first. If the computer's power is turned off, all unsaved information is lost. The UPS allows you to either save open documents and shut down gracefully, or put the computer into sleep mode. Manually saving documents is the easiest way. When switching to battery power, the UPS begins to beep loudly. Once you hear such a warning, check if everything is saved. Next, look at the situation: either simply turn off the computer, or put it into sleep mode.

To activate the automation, you need to connect the control port (USB or RS-232, depending on the model) of the uninterruptible power supply to the computer with a signal cable and install the necessary software on the computer. Unfortunately, many users are not even aware of this possibility! The operation of the UPS is controlled by a built-in microcontroller. Its microprogram (firmware) constantly monitors voltages and currents in external circuits when turned on and periodically tests the electronics and battery during operation. It also provides the control port with information about current mode operation, condition of UPS components. This data is transmitted via cable to a computer, where it is processed by a monitoring program.

To work with the UPS, it is advisable to use the program offered by its manufacturer. For example, for APC (www.apc.com) this is the Power-Chute program, for Ippon (www.ippon.ru) - WinPower2009 and Ippon Monitor, etc. The program can be installed from the disk included in the kit, but it is better to download the most its latest version from the manufacturer’s website.

You need to set parameters in the application settings automatic shutdown. As a rule, there are two options to choose from: either turn off the computer after a certain time after switching to backup power, or do it some time before the batteries are expected to be completely discharged.

How long can an uninterruptible power supply operate on battery power?

This depends on the battery capacity and power consumption. Most mass-produced models have one battery with a voltage of 12 V and a capacity of 7 Ah. Theoretically, a UPS with such a battery has an energy reserve of about 80 watt-hours. Simply put, it should power an 80 W load for about 1 hour, 160 W for half an hour, 300 W for about 15 minutes, etc. In reality, taking into account conversion losses, this time is approximately half that time.

In sources with a power of more than 800 VA, two of the same batteries or one, but with a larger capacity, are usually installed. Tables or calculators to determine battery life at different loads for various models are provided on the manufacturers' websites. However, “offhand” we can assume that any model will be able to power a load of its rated power for about 5-15 minutes. If you need to provide power to your computer from batteries for a sufficiently long time, it is better to take a high-power UPS with capacious batteries. It will operate at only a third or a quarter of the rated power. But he will be able to supply such a load, low for himself, with energy for half an hour or longer.

Network equipment (switches, routers, NAS) also benefit from uninterruptible power supply. Otherwise, when the power goes out, the network will immediately “fall”, and documents opened from network folders, it will not be possible to save. You can power the switch from the UPS of the workstation closest to it, although it is more correct to install a separate “uninterruptible power supply” of low power for this.

Battery life is limited. As it operates, its capacity steadily decreases and after 3-5 years of operation it drops to almost zero. Even before the indicator on the UPS signals the need to replace the battery, it becomes noticeable that the battery is no longer “holding a charge.” Each time the battery life gets shorter. In principle, a couple of minutes are enough to save documents and correctly turn off the computer. When the UPS starts to shut down even earlier, it’s definitely time to change the battery.

Replacing the battery is easy. In popular APC brand UPSs and some others, the battery is located under a removable hatch or cover. To get to the battery in UPS brands Ippon, SVEN and similar in design, you need to unscrew the four screws on the bottom and separate the halves of the case. In the instructions and on the official website, you are unlikely to find a description of self-disassembly and replacement: like printer manufacturers, UPS manufacturers receive a significant share of their income from the sale of “original” batteries with their installation in authorized service centers.

However, almost all computer stores sell sealed lead-acid batteries in the most popular sizes. The brand and manufacturer do not matter: these are completely standard products. First open your UPS and find out what kind of battery is installed in it. For most “office class” UPSs (500-700 VA), batteries marked 12V 7Ah with dimensions of 151x94x65 mm are suitable. Installing new battery, try to fit the terminals tightly onto the contact tabs of the battery. If the terminals are loose, they can be carefully tightened with pliers.

After installing the battery, it is advisable to calibrate the UPS so that its firmware evaluates and remembers the parameters of the new battery. Fully charge the battery within 24 hours. After this, remove the plug from the socket so that the UPS switches to autonomous power supply. Allow the battery to completely discharge until the uninterruptible power supply switches itself off. It is better to use not a computer as a load (although in extreme cases this is acceptable), but several light bulbs with a total power of about 300 W. Then reconnect to the network and turn on the UPS - let the battery charge and the device continue to operate as normal. In addition to calibrating the device as a whole, this procedure also “trains” the battery. After a complete discharge-charge cycle, the battery begins to use its capacity to its maximum.

Why do many UPSs have telephone (RJ-11) and network (RJ-45) sockets?

By definition, uninterruptible systems do not need a telephone or a local network. Just as a “bonus”, pass-through impulse noise filters for the telephone line and network are installed in the same housing with the device. Connect one socket to telephone socket on the wall, and turn on the telephone in the other. If high-voltage interference occurs in the telephone line, for example, during a thunderstorm, the filter will smooth out the voltage surge and protect the phone.

It is difficult to classify the electrical networks of Russian cities as modern. The equipment is outdated, repairs are not carried out, voltage drops have become the norm. All defects and malfunctions have an extremely negative impact on the work of consumers. Poor-quality power supplies have a particularly strong impact on computer and microprocessor devices, causing not only isolated failures, but also a complete loss of performance. Unfortunately, electrical equipment is often not protected from such surges, and an uninterruptible power supply will help solve the problem. According to the configuration of the phases of the outputs and inputs, UPSs are divided into two types: single-phase input - output and three-phase input - output.

Why do you need a UPS?

First of all, these devices prevent damage to equipment and prevent operational failures electronic systems. They make it possible to shut down work correctly in the event of an unexpected power outage.

With the help of a UPS, interruptions and electrical interference that periodically occur in home and work networks are successfully overcome. Among them, the most common are the following:

Voltage dips. In this state, the voltage suddenly drops by a significant amount. To restore it, various time intervals are required, in some cases tens of seconds. The cause of failures is most often associated with the limited capacity of the substation, especially in winter, as well as with the startup and further operation of powerful equipment. Physically, low voltage manifests itself in the form of flickering lights.
Voltage impulse. IN in this case the voltage changes sharply, with an amplitude of up to 2000 volts, and then returns to normal levels in a very short time. This requires no more than 10 milliseconds. The main reason is considered to be the operation of industrial equipment, air conditioners, elevators, lightning strikes, etc.
No voltage for a short time. This gap is no more than 20 milliseconds and is practically unnoticeable. However, electronic equipment is negatively affected
No tension for a long time. This period can range from 20 milliseconds to several hours. Causes include overloads, adverse weather conditions and physical damage at substations that cause power lines to go down.
Changes in frequency over a short period of time when high-power equipment is connected to the network. RF noise also has a negative impact when connecting radio transmitters, loads, generators and industrial equipment.

Electronics companies have conducted studies that show that every Personal Computer within a month, at least 120 times are exposed to various negative influences, one way or another related to voltage problems in electrical networks.

Basic functions of the UPS

In accordance with known problems that regularly arise in electrical networks, uninterruptible power supplies perform a number of important functions aimed at eliminating them and preventing negative consequences.

The purpose of an uninterruptible power supply is to do the following:

They filter the supply voltage and reduce the noise level.
Absorbs short-term voltage surges, including minor ones.
Protects against short circuits and overloads.
In the absence of voltage in the network, they provide the load with backup power supply for a set period of time.

The most advanced UPS models can produce additional useful actions, thanks to specialized software, designed to control these devices:

The load is turned on and off according to commands from the internal timer exactly at the specified time.
In case of prolonged absence of voltage, it is carried out automatic maintenance equipment, as well as its restart after restoration of normal power.
Emergency situations are monitored and various warning signals are issued.
The device display shows the AC voltage and frequency in a given network, as well as the output supply voltage and power consumed by the load.
Monitoring and recording data regarding the state of the UPS. This includes battery temperature, charge level, and other performance characteristics.

General diagram of operation of uninterruptible power supply devices

Most UPSs are equipped with the following components according to their operating patterns:

An inverter that generates a sine wave.
Rechargeable batteries that store electricity.
Electronic circuit to manage all processes.
Software.
Battery charging device.

If necessary, the device can be organized remote access using a local network. The reliability and performance of the circuit is increased by its redundancy.

Uninterruptible power supplies can be in the following operating modes:

Charging period. The sine wave circuit at the input and output is interrupted by the internal switch of the device. The battery connected to the rectifier is charged until its optimal capacity is restored.
Ready period. Once the battery is charged, the device's internal switch automatically closes. The battery goes into buffer mode and maintains a state of readiness for further operation.
Discharge period. The battery is automatically transferred to power the load, which leads to its gradual discharge.

Specifications

All uninterruptible power supply devices have a certain set technical characteristics. They differ in individual parameters, depending on the design and modification of a particular device.

Each of them has its own input voltage ranges when the UPS operates from the mains and does not use the built-in batteries. It should be remembered that longer ranges reduce battery life, thereby increasing their service life. In addition, they continue to supply power to the load from the mains, whereas at a lower range the UPS switches to the battery, quickly discharging it and de-energizing the load.

For all UPS, the output voltage changes when the input voltage changes. That is, it must be maintained at such a level that the connected equipment can operate normally. Low output voltage often leads to malfunctions and data loss. Exceeding gives the same results, and is complemented by failure of the load used.

Of great importance is the quality of switching and transient processes to and from the battery, which should not attract attention and be carried out correctly in a short period of time. The UPS frequency is correctly synchronized with the external mains frequency. In the event of an overload, a special signal is given using light and sound indication. The device itself is switched off when operating from the battery, and the user must promptly reduce the load.

Many devices can be turned on in the so-called cold start mode, when there is no voltage in the main power supply. This function useful during a long-term absence of voltage, when it is necessary to urgently perform some action on electronic equipment.

Single-phase input - output (1ph / 1ph or 1:1)

Single-phase uninterruptible power supplies were designed for single-phase power supply. They reliably protect electrical equipment that requires increased requirements for the quality of power supply, from any problems in the network (for example, absence or distortion of voltage, suppression of high-frequency interference).

Such equipment maintains the quality of the output voltage if there are problems with the input voltage through the use of battery energy (nominal deviations, dropouts, shape distortions). Single-phase UPSs are used in many areas of information technology and communications.

Three-phase input - output (3ph / 3ph or 3:3)

Three-phase types of uninterruptible power supplies are usually used for continuous 24/7 operation. The device is suitable for powering three-phase equipment, which is designed for 3x380 V and for single-phase energy consumers operating at 220 V. Three-phase UPS maintain the required quality of the output voltage. They are used in banks, computer centers, medical centers, transport, etc.

Types of uninterruptible power supplies

Based on its type, the uninterruptible power supply is divided into three categories.

Interactive UPS (line-interactive)

This is the most ideal option for the home, namely where the voltage is unstable and often disappears. Compared to other types, there are two important aspects. First, they operate much faster, in 2-5 milliseconds. Second, before switching, they try to equalize the voltage, which works quite effectively with small surges. As a result, battery life improves and a lot of money can be saved. This is an ideal option for home use.

These devices are distinguished by a more complex circuit, which includes a voltage stabilizer with an autotransformer that has a step control function. These devices only adjust the output voltage, but cannot control the frequency of the signals. Complete stabilization is impossible due to the small number of adjustment steps.

More expensive types of models are equipped with inverters with semiconductor switches. When switching to battery power, they have more high performance compared to other devices.

Offline uninterruptible power supply UPS (off-line)

The most inexpensive type. The principle of operation is that in the event of a power failure or surge, switch the equipment to battery power. This type has significant disadvantages. The first is the response time, it is about 10 milliseconds. Secondly, if the voltage in your home is constantly fluctuating, such a UPS will often switch to battery power, this will significantly reduce its resource and you will have to change it after a few months.

Online UPS (on-line)

The most expensive and efficient uninterruptible power supply. It regulates voltage in real time, switching to the battery only in the most difficult situations. Often used for servers that require high-quality power. The battery is permanently connected to the circuit and does not require any additional switching.

How to choose the right UPS

Before choosing a device, you need to decide which power supply problems will be most pressing.

For residents of new areas located in large cities, the simplest offline devices will be sufficient. In these places, new networks are usually laid that provide stable voltage. Therefore, in addition to the UPS, it is recommended to purchase a surge protector just in case. It cannot be connected to the output of an uninterruptible power supply to avoid distortion of the current characteristics. When choosing uninterruptible power supplies for offices and large local networks You can choose any of the options discussed above, in accordance with operating conditions.

When choosing an uninterruptible power supply (UPS), you should pay attention to the following parameters and technical characteristics:

Output power value
The time required to switch to battery power and back.
Opening hours in offline mode, depending on the capacity of the batteries and the power of the equipment connected to the UPS.
The width of the input voltage range at which power can be stabilized without switching to batteries.
The battery life is on average from 5 to 10 years.

Content:

The stable operation of computers and other office equipment depends entirely on the availability of power in the network to which they are connected. In the event of a power outage, the equipment will simply stop functioning. IN modern conditions this problem is easily solved by connecting an uninterruptible power supply. Therefore, many people are concerned about the question of when there is a need for a UPS for a computer: what should you pay attention to when purchasing of this equipment. What parameters and criteria should be taken into account?

It is recommended to initially decide for what purpose this device is needed. If the problem is only in stabilizing the mains voltage, you can get by with simpler and cheaper ones. However, in case of regular power outages, you will definitely need a UPS, which must be selected correctly for a particular computer.

UPS use in everyday life

The main network problems include a complete lack of voltage, the presence of high-voltage impulse noise, short-term and long-term power surges, high-frequency interference and other factors that require the use of a UPS. These devices ensure uninterrupted operation of computer equipment from several minutes to one hour.

The uninterruptible power supply circuit is selected in accordance with the operating conditions, the time of switching the load from the network to the battery and back, as well as the duration of operation of the battery.

UPS for home computer

Before purchasing any device, you should find out how the UPS works. Its unit contains a sensor that continuously checks the characteristics of the current in the network and the voltage level. If the parameters begin to rise or fall too quickly, it disconnects the computer from the network and immediately switches it to use a backup power source.

When switching to spare UPS source supplies light and sound signals. In addition, almost all UPSs have a program that allows you to automatically turn off the computer when the battery charge is depleted. When electric current appears in the network again, the sensor signals this and it switches the computer to power from the network and begins to charge the built-in battery.

The batteries used in the devices are designed for low voltage. To obtain a working value, an inverter converts it to a sinusoidal one. At the same time, the battery voltage increases and equalizes the nominal mains voltage. This way the battery is always ready for use and switches instantly when needed.

During operation, it should be taken into account that operation of the UPS at rated load is only possible for a short time. During this period, you can have time to save the data and turn off the computer correctly. Overloads are not allowed during operation; in these cases, the protection immediately turns off the device output. These problems are easily solved by increasing the battery capacity and inverter power.

Which UPS to choose for your computer

Exist Various types devices for uninterruptible power supply of computer equipment. They differ in their operating principle and are divided into three main types:

Backup UPS. It is used when there is a strong voltage drop in the network or it is completely absent. In this case, the battery switches to the backup UPS. Switching occurs very quickly - within 10 milliseconds or less, which does not in any way interfere with the smooth operation of the computer. When switching during power surges, it is recommended to use a stabilizer. This will increase the battery life. When deciding how to choose an uninterruptible power supply, you should remember that this device has become widespread due to its relatively low cost, high efficiency and low noise level. The device can work offline for 5-15 minutes. When choosing and purchasing, it is recommended to create a power reserve of 20-30%.
Line-interactive UPS. The design of these devices is supplemented with a voltage stabilizer, so they are more functional and expensive. Switching to batteries occurs only in the complete absence of electricity, so the battery life is longer. In offline mode, line-interactive UPSs operate for up to 20 minutes. They are more economical and more high degree protection. Among the disadvantages, noteworthy is the noise created by the stabilizer cooling fan.
Double conversion UPS. They belong to the category of the most complex and expensive devices. In progress alternating current is converted to a constant, and then again to a variable. The output voltage is 220 V and is characterized by an ideal sine wave. The batteries are always on, so no switching time is required at all. When deciding how to choose a UPS for a computer based on power, you need to take into account that these devices ensure uninterrupted operation of expensive equipment, which should not stop even for a short time. The disadvantages are low efficiency, high cost, high level heat and noise generation.

When purchasing a device, you need to pay attention to its main characteristics. The power of the UPS itself is expressed in volt-amperes (VA), and the power of the connected computer is expressed in watts (W). You can convert one value to another using a coefficient of 0.7. For example, if the device power is 1000 VA, then it will be 1000 x 0.7 = 700 W. Taking into account the power reserve, a load of up to 500 W can be connected to this UPS.

In addition, when choosing a UPS for your computer, you should pay attention to the battery life at maximum load, the presence or absence of short-circuit protection for the UPS itself and the connected equipment. It is recommended to obtain information from the seller about the possibility of replacing the battery, check the availability of the display and other specific elements.

How to choose a UPS for a computer based on power

Quite often the question arises, what power should a UPS have? The greater the computer's power consumption, the more powerful its power supply and, accordingly, the UPS must have. Most models express power not in the usual watts, but in volt-amperes.

It is quite easy to calculate the power of a UPS for a computer by multiplying the power of the monitor and power supply in watts by 1.6. Let's say that the sum of the power consumption of your monitor and power supply is 200 W. In this case, you will need an uninterruptible power supply with a capacity of 320 VA (1.6x200). For greater reliability, increase this value by another third. The result will be a value of about 400 VA. Then just look for a model with just that kind of power.

Some users have a problem calculating the power of a UPS for a computer. To do this, you need to determine the load power, which should not be higher than 70% of the UPS output power. For example, the power consumption of the processor is 65 W, the video card is 170 W, motherboard- 40 W, DVD drive- 20 W, HDD drive- 40 W, other equipment - 30 W. The number of possible losses is conventionally taken as 20%. Thus, the computer consumption without losses will be up to 365 W, and with losses - 438 W. Therefore, the purchased uninterruptible power supply must have a power in the range of 500-620 W.

Connecting an uninterruptible power supply for a computer

Sometimes owners of computer equipment have a question: how to install a UPS? You need to connect the uninterruptible power supply to a regular electrical outlet, and then insert the power plugs of the devices that you are going to protect from power outages into the sockets located on its body. If the uninterruptible power supply supports automatic shutdown computer and other control functions that are carried out using a PC, it should also be connected to the system unit, usually using a USB cable.

There are several connection options, including using one that compensates for differences from 140 to 260 volts. This method is used most often, so it should be considered in more detail. In addition to the stabilizer, you will need a surge protector. Before connecting, you need to clarify the parameters of all components. The power of the stabilizer and the UPS should be approximately equal, and the power of the UPS should be higher than the power of the computer power supply.

Connection order:

The voltage stabilizer is connected to the network, after which a surge protector is connected to it.
After this, the UPS itself is connected to the surge protector. There is a button on the body of the device that is pressed and held until the power indicator lights up.
Next, the computer is connected to the UPS, that is system unit and monitor. If additional outputs are available, you can connect speakers, a printer and other equipment.

Some uninterruptible power supplies are equipped with software control, which must be configured correctly after connection. In the control panel, in the “Power Supplies” section, after installing the device, a separate UPS window will appear. Everything is configured in it required parameters depending on the power of the computer and operating conditions.

Greetings, my dear readers! In the current Russian realities, the owners desktop computers forced to solve problems of uninterrupted power supply. This problem can be solved using uninterruptible power supplies. Their diversity on the computer market allows you to choose a UPS to suit your specific needs. We will talk about what a UPS is and what uninterruptible power supplies there are in this article.

A UPS, or uninterruptible power supply, is a device that acts as an energy “battery”. In the event of a power outage, the UPS automatically switches the computer's power supply to power from the built-in batteries, which allows you to correctly shut down the work and save all the necessary documents.

Variety of uninterruptible power supplies

Uninterruptible power supply is your guarantee of the safety of documents and computer components as a whole. After all, if the computer is turned off incorrectly, the HDD, And motherboard, and RAM.

We figured out what an uninterruptible power supply is. Let's move on to the next question.

What types of UPS are there?

Uninterruptible power supplies are divided into three types:

Offline UPS;
Line-interactive UPS;
Online UPS (double conversion UPS).

Let's look at each type of uninterruptible power supply separately. This information will help you when choosing a UPS for your own needs.

Offline UPS

Principle of operation of this type power supply is to automatically switch the computer or other connected device to power from the built-in batteries when disconnected from the external power supply.

Often a mechanical relay acts as a switch, so you may hear a clicking sound when the UPS switches from external source power to batteries and vice versa.

This type has become widespread among ordinary users and in offices.

TO pros Such UPSs include simplicity, compactness and low cost. The main minus is the impossibility of stabilizing the input voltage, and therefore your computer will not be protected from sudden voltage changes. This species also exhibits increased wear and tear on batteries.

Line-interactive UPS

This type of uninterruptible power supply is in most cases used to protect network and other telecommunications equipment, as well as groups of computers.

The main feature of these sources is the ability to adjust the output voltage without connecting to batteries, regardless of the voltage (high or low) at the input.

Pros This type of UPS is small in size, low cost, automatic voltage regulation, and economical.

But he also has minuses– this is a relatively long switching to batteries, the impossibility of adjusting the shape of the output voltage when operating from an external power supply, the change in output voltage occurs in steps.

Double conversion UPS

This type of UPS performs voltage conversion twice: the input AC voltage is converted to DC, and then the DC is converted to a reference AC voltage and supplied to the devices.

Applicable this type where a reference voltage is required and the powered devices are demanding on power quality. The connected devices can be very different: regular workstations, file servers, network devices and other power-hungry equipment.

pros Online UPS has significant features: full control of input and output voltage, zero waiting time for switching to batteries, connected equipment does not in any way affect the external power grid.

Minuses There are also: high cost, complex design, self-consumption of electricity in double conversion mode.

The first type of UPS is quite sufficient for home and office use. But if you have the financial opportunity, I would recommend the latter type to you. This is the most reliable type of protection for your computer equipment from low-quality voltage.

Main characteristics of the UPS

A UPS has several main characteristics that you should pay attention to when purchasing. Let's look at them below.

Power. This characteristic directly determines what equipment can be connected to this UPS. Always choose a source with power reserves. This will avoid possible problems with a lack of power.

Usually this characteristic indicated by the value VA or W. If the value is indicated in VA (VA), then multiply it by 0.6 to get the value in Watts that are more understandable to us.

UPS type. I talked about the types of uninterruptible power supply systems above. We came to the conclusion that the most optimal would be a double conversion UPS, but for home needs an offline or line-interactive source would be sufficient.
Battery life. This value is very important, since it determines how long the computer will work without external power. Typically, battery life is set in the range of 5-30 minutes. Please note that at maximum load on the UPS, the operating time without electricity is significantly reduced.

These three characteristics are the most important. In addition to them, the UPS has many more characteristics. For example, when choosing a UPS in a store, pay attention to what power connectors are installed in the source, whether there is a display and additional interfaces (RJ-11, USB), how many batteries are installed, and others.

Frequently encountered problems

The most important problem that most often arises with a UPS is the failure of the battery. A dead battery can be determined by the fact that the uninterruptible power supply stops supporting the load - when the power goes out, the computer immediately turns off. Also, a damaged battery can manifest itself in a different way: the uninterruptible power supply does not turn on at all, or it turns on and beeps continuously. I wrote about how to change the battery in a UPS. It says about a specific UPS, but the replacement principle is practically the same in all sources.
The UPS may not turn on at all due to a blown fuse.
If the uninterruptible power supply starts normally, but the computer does not turn on, then check the wires; they may come out of the sockets.

I hope my article was useful to you and you learned something new. If you still have questions, you can ask them in the comments.