UPS: specifications, types

— Standby. The simplest type of UPS, familiar to most ordinary users. Its main purpose is the ability to “softly” shut down work in case of power problems. When the voltage level is normal, the UPS supplies power to the load from the mains, and when the voltage drops or fails, it switches to its own battery. The resource of this battery is usually small — on the order of several minutes, which is usually enough only to save data. Also, such UPSs can smooth out short-term power surges, however, if such surges occur constantly, this wears out the battery and adversely affects the source itself. Redundant UPSs are widely used in home and office environments, they are usually of low power.

— Smart. A kind of development of the idea of backup UPS; such sources not only provide power in case of a decrease or loss of voltage in the network — they also play the role of voltage stabilizers. The design of such UPSs includes a special regulator (usually in the form of a transformer) that compensates for changes in input voltage and supplies a stable voltage to the output. This allows you to supply constant voltage to the load without the use of batteries, making such blocks well suited for operation in networks with unstable voltage — they not only protect the load, but also do not wear out themselves. Interactive UPSs also mostly have low power and battery capacity and are used to protect individual devices.<...br>
— Inverter (online). Another name is "double conversion". The most advanced type of UPS providing the highest degree of protection. The name comes from the inverter — an output voltage generator that directly supplies power to the load. The inverter itself simultaneously receives power from two sources — from the network and from a charged battery. In the event of a critical decrease or loss of voltage in the network, the inverter continues to supply energy, only from the battery. Such a scheme avoids voltage surges when switching from the mains to the battery (which is a serious drawback of the two types of UPS described above and can even damage the especially sensitive electronics connected to them). Inverter UPSs have the highest power (up to the ability to power an entire building) and can be designed for a three-phase connection (see "Input voltage"), and some models allow you to select batteries of different capacities, depending on specific needs. On the other hand, inverter UPSs are not very efficient, noisy and expensive, so they are mainly used when high power or advanced protection is critical.

— Low voltage. Miniature UPS for low-voltage electronics backup. Mini devices provide a low voltage DC output (typically 9V, 12V, 15V, or 18V). Traditional sockets are not provided for in their design, and you can usually connect one consumer to them. For example, when there is a power outage from a backup mini-UPS, a short-term autonomous power supply is established for the router (for up to one hour), security systems.

— Normal (Tower). UPS designed for floor mounting or placement on any suitable horizontal surface. This “installation” is extremely simple, and it is suitable even for the most powerful and heaviest devices, and therefore most modern uninterruptible power supplies (of all categories) are made in the usual Tower form factor. They are supposed to be placed vertically.

— Rack (in a rack). Models for installation in telecommunication racks. Most of these uninterruptible power supplies belong to the professional equipment segment, designed to power servers and other similar electronics (which are also often mounted in a similar way). The most common rack standard is 19", however there are other options, so it would be a good idea to check the compatibility of the UPS with a specific rack separately. We also note that models of this type are often equipped with legs that allow you to place the device on the floor “sideways” or in a vertical position. Display (if available) in such models may have a rotating design for ease of reading parameters in both positions.

— Wall-mounted. Uninterruptible power supplies, primarily designed for wall mounting. Wall hanging may be the best option in tight spaces. However, such an installation is not the only option - many devices can optionally be installed on the floor. Also note that wall-mounted UPSs are often used for h...eating boilers. The main disadvantage of this form factor is the need to drill into the walls to install an uninterruptible power supply.

- Flat. UPS, structurally assembled in a low, flat housing. As a rule, this form factor allows for several options for installing equipment: the uninterruptible power supply can be installed horizontally or vertically. However, it is the horizontal method of installing the UPS that predominates. In fact, everything depends on the location of the uninterruptible power supply and its dimensions - it would not hurt to clarify this point separately.

— Extension cord. Uninterruptible power supplies that resemble an extension cord in appearance. Structurally, such UPSs consist of a set of sockets in one housing, with the sockets located on the top platform of the uninterruptible power supply. Often, the housing of such UPSs is provided with holes or fasteners for wall mounting.

UPS continuous operation time from a fully charged battery when connected to a load with a power equal to the UPS output power (maximum or effective, depending on the type of load, see the relevant paragraphs for details). For a UPS designed to work with a home or office PC, a time of about 10-15 minutes is considered sufficient, this is enough to save data and complete work. To power servers, it is worth using devices with an operating time of 20 minutes or more.

UPS continuous operation time from a fully charged battery when connected to a load with a power equal to half the output power of the UPS (maximum or effective, depending on the type of load, see below for details). The operating time with such a load is much longer than for a full load, and even in the simplest models it can reach 20-30 minutes.

The time required to transfer the load from mains power to battery power. In standby and interactive UPSs (see Type), a short-term power failure occurs at this moment — accordingly, the shorter the time to switch to the battery, the more uniform the power supply is provided by the source during a power failure. Ideally, the switching time for the traditional 50 Hz AC frequency should be less than 5 ms (a quarter of one cycle of the sine wave). With inverter UPSs, the transfer time is, by definition, zero.

Solar-powered power systems allow you to receive "free" electricity, but the photocells themselves work very unevenly - the voltage varies even during the day, depending on the ambient light (sunny, cloudy or bad weather), and at night it is absent in principle. In such power systems with the possibility of restoring the charge from sunlight, batteries must be used that “smooth out” the described irregularities and store a supply of energy for the dark time of the day. For the same reason, special control equipment must be used to charge such batteries - controllers that are responsible for adjusting the process parameters. The role of controllers is usually played by interactive UPSs (see "Type") of a special design, originally designed for this task. There are two main types of such UPSs and they are classified according to the type of controller used:

- PWM. Devices with support for the so-called. pulse-wide modulation of the charge current, the basic type of solar controllers. The mentioned modulation is used in order to maintain a constant voltage at the input of the battery being charged by changing the current strength - this mode is optimal for charging. After the end of the main charge, the controller switches to low current mode, which prevents battery self-discharge and maintains its charge at 100%. PWM type devices use the simplest algorithms of operation, due to which they themselves are simple and inexpensive, but not very efficient; their use is jus...tified only in regions with a large number of sunny days.

— MPPT. Controllers with MPPT function - search for the maximum power point of the solar module. Such devices are much more complicated and more expensive than PWM, but they use the energy coming from the solar battery more optimally - in this respect, MPPT controllers are 25-30% more efficient. As a result, they pay off faster, moreover, such equipment can be used even in regions with low solar activity.

The input voltage for which the UPS is designed. This parameter practically also determines the type of network — different voltages correspond to a different number of phases:

— 1 phase (230 V). Connection to ordinary household networks of the 230 V standard. It is these networks that are used by most devices powered by uninterruptible power supplies: computers, video and audio equipment, gas boilers, air conditioners, medical equipment, etc. Therefore, the vast majority of modern UPSs are designed specifically for 230 V. At the same time, relatively low-power models can work directly from the outlet, but for devices with a high maximum output power — from 3.5 kVA — a special connection format (directly to the shield) may be required.

— 3 phases (400 V). Connection to three-phase networks of 400 V format. Such networks are used to power powerful industrial equipment, as well as to supply energy from substations to entire segments of the power grid (for example, the entire building). Accordingly, in the case of a UPS, it makes sense to use such an input voltage only in the most powerful models designed for a significant load — for example, an entire data centre, or an industrial workshop with high requirements for process continuity. The effective output power of such “uninterruptible power supplies” is from 4 kW, and the output voltage (see below) can be either single- or three-phase....

— 1 phase (230 V) / 3 phases (400 V). Uninterruptible devices that allow connection to any of the types of networks described above. Most of these devices are, in fact, models for three phases, supplemented by the ability to work also from 230 V. Note that for operation from a single-phase network, such models usually need to be connected directly to the shield, and the output power with such a connection may be lower the claimed maximum (this point needs to be specified separately).

In this case, the input voltage range is implied, in which the UPS is able to supply a stable voltage to the load only due to its own regulators, without switching to the battery. For redundant UPSs (see "Type") this range is quite small, approximately 190 to 260 V; for interactive and especially inverter ones, it is much wider. Some UPS models allow you to manually set the input voltage range.

The maximum current drawn by the UPS. In fact, the current reaches its maximum value only when the UPS is operating from the mains with maximum load power and a completely discharged battery. However, when calculating the load on the power grid, this parameter should be taken into account.

The operating frequency of the alternating current supplied to the input of the UPS — or more precisely, the frequency range of this current in which the device can supply the required power to the load due to its own regulators, without using a battery. When this range is exceeded, the UPS switches to battery mode. The smallest input voltage range is reserved for standby UPSs (see "Type"), the largest for inverter UPSs.

Bypass(by-pass) means such a mode of operation of the UPS, in which power is supplied to the load directly from an external source — the mains, diesel generator, etc. — practically without processing in the UPS itself. This mode can be activated either automatically or manually.

— The automatic bypass is a kind of safety measure. It turns on when the UPS in normal mode cannot supply power to the load — for example, when the UPS is overloaded due to a sharp increase in the power consumption of the load.

— Manual bypass allows you to enable this mode at the request of the user, regardless of the operating parameters. This may be necessary, for example, to hot-swap a battery (see below for details) or to start equipment that has a starting capacity greater than that of the UPS. Technically, it can also play the role of a security measure, but automatic systems are more reliable in this sense.

Some UPSs provide both options for enabling the bypass.

The voltage supplied by the uninterruptible power supply to the main power outlets.

— 1 phase (230 V). The operating voltage used in most types of equipment powered by a UPS: computers, servers, medical equipment, household air conditioners and refrigerators, gas boilers, etc. Accordingly, the vast majority of modern “uninterruptible power supplies” output exactly 230 V.

— 3 phases (400 V). The voltage used for powerful industrial units, as well as for powering numerous consumers — for example, for an entire data centre. Accordingly, such an output voltage is typical mainly for the most powerful UPSs; such devices also require a three-phase power supply at the input.

— DC (constant voltage). DC voltage is used to power a variety of low-voltage electronics. It is typical mainly for redundant mini-UPS.

The maximum output power supplied by the UPS, in other words, the highest apparent load power allowed for this model.

This indicator is measured in volt-amperes (the general meaning of this unit is the same as that of the watt, and different names are used to separate different types of power). The total power consumption of the load, implied in this case, is the sum of two powers — active and reactive. Active power is actually effective power (it is indicated in watts in the characteristics of electrical appliances). Reactive power is the power wasted by coils and capacitors in AC devices; with numerous coils and/or capacitors, this power can be a fairly significant part of the total energy consumption. Note that for simple tasks, you can use data on effective power (it is often given for UPS — see below); but for accurate electrical calculations it is worth using the full one.

The simplest selection rule for this indicator is: the maximum output power of the UPS in volt-amperes should be at least 1.7 times higher than the total load power in watts. There are also more detailed calculation formulas that take into account the characteristics of different types of load; they can be found in special sources. As for specific values, the most modest modern UPSs give out 700 – 1000 VA, or even less — this is enough to power a PC of average performance; and in the most "heavyweight" models, th...is figure can be 8 – 10 kVA and higher.

The effective output power of the UPS is, in fact, the maximum active power of the load that can be connected to the device.

Active power is consumed directly for the operation of the device; it is expressed in watts. In addition to it, most AC devices also consume reactive power, which is "wasted" (relatively speaking) is spent by coils and capacitors. Apparent power (denoted in volt-amperes) is precisely the sum of active and reactive power; it is this characteristic that should be used in accurate electrical calculations. See "Maximum output power" for details; here we note that when selecting a UPS for a relatively simple application, it is quite possible to use only effective power. This is at least easier than converting the watts claimed in the characteristics of the connected devices into full power volt-amps.

The most modest modern "uninterruptibles" give out less than 500 watts. 501 – 1000 W can be considered an average value, 1.1 – 2 kW is above average, and in the most powerful models this figure exceeds 2 kW and can reach very impressive values (up to 1000 kW or more in some industrial class UPS).

The ability to change the output voltage of the UPS at the request of the user. Electrical networks in different countries have different voltages: for example, in the post-Soviet space, the standard is 230 V, in European countries — 230 V. Small differences in appearance may not play a significant role, however, voltage mismatch can adversely affect the efficiency and durability of electrical appliances. Voltage regulation allows you to choose the optimal value, thus providing the best conditions for the operation of electronics.

This parameter characterizes the degree of difference between the AC voltage at the output of the UPS and the perfect voltage, the graph of which has the shape of a regular sinusoid. The perfect voltage is so named because it is the most uniform and creates the least unnecessary load on the connected devices. Thus, the distortion of the output voltage is one of the most important parameters that determine the quality of the power received by the load. A distortion level of 0% means that the UPS produces a perfect sine wave, up to 5% — slight sine wave distortion, up to 18% — strong distortion, from 18% to 40% — a trapezoidal signal, more than 40% — a square wave.

Efficiency (coefficient of performance) in the case of a UPS is the ratio of its output power to the power consumed from the network. This is one of the main parameters that determine the overall efficiency of the device: the higher the efficiency, the less energy the UPS wastes (due to heating parts, electromagnetic radiation, etc.). In modern models, the efficiency value can reach 99%.

The form of a graph describing the changes in voltage at the output of the UPS.

— Pure sinewave. The classic AC voltage graph, this is how it changes in an AC network; The sine wave output means that the UPS has little to no distortion compared to the mains. As a result, such power is suitable for any AC technology, and some devices (for example, audio equipment) generally require an exceptionally pure sine wave. However, this requires rather complex technical solutions, and therefore this waveform can be found in expensive interactive and inverter UPSs.

— Simulated sine wave (approximated). This signal has a shape close to a sinusoid, but the graph line in this case is not smooth, but consists of separate rectangular “steps”. This waveform is provided by most inexpensive UPSs; such devices are inexpensive and quite suitable for powering computer equipment.

The frequency (frequency range) of the AC voltage output by the UPS. For computer technology, the frequency range of 47-53 Hz is considered normal, although the smaller the deviation from the 50 Hz standard, the better. On the other hand, in some UPS models, this frequency can be automatically synchronized with the frequency of the mains — so the power supplied to the load will not differ regardless of whether the load is powered by the mains or from the battery. In this case, a wider frequency range, on the contrary, is more desirable.

The number of outlets connected to the power reserve(battery) provided in the design of the UPS. In order for the UPS to fulfill its main role (providing a backup power in case of power outages), the corresponding electrical appliances must be connected to these outlets. The sockets have a standard shape and are compatible with the vast majority of popular 230 V plugs.

At a minimum, the UPS has 1 or 2 outlets and, in more advanced ones, there may be 3 or more.

The number of outlets without connection to the power reserve provided in the design of the UPS. For devices connected to such outlets, the UPS only performs the function of a surge protector — it smooths out small voltage irregularities; when the mains voltage fails, the power to these outlets is also turned off. The sockets have a standard shape and are compatible with the vast majority of popular 230 V plugs. The presence of sockets without a reserve allows you to connect equipment with different requirements for uninterrupted power supply to one UPS. For example, sockets with a reserve (see above) can include a system unit and a monitor, and a printer can be connected to a socket without a reserve. Thus, if the mains power fails, the computer will continue to work, allowing you to save data, and the printer will turn off, thus saving battery power and providing longer UPS runtime.

A socket for a specific type of plug in the UPS design.

— Type F (Schuko). A traditional European socket with two round holes in the center and grounding contacts in the form of two metal brackets (at the top and bottom of the socket). The term Schuko stuck to this type of socket due to the abbreviation from the German Schutzkontakt - protective contact.

— Type E (French). The French style socket has two round holes and a protruding ground pin just above them in the center. The standard has become widespread in France, Poland and Belgium (along with the traditional type F sockets).

— Type G (British). The plug for such sockets consists of two flat horizontal pins and one flat vertical pin for grounding. The standard is found mainly in the countries of the United Kingdom, Malta, Cyprus, Singapore and Hong Kong.

— Type B (American). American-style sockets are designed for plugs with two flat prongs and a semicircular grounding contact. Type B is widely used in regions with voltage 110 - 127 V - USA, Japan, Saudi Arabia, etc.

Number of C13/C14 connectors with power reserve provided in the UPS design.

Electrical appliances connected to connectors with a reserve are insured against a power failure in the network - in this case they switch to the battery. The C13/C14 connector itself is also known as a “computer socket”; it supplies the same 230 V as a regular household network, but is not compatible with plugs for traditional sockets, because uses three flat contacts. However, there are adapters between these standards.

At a minimum, the UPS is provided with 1, 2 or 3 C13/C14 connectors for one workstation. In more advanced, so to speak office ones, the number of C13/C14 connectors may be greater - 4 ports, 6 connectors, 8 and even more

The number of C13 / C14 connectors without connection to the power reserve, provided in the design of the UPS.

Unlike connectors with a reserve, such connectors do not protect against loss of voltage in the network — for devices connected to them, the UPS only works as a surge protector, smoothing out power surges. This allows you to connect to the UPS devices that do not require continuous power and are not afraid of shutdowns, such as speakers or printers. In the event of a power failure, such devices will not consume battery power, and the UPS will be able to power devices for which continuous power, on the contrary, is essential for longer.

The C13/C14 connector is known colloquially as a "computer socket"; it delivers the same 230 V as a regular household outlet, but is not compatible with conventional plugs, as uses three flat contacts. However, there are adapters between these standards.

The number of C19/C20 connectors with power reserve provided in the design of the UPS.

“With a power reserve” means that when the mains voltage fails, energy from the uninterruptible power supply begins to flow to such a connector. And C19 / C20 is a power connector that allows increased current compared to conventional sockets — up to 16 A. Plugs and sockets of this type have a rectangular shape and three pins (two power pins plus ground); and they are mainly used to power equipment with increased power requirements — in particular, server clusters.

The number of USB A connectors provided in the UPS, designed to charge external devices, such as smartphones or tablets.

This number corresponds to the number of gadgets that can be simultaneously charged. True, it is worth considering that not every UPS with this function is able to charge USB devices from its own battery, without external power supply - it is better to check this possibility before buying.

The number of symmetrical USB C ports in the UPS design, which are used for charging gadgets. Often, UPSs with such an interface are equipped with one USB C output, less often - two.

The terminals are used to connect wires to the UPS — directly, without using any plugs. For models of relatively low power, such a possibility is not needed, but for powerful devices with at least a few kilowatts (used, in particular, for server cabinets), this connection option often turns out to be optimal, or even the only acceptable one. A terminal block is a set of several terminals arranged in a row. Note that the number and purpose of such terminals may be different, this point should be clarified according to the official documentation.

The presence of a DC connector (or several such outputs) in the device for powering external devices with direct current. A standard DC jack is round in shape and has a pin in the center. However, its dimensions may differ in depth and diameter. The voltages output to the DC output may vary.

The absence of a battery in the UPS package — in order to use such a device for its main purpose, the battery will have to be purchased separately. This is associated with additional hassle, but gives such an important advantage as the ability to independently choose the capacity and number of batteries, without relying on the choice of the manufacturer and without the risk of overpaying for the wrong option.

Note that only models that do not have internal batteries and are designed to use external batteries can be supplied in this configuration (see below). These can be both professional inverter models (see "Type"), and inexpensive backup ones.

- Lead acid. Structurally, lead-acid batteries are based on a combination of electrodes made of lead compounds immersed in a liquid electrolyte, the role of which is played by an aqueous solution of sulfuric acid. The advantages of this type are simplicity and low cost, low self-discharge, no "memory effect" and maintaining performance in a wide temperature range. At the same time, the less charge remains in such batteries, the less current they produce. Also, lead-acid batteries are afraid of deep discharges, take a long time to charge, have large dimensions and weight in the context of other types.

- Lead-acid (AGM). An advanced type of lead-acid battery with an electrolyte in a jelly-like state. The gel electrolyte provides maximum contact with the negative and positive plates while maintaining a uniform consistency throughout the volume. AGM batteries impress with their high reliability, low self-discharge, deep discharge resistance and long service life. However, they are sensitive to charge quality, short circuits and negative temperatures.

— Li-Ion. Lithium-ion batteries have a high capacity with small dimensions and weight. They are not subject to the “memory effect”, they are able to charge quite quickly, they can boast of an excellent reserve for charge-discharge cycles. Li-Ion batteries also have disadvantages - first of all, it is sensitivity to low or high temperatures, and when overloaded, such a battery can catch fire or even explode. Howeve...r, due to the use of embedded controllers, the likelihood of such "accidents" is extremely small and, in general, the advantages of this technology significantly outweigh the disadvantages.

Rated voltage of external batteries that can be used in the UPS.

For more information about such batteries, see " Connecting an external battery ", here it is worth saying that the voltage of the external battery must correspond to the voltage for which the "uninterruptible" is designed. If these parameters differ, at best, the UPS simply “will not start”, and at worst, overloads and even a fire are possible.

In general, the more powerful the UPS, the higher, usually, the voltage of the external batteries for which it is designed. However, there is no hard dependency here. And some models even allow several voltage options, for example 96/108/120 V. Also note that a battery with the required voltage can be assembled from several batteries with a lower number of volts connected in series: for example, for 36 V, you can use 3 batteries of 12 AT.

Separately, it is worth emphasizing that the standard voltages for most modern uninterruptible power supplies are multiples of 12 V, however, car batteries cannot be used in such devices. Despite the identical voltage, such batteries are designed for a fundamentally different format of operation, and their use in a UPS is fraught with, at best, incorrect operation of the device, and at worst, fires and even explosions.

The capacity of the battery installed in the UPS. For models with multiple batteries, this is both the total working capacity and the capacity of each individual battery: the batteries in such devices are usually connected in series, so that their total capacity corresponds to the capacity of each individual cell.

Theoretically, a higher battery capacity means the ability to power loads of a given capacity for longer. However, in fact, this parameter is more of a reference than practically significant. The fact is that the actual amount of energy stored by the battery depends not only on the capacity in amp-hours, but also on the voltage in volts; this voltage is often not specified in the characteristics, despite the fact that for accurate calculations it must be known. So when choosing, you should focus on more "close to life" characteristics — first of all, on the directly claimed operating time in different modes (see above).

The value of the operating voltage of one complete battery. In most cases, it is 12 V, UPS with 24-volt batteries is a little less common.

The number of batteries supplied with the UPS.

In general, this parameter is more of a reference than practically significant: the number of batteries is selected in such a way as to provide the desired performance — primarily the time of continuous operation. First of all, it is worth paying attention to such characteristics when choosing.

The number of bays in the UPS chassis that can accommodate additional batteries. The presence of additional compartments will allow you, if necessary, to purchase the required number of batteries, if the capacity of the complete battery is not enough.

The time it takes to fully charge the UPS battery. Note that in this case, this time is calculated according to special rules: not from 0 to 100% of the charge, but from a state in which it is impossible to maintain half the load, up to 90% of the charge. Of course, a full charge will take a little longer. However, this data is closer to practice than the “from 0 to 100%” calculation: the inability to work at half load makes the UPS practically useless, and this condition can be taken as zero, and 90% of the battery is already able to provide a good guarantee in case of a power failure.

Adjusting the charging current provides optimal conditions for replenishing energy reserves in the UPS battery cells. In uninterruptible power supply models with a similar function, a charge controller is installed with the ability to change the output current depending on the battery used. And in some UPS systems, automation can not only initially select the optimal current strength, but also regulate it during the charging process depending on the condition of the battery, providing the most gentle charging mode. This increases the efficiency of the charging process, helps extend the battery life and avoid damage.

The ability to turn on the uninterruptible power supply in the "cold start" mode.

A cold start is a turn-on mode in which there is no external power, and the load connected to the UPS is powered immediately from the uninterruptible battery (which, of course, must be charged). This mode is especially useful in emergency cases — for example, if you urgently need to print a document, but there is no light.

Ability to use an external battery in addition to the UPS's own batteries. Such a battery extends the battery life of the UPS, and its connection is often more convenient than installing additional batteries (for which you have to open the UPS case); on the other hand, the battery makes the device more bulky, because takes up extra space outside.

UPSs with this feature can be supplied with or without internal batteries. Also note that there are models designed to use only external batteries and do not have compartments for internal batteries.

The ability to charge lithium iron phosphate batteries based on the LiFePO4 technology of the same name. Let us recall that the corresponding batteries are characterized by a large number of charge/discharge operating cycles, chemical and thermal stability, low temperature tolerance, short charging time (including high currents) and safety in operation. And in general, such batteries cope with high peak loads without problems and maintain operating voltage almost until discharge.

The ability to replace the battery directly during the operation of the UPS, without disconnecting it from the network and the load. To do this, the device is switched to bypass mode (see "Bypass (direct connection)") or, if there are more than one battery, it switches to another battery. The hot-swappable battery is useful, for example, in the event of a battery failure, or to replace dead batteries with fresh ones if there is no time to charge.

The protection functions provided in the design of the UPS.

— Short circuit protection. A short circuit is a sharp drop in load resistance to critically low values, due to which the current strength increases and the UPS experiences significant overloads that can disable the device and even cause a fire. It may be caused by a problem with the connected device, poor insulation, foreign objects, etc. In the event of such a situation, the short circuit protection system turns off the UPS, preventing unpleasant consequences.

— Overload protection. Overload in this case is the excess of the load power consumption over the output power of the UPS. Working in this mode can also lead to unpleasant consequences up to breakage and fire; to avoid this, a protection system is installed that turns off the UPS when an overload occurs.

— Overcharging protection of external battery. The overcharge protection function prevents the accumulation of excess energy in the battery, from which the UPS operates in autonomous mode. Overcharging is highly undesirable for any type of battery. It can lead to various unpleasant consequences - from deterioration in performance to overheating and fire of the battery. The automatic protective equipment on board the uninterruptible power supply turns off the power after the battery is fully charged. This prevents “extra” curre...nt from entering the battery, which could damage it. This system is convenient in that the battery can be left on charge for a long time without fear of overexerting it.

— Noise filtering. A system that suppresses high-frequency interference in an electrical network — these can be either single voltage surges when turning on and off powerful electrical appliances, or long-term interference from constant sources, such as electric motors. These interferences can adversely affect the operation of electronics connected to the network (up to visible failures); the noise filtering system avoids this. Such systems are quite simple, and therefore most modern UPSs are equipped with them.

— Data line protection. High-frequency interference protection system, similar to interference filtering (see above) — only used not in an electrical network, but in a telephone or wired computer (LAN) network. Such networks are also subject to interference from various sources of electromagnetic radiation, which can cause failures of equipment connected to them: PCs, printers, fax machines, etc. UPSs with this feature have at least two LAN standard connectors (input and output), into which appropriate network or telephone (with RJ-11 connectors compatible with LAN) cables are inserted.

— Emergency cut-off. This connector allows you to connect the UPS to an emergency power off system. Thus, in an emergency (for example, in the event of a fire), the entire room, including and with a power reserve, can be completely de-energized by pressing one button. Without this, the UPS would simply switch to battery when the power goes out and leave the equipment energized, which could lead to disastrous consequences.

— Sound alarm. A system that gives an audible signal in various important situations. It is most commonly used to signal a power outage and the UPS is transferring to battery power. Without a sound signal, this could not be noticed at all (the light is not always on in the room, it goes out when the network fails, the contact in the socket itself may disappear, etc.), which is fraught with a sudden shutdown of the equipment, data loss and breakdowns. Also, sound alarm can be used for other events — low battery, end of charge, bypass on / off, etc.

Fuses are used to protect the UPS from a critical increase in current strength: at the right time, they open the circuit, preventing unpleasant consequences. Today, these types of fuses are used.

— Melting. At a critical current strength, the conductive element in such a fuse melts and opens the circuit. The fusible protection is disposable, after operation such a fuse must be replaced.

— Automatic. Such a fuse has a sensor that monitors the current strength and opens the contacts at the right time. Its main difference from fusible is reusability: after operation, the circuit can be closed again with literally one press of the button on the fuse.

The maximum energy of an electrical impulse in the mains that the UPS is able to compensate. Short pulses with high energy from time to time can occur in almost all networks — for example, due to interference from powerful radiation sources or due to poor-quality operation of lightning protection on power lines; for unprotected devices, such fluctuations can be very harmful. The greater the amount of absorbed energy, the higher, respectively, the level of impulse protectionprovided by the UPS.

Many modern UPSs can be connected to a computer or other special devices. This provides advanced options for monitoring the parameters of the UPS and managing its functions: without leaving the computer, you can monitor the battery status, network parameters, load, enable special modes, apply automatic adjustment, etc. Such a connection can be made according to the following standards:

— RS-232. It's a COM port. Initially designed to connect various peripherals to a computer. Today it is also quite widespread, however, due to its relatively large size, it is installed mainly on stationary PCs.

— USB. A universal port for connecting various peripherals to a computer, the most popular interface of this kind today — at least one USB port has an absolute majority of computers and laptops.

-LAN. A port used to connect to wired computer networks. Models with this interface can often be connected as a network device, which allows, if necessary, to control them from any computer on this network.

— SmartSlot. A slot in the UPS case for installing expansion cards (SmartSlot cards). The development of APC, is used mainly in the devices of its production. Such cards can provide a very diverse set of features: additional connection ports beyond the standard ones (for example, a LAN control port), a web managemen...t interface, support for SNMP, Secure HTTP and other protocols, connection of temperature / humidity sensors, and much more. To date, a wide range of cards is being produced, making it easy to choose a set of additional functions depending on the specific situation. Most UPS models have one SmartSlot, but if necessary, you can use a special expander and install two cards, and the largest models can have two slots as standard.

— "Dry contact". In uninterruptible power supplies, the term "dry contact" refers to a professional interface used to transfer data on the operation of the UPS to specialized external equipment. Such an interface usually has a whole set of contacts (on the order of 10), often in the form of terminals. And the scheme of its operation can be simply described as follows: when certain parameters are reached, the control relay closes or opens a given set of “dry contacts”, on the basis of which the control device receives information about one or another parameter of the UPS operation.

The presence of the UPS own display makes management more convenient. Various operating characteristics can be displayed on the external screen: mains voltage and frequency, operating mode, load level, battery charge, bypass status, etc.

Availability of wheels for transportation in the design of the UPS. This equipment is usually provided in massive devices: carrying such a UPS by hand can be quite problematic, while the wheels allow even a very bulky device to be rolled across the floor without much effort.

The presence of a handle on the UPS case, which makes it easy to move the device by hand. Most often, portable charging stations are equipped with a built-in handle, the very essence of which involves the mobile use of equipment.

Ambient temperature range in which the UPS is guaranteed to maintain normal operation.

All modern "uninterruptible" without problems endure the temperatures typical for residential and office premises. Therefore, it makes sense to pay attention to this parameter if the device is planned to be used in more extreme conditions — for example, in an unheated room, or vice versa, in a production workshop with a high air temperature. At the same time, it's ok to take a margin for temperature: this will give a guarantee in case of unforeseen situations, besides, the wider the temperature range, the higher the overall resistance to adverse conditions.

The maximum noise level produced by the UPS during operation. A noise of 30 dB approximately corresponds to a loud whisper, 40 dB to a conversation at a distance of several metres (it is models up to 40 dB that can be considered quiet UPS), 50 dB is considered the maximum noise level that does not create discomfort. The redundant power supplies are the least noisy, and inverter power supplies are the noisiest (see "Type"). In general, the lower the noise level, the more comfortable the use of the UPS, however, for devices installed in offices where people do not stay permanently (for example, server rooms), this parameter is not critical.

The height of the UPS, expressed in units. This unit is used to measure the height of rack-mounted devices (see Mounting Type) and makes it easy to estimate how much rack space a device will need. Height in unit is always expressed as whole numbers, 1 unit is approximately equal to 44.5 mm.