Form factor
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Standard (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.
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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 standard of racks is 19", however there are other options, so it would not hurt 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.
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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 heating boile
...rs. 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.Full load operating time
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.
Half load operating time
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.
Switching to battery
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.
Input voltage range
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.
Max. current
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.
Efficiency
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%.
Output frequency
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.
Total battery capacity
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).