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.
Bypass (direct connection)
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.
Peak output power
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.Rated output power
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).
Output waveform
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.
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.
Reserved C13/C14 connectors
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
Reserved C19/C20 connectors
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.
Number of batteries
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.
