Comparison 2E 2E-ED650 650 VA vs FrimeCom VP-600 600 VA

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.

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 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.

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.

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 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 type of battery installed in the UPS.

— Fiberglass (AGM). An advanced type of lead-acid battery with electrolyte in an adsorbed state: the compartments of such a battery are filled with porous material, which contains acid. At the same time, the battery case is sealed and AGM models are maintenance-free. This technology is the most popular in batteries for uninterruptible power supplies: it is ideal for batteries operating in buffer mode (that is, when they rarely need to be discharged and, as a rule, little by little). In addition, it provides a long service life, and AGM batteries are inexpensive. The disadvantages of this option include the impossibility of replenishing the electrolyte if it leaks, as well as poor tolerance to overcharging (although the latter becomes irrelevant with a high-quality power controller).

— Gel (GEL). A type of lead-acid battery that uses a gel electrolyte. GEL batteries are best suited for operation in cyclic mode - that is, when the battery needs to power the load for a long time, discharge almost to zero, then charge and again provide long-term autonomous power. But for the buffer mode, in which most UPSs operate (standing on standby for a long time in order to briefly maintain power supply in the event of a failure), this technology is not suitable for a number of reasons. Therefore, it makes sense to purchase such batteries only in cases where t...he “uninterruptible power supply” has to be turned on almost every day - for example, in unstable networks with constant and long-term power outages.

— Lithium-ion (Li-Ion). The key advantages of lithium-ion batteries are high capacity with small dimensions and weight. Also, Li-Ion batteries are not subject to the “memory effect” and can charge quite quickly. Of course, this option is not without its drawbacks - first of all, it is sensitive to low and high temperatures, and if overloaded, the lithium-ion battery can catch fire or even explode. However, thanks to the use of built-in controllers, the likelihood of such “emergency” situations is extremely low and, in general, the advantages of this technology significantly outweigh the disadvantages.

— Lithium iron phosphate (LiFePO4). An advanced modification of lithium-ion batteries (see above), designed to eliminate some of the shortcomings of the original technology. Lithium iron phosphate batteries are characterized by a large number of charge/discharge cycles, chemical and thermal stability, low temperature tolerance, short charging time (including high currents) and safety in operation. The likelihood of an “explosion” of a LiFePO4 battery when overloaded is reduced to almost zero, and in general, such batteries cope with high peak loads without problems and maintain the operating voltage almost until they are fully discharged.

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.

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.