Comparison Marsriva KP5 vs Tecnoware Era Plus DC

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.

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 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.

- 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.

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 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 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.

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.