free estadisticas Saltar al contenido

The best uninterruptible power supplies (UPS) for Mac, PC and home automation

marzo 24, 2020

UPS stands for Uninterruptable Power Supply, and the acronym identifies the accessories that in Italian are called "continuity group". These are devices used to solve the problem of sudden power failures (due, for example, to a temporary blackout); some models are able to control excessive voltage variations for certain equipment, constantly supplying energy with an oscillation frequency free of accidental variations, perfectly sinusoidal.

Not all UPSs are the same and, below, we will briefly see how to choose them, what features to take into account, better understand what changes from model to model and have a minimum of bases to orient yourself among the many acronyms you can come across.

How to choose a UPS (UPS) for your computer

What is a UPS

In general, a UPS is a device that has the purpose of monitoring and adequately keeping already powered equipment in the event of a failure in the normal electrical supply. This task accomplished in various ways but in general the most common system consists in the use of a battery or supercapacitor park that intervenes instantly in the absence of electricity at the source.

The advantage of a UPS connected to the computer which, in case of absence of electricity, the group intervenes instantly, preventing the computer and the work that was taking place at the time from turning off. The batteries integrated in the UPS allow you to continue working for a few minutes or even hours (autonomy depends on the type of group, the total capacity of the batteries, the state of charge of the latter, the connected load level and other factors) .

In any case, in case of absence of electricity, all groups integrate an acoustic alarm that allows the user to understand when the time is to save the work in progress and possibly close the computer if the blackout continues for too long.

The various types of UPS

As we have mentioned, UPSs are not all the same: there are various types, with more or less interesting functions according to your activity and for all budgets. The continuity groups are broadly divided into three categories (in order of quality / cost):

UPS standby: are the traditional and simplest continuity groups; they merely supply electricity to the computer and intervene in case of need. They typically deliver a regulated voltage and frequency; some models allow you to eliminate the disturbances present on the power supply (independently generating the alternating current at the output) but have the disadvantage of greater consumption than the other types, due to the constant activity of rectifiers, inverters and other elements, addition to that for recharging / keeping in charge of batteries.

Line Interactive UPS: the “line-interactive” continuity groups are on a higher step than those seen previously. These also monitor the input voltage allowing to protect the computer, tolerating continuous undervoltage and overvoltage drops without consuming the limited battery reserve.

This type of UPS are those recommended to allow connected devices to work in stable conditions; they integrate a greater number of components than cheaper UPSs, typically allowing to cover a wide range of variable input voltages (one of the factors that increases the complexity and expense of the UPS). Line Interactive UPS systems are suitable in areas with infrastructural deficiencies, where the AC voltage of unstable line has marked or highly distorted oscillations; however, if these problems occur constantly, frequent use of the battery reduces its capacity, reducing its autonomy and making it ineffective in the event of a long-lasting blackout. Furthermore, even if the batteries are not completely discharged, frequent use can force them to be replaced more often.

Online double conversion UPS: as the name suggests, the double conversion on-line UPSs convert the power supply twice. The alternating current power supply (with its voltage peaks, distortions and other anomalies) is converted into direct current; subsequently the direct current is converted back to AC. strictly regulated by the UPS. The latter can have a different frequency than the input, which is not possible with a line-interactive UPS. If the AC entrance it does not fall within a specific range, the UPS takes power from the battery so that its output is not compromised (all this obviously takes place in milliseconds). Among the advantages of this type of UPS: greater compactness and lightness, advanced functions to adjust the output frequency and perform power factor correction (PFC), regardless of the type of load.

How to choose a UPS (UPS) for your computerSource: APC

How to choose the most suitable UPS?

The choice of the UPS depends on various factors, on your needs and on how much you are willing to spend. If what you are looking for is a simple accessory so as not to lose your job when you use your desktop computer, any UPS, even one that is cheap, does its job. This is true even if you have a home automation system and want to protect your gateway and modem router from power outages: if your system does not report the power outages by itself you could put a no load check on appliances such as the refrigerator for know when and how the current went out. We remind you that in any case for the maximum continuity of operation in this case it would be useful to have a modem also with 3G / 4G SIM which converts the web connection to the cellular connection in case of loss of the fixed telephone network.

If you are looking for a UPS that is able to safeguard your work but also protect the equipment from undervoltages / overvoltages, it will be better to opt for Line Interactive or Double Conversion UPS, able to regulate and filter the power supply, without altering the waveform of the current drawn from the load.

In addition to the type of UPS, you need to understand the power you need, a parameter that depends on the equipment you want to connect to the group. In fact, it is not enough to take into account only the computer power supply but the sum of the consumption of all the components installed inside; the power supply that is present in the computers never provides the maximum possible output but the consumption depends on how many and which components (CPU, video card, RAM, disks, etc.) are used at that time.

Most of the devices on the market indicate the energy absorption in Watts (W), while in the UPS there is an indication of their capacity in VoltAmpere (VA). To get the Watts, yes one, for a conventional value of 70% of the Voltampere: in other words, we need to divide the watts required by 0.7 to obtain the voltampere we need for the UPS to guarantee reliability and correct operation. In the technical specifications of the various computers, you can also find consumption data. On the Apple website you can find the technical specifications with absorption and thermal output of iMac MacBook, MacBook Air, MacBook Pro, Mac Pro and iMac. Here are the links:

For the 27 ″ 2019 iMac Retina 5K, for example, Apple indicates an absorption of 71W if inactive and up to 262W with the CPU active at maximum; by connecting an external disk to this iMac (average consumption 36W) we arrive at a total consumption of (262 + 36) 298 W. A UPS of at least (298 / 0.7) 425 VA will therefore be required. For safety it will be good to round the value upwards, thus reaching an ideal value of 500VA. If you cannot find information on the consumption of the equipment you intend to protect with the UPS, refer to the labels on the devices; these report the maximum consumption and we will therefore have an overestimation of consumption. If you want a precise estimate of the consumption of the various devices you must take advantage of a Wattmetro, accessory (like this) that is installed between the socket and the device and allows you to accurately measure consumption in real time.

Some UPS manufacturers on the sites offer configurators (at this address that of APC): just indicate the type of equipment you want to protect (e.g. a PC, the type of screen, the various accessories, etc.) by directly advising the model best suited to our needs. For a computer like the 21.5 ″ iMac, a basic 500VA UPS is typically sufficient; such a group is enough and also advances to protect modems / routers and network equipment. For higher-end computers – for example, the 27 ″ iMac with various accessories, it will be good to consider a consumption of around 500/600 watts and focus on UPS between 800 and 1200 VA.

For servers and other devices, please contact professionals or companies that deal with UPS, but in general there are specific models for these needs, also in rack configuration. The same goes for protecting multiple machines in the office: typically it is enough to multiply consumption by the number of computers and devices to be protected, also taking into account the various sockets needed to connect all the products.

The EATON Ellipse Pro 850 UPS; here our reviewThe EATON Ellipse Pro 850 UPS; here our review

Other characteristics

In addition to the power supply capacity (vA / kVA), cable length, output connections, other elements that may be important to take into account are: the different type of input connections or the type of "plug" (EC-320 C14, Schuko CEE 7 / 7P, IEC-320 C20); some groups offer protection for the telephone line (useful for protecting the phone and / or a fax) and a USB port for managing power from the computer. By connecting a UPS with USB port to a USB port on the Mac, from the System Preferences> Energy Saver section, it is possible to automatically set the shutdown options.

EATON Ellipse Pro 850, the UPS to the Mac test

macOS offers the possibility to select one or more options to determine when to turn off the system after a power failure; by moving a simple slider you can specify the time or battery level after which the Mac turns off automatically. Finally, in the specifications do not forget to check the noise level: some UPS, when they intervene, could be noisy and annoying to hear; check the level of silence by choosing those that indicate a perceptible 1 meter from the unit surface of less than 50.0dBA.

Not just to protect computers

A UPS at home or in a company useful not only to protect computers but also other: the electronic devices essential for communications, safety and entertainment could be damaged or breakdown due to sudden blackouts, voltage fluctuations and other electrical disturbances. The UPS guarantees protection and backup power for various electronic devices: Wireless network equipment (router, modem, NAS), televisions, security systems, game console.

How much autonomy do you need for connected equipment?

It depends on the type of equipment and other factors. Obviously the greater the number of equipment connected to the UPS, the lower the total autonomy, so it is important that the group only supplies backup power to the most critical equipment, avoiding, for example, non-fundamental areas (laser printers, for example, have peaks that do not recommend connection to the UPS).

How to take care of the UPS

Like other electronic devices, UPSs do not like humid, dusty or particularly hot environments; some models are equipped with fan cooling systems to avoid the premature deterioration of the betteries. On some UPS, specific lights allow you to monitor the status of the batteries and other parameters; other manufacturers make software and monitoring apps available to receive notifications in case of failures. To extend the life of these products, avoid dust, humidity and heat. therefore it is good to install the UPS in a dry place, with adequate ventilation, and with little dust. Do not install the UPS in areas where temperature and humidity have values ​​outside the limits indicated in the technical specifications.

Below we show you a small selection among the many models available on the market: