How to choose an UPS to save your PC

An uninterruptible power supply, or UPS, is, roughly speaking, a large and smart battery that automatically switches appliances to backup power if the main power fails.

All the important equipment in the house is plugged into it. At the same time, you can use it when the mains power goes out and not spoil anything due to voltage fluctuations. Also a good UPS will help to protect against data loss when working on the computer and not sit without warm water if it is heated by a gas boiler with electronics inside.

In the article I will tell you what uninterruptible power supplies are, how they differ and which one is better to pick up for different tasks.

How UPSs work and what types of UPSs are available

Simple uninterruptible power supplies switch the connected device to battery power if there is a problem with the electricity in the outlet. The more finicky the equipment, the more complex and advanced UPS for it is needed.

By design, uninterruptible power supplies are divided into three types:

1. Standby, or offline. The simplest and most budgetary type of UPS. It consists of a battery and a sensor that determines whether the voltage is sufficient to give the outlet. Does not protect against voltage fluctuations and other anomalies of the network.
2. line-interactive. Work in the same way as standby, but better protect against power surges and filter interference that occurs due to network overload, poor quality wiring and a million other factors. The result of interference can be background noise on a microphone recording, flashing lights in a room, or flashes when devices are plugged into an outlet.
3. Double-conversion, or online. These give out the best quality power because the signal in them is converted twice: from AC to DC and back to AC. Thus the devices receive a signal filtered twice, which is protected from interference, surges and anomalies better than in standby and line-interactive models.

UPSs vary in other characteristics as well.

Power is measured in watts, W, and determines how many simultaneously connected devices the UPS can handle when operating on battery power. Sometimes manufacturers write not only useful, but also total power: it is measured in volt-amperes, VA. It can be ignored because it contains "reactive", i.e. useless power, which can be confusing when calculating.

Battery capacity is measured in ampere-hours, Ah. The maximum capacity is stated in the specifications. In reality, it depends not only on the size of the battery, but also on the load on the battery, the temperature of use, and the type of battery.

Noise level is measured in decibels, dB, and can be a problem if the UPS is in a living space. The cooling system in an uninterruptible power supply is humming - under high load it cools the insides of the device.

Full and Half Load Run Time helps you understand how long the UPS will run from the battery without mains power at full and half load. You can calculate this parameter yourself, but this is how manufacturers make it easier for customers to choose.

Signal Quality determines how much clean electricity the UPS gives to connected devices. The "cleanest" signal is called a sine wave, and the "dirtiest" signal is called a meander.

For computer electronics, the quality of the signal is irrelevant. Computer electronics refers to any non-domestic device:

• telephones;
• televisions;
• monitors
• laptops;
• game consoles;
• audio systems.

These have advanced power supplies that clean the signal themselves. But heating appliances, pumps and gas boilers are more picky about the type of signal. 

Why devices care about signal quality

AC current, the kind that flows in an outlet, has a frequency. It is measured in hertz and refers to how the direction of the current changes every second. In Russian and European outlets, the normal frequency is 50 Hz. That is, the current changes direction 50 times per second. That's why it's called alternating.

But the frequency of fluctuations does not say anything about the quality of the network. The direction of the current can change smoothly - this form of signal is called a sine wave. Or intermittently - this waveform is called a meander.

The waveform is important UPS, because not all devices are suitable meander - finicky appliances like boilers and pumps require a sine wave. If the boiler is connected to a budget UPS that produces meander, the mechanical energy will not go into it completely. The excess will turn into a load: the pump in the structure will begin to knock, and moving elements - to warm up more than usual. All of this will greatly reduce the operating life and can lead to failure.

Computers and other modern electronics without motors are not threatened by this - they are equipped with switching power supplies that filter electricity well. You can choose a UPS for your computer without looking at math charts.

Outdated transformer power supplies may not work at all from the UPS battery if it does not produce a pure sine wave. For example, such were in Soviet electronics.

Therefore, for gas boilers, refrigerators, vacuum cleaners and pumps, it is better to buy UPS with the prefix smart or limit yourself to only models with double conversion. They produce a perfect sine wave, because they convert the signal several times, regardless of the power source.

You can do with "crutches" - buy an additional inverter for a non-sinusoidal UPS or include it in a voltage stabilizer. Readers share their stories about pumps, refrigerators and their connection to uninterruptible power supplies in the article on "Habr".

What UPSs are used for

UPSs are not only used in homes: large companies use them to protect data centers and server rooms, and hospitals use them to protect important electronics for operations. You need the right UPS for each task.

For a computer. The simplest household task for a UPS is connecting your computer, monitor, router, audio system, and any other important electronics. This will keep your work running, log off, and safely close programs on your computer if the lights go out.

Computers will be fine with the most budget-friendly standby UPS - these are the ones that don't protect against power surges in any way and simply switch to battery power when the power goes out. The main thing is to have enough power for all devices and enough battery capacity to safely shut them down.

 

The Ippon Back Office 1000 can handle a system unit, monitor and router at the same time. At the same time, it will work for a couple of minutes, which is enough time to turn everything off. It costs 87$

Backup UPS is suitable only for computer electronics. Even if the power of such a UPS allows, do not include in it heating devices, boilers, pumps, printers, vacuum cleaners and refrigerators. They are not suitable for the quality of the signal it generates.

For demanding devices, choose a line-interactive UPS labeled smart or a double-conversion model.

For network stabilization. Even if the power supply to the house is uninterrupted, it may be of poor quality. This is due to interference or network anomalies, i.e. situations where the voltage is too low, too high or constantly fluctuating.

The result of interference can be flashing lights, background noise on a microphone recording, or appliances shutting down. A UPS will solve these problems better than a regular voltage stabilizer. And it will protect you from power outages just in case, too.

Battery size and power for normalizing the current are not as important as the type of device. Only line-interactive UPSs or double-conversion devices can cope with quality signal filtering.

 

The line-interactive Hiper City-1000U will protect against any interference or anomalies, but because of its low battery capacity, it's practically useless in a blackout. It's $53.

When choosing a UPS for a boiler and other appliances with motors, pumps and heating elements, make sure you look for a model with double conversion. You want it to produce a sine wave or a signal close to it. The waveform is always indicated in the specifications.

Electric underfloor heating, boilers and any equipment that heats water with electricity makes no sense to connect to a UPS

It consumes a lot of electricity - even a dozen of the highest capacity batteries on the market will not be enough for a few hours of operation. Therefore, all the advice in this section applies only to gas boilers, underfloor heating and other equipment that heats water with gas, not electricity. It too has electronics - pumps, controllers, control panel and lights. But it uses much less power - like a small monitor or a phone charger.

A UPS for heating a summer house must not only be able to withstand the load and give a quality signal to the devices. It is also important that it should work all the time that there is no light, otherwise you can be left without heating and water. But there may be no electricity for several hours or even days, and in stores you can not find an uninterruptible power supply with such a capacious battery.

 

Powerman Smart Sine 1000 costs twice as much as similar models of the same power. This is the price you will have to pay for a pure sine wave and connection to the UPS of everything you want. It costs $121

Therefore, for gas boilers, water heated floors and other energy-intensive equipment that must work for hours, buy advanced UPS with a port for a backup power source. It can be batteries, solar panels, gasoline generators and anything that produces electricity.

However, it is not necessary to buy a UPS for this task: modern gasoline generators filter the incoming signal well enough and power the necessary devices during a blackout. Their only disadvantage is that in the absence of electricity to backup power you have to switch manually - you can not save data on your computer.

In sum, all the elements for long-term power supply of the dacha are much more expensive than conventional household UPS. For a set that will withstand the daily load of all devices in the country house, you will have to give more than $ 1000.

Do not use car batteries as backup power for a UPS. The voltage that a car battery charges is higher than what a UPS can deliver. If you systematically use a car battery as part of a UPS, the battery will never fully charge.

This seriously reduces the battery life and can take the UPS out of service.

Nevertheless, it is possible to briefly test the UPS on a car battery or use it in an emergency.

For full power supply of a private house. In cottage settlements and SNT the quality of the network may be worse than in cities. In such cases, the whole house is connected to the UPS. This will protect the network at the input from sags and voltage dips and save electronics.

This is the most expensive and advanced solution, just a UPS with batteries is not enough for it. To the scheme usually add GSM-modules for notification of light outages and controllers that switch to the generator when the battery is discharged.

Without electrical installation skills, it is better not to install such complex systems yourself. In stores, ready-made kits with delivery and installation cost from 2000$ - depending on the number of electronics in the house.

How to Calculate UPS Power and Battery Life

The easiest way to figure out how long a UPS will last is to look at the specifications. They indicate how long the UPS will last at full and half load. If there is no such information in the description, you can calculate the battery life yourself. To do this, you need to know the power of the devices and the volume of the battery.

Power determines how many devices can be powered simultaneously if the lights go out. Power is measured in watts.

For example, a UPS with a 600 watt capacity will be able to power a battery at the same time:

• a large TV - these consume about 350 watts in one hour;
• six LED lights - about 60 watts;
• PlayStation 4 Slim - 165 watts.

Choose a UPS with 30 percent more power than you need - this will help prevent overloading when turning on some devices and wear and tear on the battery over time.

For example, the power of a refrigerator in operation - from 60 to 400 watts, depending on whether the compressor is running. But when turned on, the refrigerator draws 1500 watts of inrush current for a couple seconds.

Battery capacity affects how long connected devices will last. It is measured in ampere hours. 

It is virtually impossible to determine how long the devices will last based on the number of amp-hours in the UPS

To know exactly how long a UPS will last on battery power at load, many complex factors must be considered: the efficiency of the entire system, battery wear and tear, the available capacity factor, and the temperature around the UPS.

Sometimes the specifications of electronics include a similar parameter - watt-hours. That is, a battery with a capacity of 200 watt-hours will be able to operate a 200 watt device for an hour.

This parameter is rarely found in UPS specifications because uninterruptible power supplies are mainly needed to compensate for short-term mains losses, not for their long battery life.

It is more reliable and easier to rely on what the manufacturer specifies in the device description itself.

 

The Powercom Raptor RPT-1000AP with a nine amp-hour battery capacity will last less than two minutes at a full load of all 600 watts. With a half load of 300 watts, it will last for ten minutes. It costs $50

You can determine the UPS that will be enough for devices of the right power by using our calculator.

Over time, the battery in the uninterruptible power supply will lose capacity and shut down earlier than it did immediately after purchase. In such cases, calibration will help. It should be performed every six months: on some models it is done with a separate button, on others - only in the service center.

UPS interfaces and connection types

The connectors on an uninterruptible power supply determine how many devices can be connected to it and how well they will be protected from network problems:

1. Euro. A regular Euro socket where any electronics can be plugged in.
2. ICE320. A three-prong plug that can be used to plug in computers and some monitors.
3. bypass outlet. A "bypass" outlet that is not connected to the battery and stabilizers. It is necessary not to build up surge protectors next to the UPS - "unimportant" electronics can be plugged into the bypass. Bypass outlets can be Euro and ICE320 standard.
4. USB Type-B. Allows you to monitor the status of the network in a program on your computer: watch for power surges and remaining battery power. More needed by enthusiasts or in a company with dozens of UPSs that are difficult to monitor individually.
5. LCD screen. Shows battery capacity, charge dynamics and line voltage. In modern models, the screens are customizable.
6. RJ-45 or Ethernet. Protects network equipment such as modems, routers and network cards from power surges.
7. Connector for connecting additional TD50A batteries. "Plus" and "minus" to which generators and extra batteries are connected. Will help when the main battery charge is depleted or in extreme conditions.

Euro

 

ICE320

 

RJ-45

 

USB Type-B

 

TD50A

 

How to choose a UPS for your computer

Any type of UPS will do for a computer and the electronics around it: as long as there is no interference in the network, you can settle for a backup. Computers, phones and laptops have power supplies advanced enough to accept any form of electrical signal.

Therefore, you should choose them by power, battery capacity, connectors and additional functions:

1. Power. An advanced gaming PC consumes 350 to 800 watts of power per hour in maximum load mode. To save and shut down the computer, 500 watts will suffice. A monitor consumes 30 watts per hour. Add 100 watts for other small electronics and charging your phone during a blackout. Total: 630 watts.
2. Battery capacity - more than 15 ampere-hours, so that the UPS can withstand at least a few minutes of work from the battery at full load.
3. From the connectors we need only Euro sockets so that we don't have to look for ICE320 cables. We need two battery-powered sockets, for the monitor and the system unit. For the rest of the electronics we can use bypass sockets, i.e. only with filtering, without battery.
4. Additional features. For the future, it will not hurt to be able to replace the battery. Interference filtering will also come in handy - suppose the microphone in the house often catches unnecessary noise.

 

CyberPower UT2200EI is the most budget-friendly option that meets our criteria: 1320 watts of real power, four minutes of full-load operation, noise filtering, and battery swappability. It costs $115

Be careful when connecting laser printers to computer UPSs. They have heating elements that require clean input like gas boilers and pumps.

With a backup UPS, it's better to plug it into a bypass outlet or a separate surge protector. You can also buy a separate double-conversion UPS, but doing it just for the sake of a printer is a waste of money.

How to choose a UPS for a country house

For demanding to the form of the signal equipment will have to buy more serious devices. Here are suitable or line-interactive smart UPS, or uninterruptors with double conversion.

You can include such equipment in the most budgetary backup models, but at your own risk. Compressors, heating elements and motors in it will wear out much faster if you give them a dirty signal, designed to be smoothed out by the computer power supply.

Power in this case is not as important as battery capacity: the electronics in gas boilers do not consume much light. The main thing is that it can be used for a long time. Here are the parameters by which you should choose a UPS for a country house:

1. Power. Gas boiler consumes about 120 watts per hour, water floor heating - about 400 watts per hour. In order not to sit without light, add to the scheme 10 energy-saving bulbs - 100 watts per hour. Total: 620 watts.
2. Battery capacity. 300-400 amp-hours to last without electricity for at least three to four hours.
3. Of the connectors, only external battery support is important, to connect an external generator to the system.
4. Additional features. Interference filtering and pure sine wave - to make the equipment last longer.

Frequently Asked Questions

How to set up and connect a UPS. Most uninterruptible power supplies are simple plastic boxes that plug into an outlet on one side and connect all available devices to it on the other.

If you don't own a data center and bought a UPS for household use, you don't need to configure it in any way. Just plug the device into the outlet.

As soon as the UPS stops receiving power from the mains, it will inform you about it with a loud beep. In some models, its volume can be adjusted.

How to choose a battery for your UPS. Any model with the right voltages will do. Most UPSs use 12 volt batteries. Choose the number of amp-hours based on how much battery life you need.

How to charge your UPS battery. The unit will do this automatically as soon as the mains voltage is restored. Small backup type UPS batteries are fully charged in 8-12 hours. In large assemblies, this time can go up to several days. Therefore, if the light is cut off often and systematically, look closely at backup power sources. For example, gasoline generators.

Briefly: How to choose a UPS

Decide what you want to plug into the UPS. For computers and computer electronics, a basic standby UPS will suffice. Heating devices or appliances with pumps inside require a higher quality signal - for them, buy line-interactive UPSs or double-conversion UPSs.

If you connect heating and other demanding equipment to an ordinary standby UPS, the parts will wear out faster and make more noise.

Line-interactive UPS will also be useful for a computer - if the network is interfered with, the voltage jumps or is constantly elevated. Such uninterruptible power supplies filter the input signal better and will help to get rid of, for example, background noise on microphone recording.

Determine the power and battery capacity. Power is measured in watts and determines how many devices can be connected to the UPS at the same time. To be sure, add 30% to the total power to compensate for the high load on the grid when some electronics are turned on. For example, a gaming computer, monitor and speaker system will have about 800 watts of power.

Capacity is measured in ampere-hours and determines how long the devices will last from the battery. For 5-10 minutes of computer operation, nine ampere-hours of capacity will be enough, and the entire apartment can be powered for several hours with a 50 amp-hour battery.

• • Understand what connectors are needed.** Relevant only if you buy a UPS for a computer. USB will come in handy if you want to monitor the state of the network and analyze failures. Euro sockets can be used for any electronics, while ICE320 sockets can only be used for computers and some monitors. If you want to protect your router as well, choose a model with an RJ-45 connector.