How to choose a UPS?

Conventionally, there are three levels of protection that are provided by different series of UPS models:

• basic - allows to avoid the most dangerous manifestationsinstability in the supply network. These are single pulses with a large amplitude, but very short duration (for example, lightning discharges or arcing of bad contacts in electrical wiring), periodic power outages at substations -bottom or as a result of an accident), daily fluctuations in mains voltage due to load changes at different phases;
  
• Improved protection - allows further filteringradio frequency and other electromagnetic interference, both in the input network, and interference generated by the UPS itself. Thus, the compatibility of electronic devices in their joint operation is improved;
  
• absolute protection - guarantees getting rid of all possiblefaults in the mains supply, moreover it stabilizes the value and corrects the power factor and the shape of the output voltage, thereby significantly prolonging the life of the connected equipment.

What criteria should be followed when choosing a UPS in the first place, what technical parameters should be taken into account?

In the general table, the spheresUPS applications and three levels of protection. The table shows the most important characteristics, such as technology, power, the shape of the output voltage and the corresponding level of protection.

Naturally, an important role in the selection is played byother technical parameters of the UPS: battery support time, interface port and interaction with the software, the ability to increase the backup time by connecting external battery packs, the presence of electronic and / or manual bypass (bypass), the input voltage range without switching to battery power, time of transition to batteries, overall dimensions, weight, design.

In the description of each model, the corresponding section details these characteristics.

When choosing a UPS, you should also take into account the power supply characteristics and technical characteristics of the equipment to which the uninterruptible power supply is to be connected.
The table will help you make a preliminary selection of the device, depending on the scope and the desired level of protection.

Table of assignments and applications of the UPS (for example, UPS Powercom)

Protection level	Technology	Output waveform	Power	Scope of application
absolute	On-Line		10-200 KVA	Centralized systems of guaranteed power supply, industrial equipment for continuous technological processes, equipment for the military industry, for computing, situational centers, medical devices life support, etc.
			10-20 KVA
			6-15 KVA	Responsible telecommunication and network equipment, medical diagnostic equipment, control and automation devices, audio-visual equipment, centralized, clustered servers, workstations, groups of computers, etc.
			700 VA-20 KVA
improved	Line - interactive		600 VA-5100 VA	Workstations, servers, computer groups, telecommunications equipment and communication systems, commercial equipment, cash registers, fire and burglar alarm systems, emergency lighting, etc.
			800 VA-3 KVA
			425-2000 VA
basic	Line - interactive		400-2000 VA	Personal computers, computer peripherals, light network equipment
			400-1000 VA
	off - line		300-700 VA	Personal computers, computer peripherals, faxes, DVD, audio equipment, telephones, modems, etc.

Based on the materials of the site pcm.ru