Choosing the Correct UPS Backup (Part One)

28th Aug 2014

How to Protect Uninterrupted Power Supply

An Uninterrupted Power Supply (UPS) is an electricity storage unit, meant to provide temporary or short-term backup to electrical devices. It is used to save electrical energy in case of emergencies and critical circumstances. Unlike generators, UPS units cannot produce electricity - they can only save energy. The amount of energy saved depends on the capacity of the UPS unit. Large capacity UPS units are also used to prevent electronic goods from damaging in case of major outages, voltage fluctuations and brownouts. As UPS supplies a constant voltage, it can save devices from high voltage and current peaks. Contrary to general perception, UPS units are not only meant to provide protection to servers, but they are also fit to support an entire network of standalone systems and workstations.


Depending on their operation, UPS units can be broadly divided into three main categories: standby units, on-line units and line-interactive units. Standby UPS units are usually low to medium capacity storage systems that are used to provide backup to servers, workstations and domestic appliances. On-line and line-interactive UPS units , on the other hand, are designed to support industrial equipment. When it comes to reliability and feasibility, standby units are better than on-line and line-interactive systems. However, due to their power capacity, on-line units are recommended for high power and critical systems.


Depending on their type and application, some UPS units can be rather expensive. An easy and effective way to increase the lifespan of UPS units and make them more cost-efficient is to provide them with proper protection. You must make sure that the system is not overloaded, or otherwise, you might come across some serious issues. Overloading the system would not only impact its efficiency but it would also reduce the operation period of the system. Therefore, when you are purchasing an UPS unit, it is important to choose a unit that fits your specific needs. It is considered a good practice to purchase a system with more capacity than needed.

How Much Protection You Need

Most retail UPSs sold nowadays utilize a VA rating to indicate the amount of protection needed for a particular system and the amount of load the UPS system can support. For example, a typical PC with a power supply of 300W would have a standard running pull rating of 200VA. A CRT monitor would also be rated around 200VA. However LCD monitors would typically have a running pull rating much lower than of 200VA – usually about 100VA. When purchasing protection for a system, you must bear in mind that the only units that need to be UPS protected are those that are used to save critical data. For example, printers, scanners etc. don’t save data, so they don’t need to be provided with protection. It’s important to note that less loaded systems work more efficiently than fully or overloaded systems, so to extend the life span of an UPS system, it is recommended to load it to a level of 70-80 percent, instead of loading it up to its full capacity. So, for example if you want a UPS for a desktop PC with a typical monitor, it’s recommended to use a UPS with a rating of 450VA. Here is a quick look at some common VA ratings for standalone workstations:

System VA Requirements
Typical Desktop Computer with CRT Monitor 400 VA - 500 VA
Typical Desktop Computer with LCD Monitor 250 VA - 350 VA
Two Desktop Computers with Two CRT Monitors 800 VA - 1000 VA

For the standalone workstations, standby and line-interactive UPS units like BC Pro, Tripp Lite, VS series etc. can meet the requirements and allow you to operate the UPS without expensive protection equipment.

When you are planning to buy a UPS unit, there are a few things that you need to bear in mind, in order to make a relevant and informed decision. In this short article we touched upon some of them but there are other aspects that need to be covered. If you want to learn some more about this topic stay tuned, as “Choosing the Correct UPS Backup (Part two)” is coming soon.