What is an Uninterruptible Power Supply (UPS)?

What Does a UPS Do?

An uninterruptible power supply is a power system that provides electricity through a battery backup whenever electrical power fails or drops below the level needed. The UPS will provide enough power for the computer systems to either shut down properly or a different backup power source to kick in, such as a generator. When ever a power outage or power failure happens, it is important that you have your data and equipment protected.

How Does An Uninterruptible Power Supply Work?

There are three different methods of providing surge protection: standby, line interactive and double-conversion.

Standby UPS

A standby UPS is the most common type of UPS. This is often called an “offline UPS”. A standby UPS switches to battery backup during power issues such as voltage sag, surge or blackout.

The standby UPS is often the best solution for home electronics such as security systems, TV, computers and other consumer electronics.

Line Interactive UPS

A line interactive UPS corrects the fluctuations in voltage by interacting with the AC power line. In this configuration, corrections to minor fluctuations can be made without switching to battery power.

A line interactive UPS can provide power during events like over-voltage, voltage sag, surge or blackout.

This type of UPS can be used for entry level servers and other consumer electronics and network equipment.

Online UPS (Double Conversion)

In an Online UPS the inverter provides a stream of continuous power from the battery. This stream of power is consistent and near perfect regardless of the state of the power that is coming in. The power is converted to DC power so the equipment is never receiving power directly from the AC outlet.

These systems are the best and most advanced option for critical IT hardware. Data centers, high-end servers and advanced networking equipment would be protected from damaged caused by voltage surges or blackouts.

How to Choose an Uninterruptible Power Supply

The specific kind of UPS you will need will depend on three different factors: the type of equipment you have, the amount of capacity you need and the amount of runtime you will need once a power event happens.

Equipment Type

The first factor is the type of equipment that you are backing up. In most cases of consumer electronics, such as home computers and security systems, a line interactive or standby UPS would be sufficient.

If you are in need of backup power for larger systems, like a data center or high-end server, you will want to consider a double conversion Online UPS.


The second factor to consider is the load or capacity that you will want your UPS to support. Make a list of equipment that will be supported on the UPS and add up the wattage that each component will require. This will help you determine the total required capacity of the UPS.


Runtime is how long a UPS can provide power to the devices that are attached to a UPS during an energy event such as a blackout. For example do you need enough time for the devices to shut down, or do you need a little longer so that a different power supply such as a backup generator has time to take over.

If you have any additional questions about what UPS or power protection system may be right for you, feel free to contact one of our Sales Consultants at 844.610.5300. or fill out the form below.

Request More Information About a UPS at Your Business
This field is for validation purposes and should be left unchanged.

PC Mag