What kind of Uninterrupted Power Supply (UPS) do I need (and why)?

An Uninterrupted Power Supply (UPS) protects connected equipment from power problems. It also provides battery backup power during outages. Some UPS systems also regulate abnormal voltages.

UPS systems protect against downtime, equipment damage and data loss.

Downtime – Blackouts and brownouts shut down equipment. Uninterrupted Power Supply systems supply battery backup power to support equipment through blackouts.

Damage – Surges and line noise can damage internal components in a single devastating event or slowly over time. UPS systems have surge protection and line noise filtering to protect your gear against potential damage.

Data Loss – When power problems shut down equipment, valuable data is often lost. UPS systems allow enough time for your data to be saved.

Types of Uninterrupted Power Supply

There are three main types of UPS battery backup, categorized by how they work: standby, line-interactive and on-line.


Standby provides a basic level of protection from power problems. Standby is also called offline or battery backup. It’s the most cost effective type. The better ones switch to battery fast enough to prevent power anomalies and ride out short outages. A standby UPS protects against most spikes, but doesn’t maintain perfect power during minor sags and surges.

The key to how good a standby unit is, is the range of power the unit will except before switching to battery backup. The wider the range, the less drain on the battery. And, the more backup time available when the power shuts off. The more times the UPS switches to battery backup, the shorter the battery life.

Standby technology will protect from most power spikes by clamping down on excess voltage. It will help ride out more than 90% of all outages. They are best suited for devices under 1500VA such as small offices, personal home computers and other less critical applications.

Line Interactive

Line interactive UPS systems provide both power conditioning and battery backup. In areas that have frequent voltage fluctuations, users should consider a line-interactive UPS instead of a standby model. Line interactive UPS includes a voltage regulator. This adjusts abnormally high or low voltage. As a result, line interactive systems reduce reliance on the battery (unlike Standby UPS systems), lengthening its service life.

When AC input power fails, the unit’s transfer switch opens and the power flows from the battery to the UPS output. With the inverter always on and connected to the output, line-interactive UPS provides additional filtering and yields reduced switching transients when compared to a standby UPS. Line-interactive UPS systems are typically used in rackmount applications below 5000VA.


On-line UPS works very differently. During normal operation, on-line UPS continuously “remakes” input power in a two-step process. First, it converts AC power into DC power, then it converts DC power back into AC. And because power runs through an online UPS continually, output is a perfect sine wave. This type of UPS protects the critical load from virtually all power disturbances, including subtle harmonics and waveform distortion.

This two-step process allows on-line systems to supply connected equipment with the best quality output power available. The quality of power from online UPS is significantly better than that of other technologies.

And, constant double conversion on-line operation completely isolates sensitive equipment from every problem on the AC power line. When it comes to safeguarding critical IT loads, only online double conversion technology protects fully against all these power problems, providing the highest levels of security for networks.

Other factors

In addition to categorizing UPS systems by how they work, there are other factors that might guide your choice. One is it’s output. UPS systems can be ranked by the maximum amount of power (expressed in both VA and watts) that equipment is able to draw from the UPS’s outlets or hardwire output terminals. “VA” stands for “volt-amps.” The VA of a device can be figured by multiplying its operating voltage by its amperage rating. For example, a 120V, 2.5-amp device would draw 300VA from a UPS’s output.

Intelligent Operation – In the line interactive category, there are two subcategories: Those that feature intelligent operation and those that don’t. UPS systems that have intelligent operation include a microprocessor. It allows the UPS to relay more detailed operating conditions through power management software. All on-line UPS systems feature intelligent operation.

Within line interactive and on-line categories, there are two subcategories. They are, those that accept connection of additional internal or external batteries and those that don’t. Those that do, allow users to extend battery backup runtime for critical systems during a blackout.

We hope this short explanation will provide some insight for you in the event you decide to start looking into an Uninterrupted Power Supply for your home or office. Corporate Armor partners with several leading UPS providers such as APC, Tripp-Lite, CyberPower, and others. If you have any questions or just want to save on your next UPS investment, reach out to Corporate Armor now or call 877-449-0458. Thanks for reading!

Uninterrupted Power Supply highlights

Protect against downtime, equipment damage and data loss
Can provide power conditioning
Allow enough time for your data to be saved in the event of power failure