What Are Uninterruptible Power Supplies Used for, and How Do They Work?

Power failure is among the leading causes of data loss worldwide. With technology and connectivity becoming engrained into our everyday lives, outage costs have increased exponentially. In fact, 70 percent of data center outages now cost $100,000 or more. Although the stakes aren’t always that high, businesses of all sizes should be prepared with reliable backup power systems to protect them from data loss at any cost.

What Is an Uninterruptible Power Supply?

An uninterruptible power supply (UPS) is essentially a backup battery for mission-critical electronics. They come in various sizes and configurations, but all serve the same two primary purposes. 

1. Provide backup power in the case of an outage.
2. Condition power coming from the source (such as an outlet) to protect equipment from power spikes, sags, and under/over voltage. 

The UPS plugs into the power source and has a handful of outlets for the electronics it's powering. IT administrators commonly plug power distribution units (PDUs) into UPSs to increase available outlets. Most UPSs are designed to provide power for under 10 minutes, allowing just enough time for either the safe shutdown of the electronics or for the power to come back on. 

Large data centers typically have industrial-grade generators and other large systems for backup power but will sometimes rely on UPSs to provide short-term power to their equipment while their generators boot up. Standard UPSs are most commonly found in environments like computer rooms, network closets, and edge locations.

Types of Batteries

Most UPSs use one of two types of batteries: valve-regulated lead-acid (VRLA) or lithium-ion (Li-ion). Although Li-ion batteries tend to be more expensive, they offer several benefits over VRLA, including a smaller footprint, a faster charge, and a longer lifecycle. Because they can withstand heat up to 40 degrees Celsius, nickel-cadmium (NiCd) batteries are used in locations with very high ambient temperatures. Those benefits extend to Li-ion UPSs vs. VRLA UPSs.

Rackmount UPS vs. Freestanding

Depending on its size and form factor, a UPS may sit on a flat surface (freestanding UPS) or be mounted within a standard 19-inch rack (rackmount UPS). Rackmount UPSs are commonly found in server rooms, small data centers, and edge environments. Freestanding UPSs don’t have a “standard” application. They provide backup power wherever it’s needed. Some UPSs have displays on the front panel that allow administrators to analyze performance and troubleshoot problems. “Smart” UPSs connect to the network so they can be monitored remotely.

What Does a UPS Do?

In simplest terms, a UPS supplies power to IT equipment for a short time, preventing downtime in a brief outage or allowing administrators to shut down equipment. When the UPS is not in use, the primary power supply keeps the UPS battery charged.

Basic UPSs remain in standby or offline mode, automatically connecting the IT equipment to battery power when the primary power source fails. There are also line-interactive and double-conversion (online) UPSs, which offer much faster connection to backup power and a range of other power protection features. We discussed these different types of UPS options at length in a previous post.

How Does a UPS Work?

A UPS continuously monitors the incoming power supply. It automatically switches to battery power if it detects an outage or the power becomes too unstable. When it detects that the primary power source has been restored, it automatically switches back to AC power and resumes recharging the battery.

Depending on the load and the size of the battery, a UPS can supply power for five to 30 minutes. Most UPSs alert administrators through a sound or electronic notification that battery backup has been initiated so they can take action to protect the IT equipment before the battery power is depleted.

Best Rackmount UPSs from Enconnex

While the basic functioning of a UPS is fairly straightforward, there is a wide range of sizes, form factors, and features available. It’s important to choose the right UPS for your use case to maximize your investment over the unit’s lifespan.

Enconnex has leveraged decades of collective experience to develop a line of rackmount UPSs that are highly reliable and have industry-leading features. You can choose from line-interactive and double-conversion UPSs with either VRLA or Lithium-ion (LiFePO4) batteries in a range of power capacities. All are available for quick shipping. View our UPS buying guide to find the right configuration for your environment, and contact one of our UPS specialists to learn more.