Discover how A UPS can save the day by supplying emergency backup power when the grid fails.

Key Takeaways:

  • UPS systems are important for computer rooms and other areas with sensitive equipment.
  • They’re meant to supply short-term power so there isn’t a sudden outage.
  • They can also cover for short-term power lags.

There are many reasons for businesses to install an uninterruptible power supply (UPS). The less technical (and only slightly exaggerated) explanation is that they’re magic battery-powered boxes that can pause time. Now we’ve got your attention, let’s get serious. This is the ultimate guide to UPS systems, after all.

What does an uninterruptible power supply do?

UPS systems supply practically instantaneous backup power to electrical devices: communication systems, computers, consumer electronics, network equipment, and servers, among other key equipment. A UPS won’t die when there’s a grid failure or power surge. The UPS is connected to the grid, but whereas anything drawing power solely from the main supply will be interrupted, the UPS battery keeps it working.

A UPS also protects equipment from electrical damage and data loss that can occur during a power surge. This is important for any business, especially for data centers. UPS systems also protect against voltage sags and spikes, and harmonic distortions (variations in current and voltage which can cause wires to overheat). Here’s the catch: a UPS only supplies a limited timeframe to close operations safely. How much time you get depends on the type of UPS system you install.

How to make an uninterruptible power supply

A UPS has four central parts: the static bypass switch, inverter, rectifier, and battery. The bypass switch turns the UPS into a safe bridge between incoming AC power and the destination. This can allow the power flow to bypass the UPS entirely and provide electricity even if the UPS fails.

The rectifier and inverter work together; the rectifier turns AC power into DC, which the inverter then switches back into AC (it’ll make sense in a moment). Other important UPS parts include fans and filters, capacitors, and metal-oxide varistors which protect circuits from high voltage surges. Here’s a breakdown of the design and function of common UPS types:

1. Standby

These “lightweight” UPS supply only limited protection against power events and typically the shortest backup times. This makes them best suited to backing up non-critical devices. Standbys switch on their inverter almost immediately at the first sign of power failures, or when power goes above or below required levels.

2. Double Conversion (Online UPS)

These systems are always on and have zero transfer time. It’s ideal for the demands of data centers and the protection of high-end servers and mission-critical IT equipment. This type of UPS is essential to the continuing operation of critical loads in bigger, more data-dependent businesses. You should also consider a commercial generator for twice the backup of your critical loads.

3. Line-Interactive (LI)

This UPS filters incoming AC power and “cleans” it, which simply means scrubbing it of electromagnetic noise. LI systems change their output level according to facility needs, and like double-conversion designs, is always on and charging. LIs support servers, computers, network equipment, and consumer electronics. 

Electrical professionals will help you select the right UPS type. Once it arrives, it’s time to wire it up.

Installing a UPS

First, double-check that no connections are loose in the UPS whether it’s already in use or newly arrived from the manufacturer. Next, the UPS must be properly grounded. The unit needs plenty of space, where ongoing access and future maintenance will be easy.

It’s wise to think ahead and leave some extra space to allow for future UPS scale-up. The temperature and humidity of the installation zone is especially important; UPS capacitors must stay moist with electrolytes; they will dry out if not kept in a cool area. 

Next, link the UPS into the power-distribution system. Input and output AC cables must be connected along with DC battery cables. This can be achieved by elevating the UPS on a sturdy platform (they can be very heavy) to allow plenty of cabling room, or by installing a floor trench. Both are needed with UPS systems that require cabling from the bottom. Some UPS designs will require overhead cable installation because the cables enter at the top.

Each UPS should have an internal-bypass switch for manual operation whenever maintenance, repair, or replacement is necessary. This prevents disrupting the wider system. UPS systems can be ring-wired or radial-wired; radial is best because it isolates power losses to local circuit breakers and provides more  protection against excessive current.

UPS testing and maintenance

Through the wiring and installation process, electricians must pay attention to the UPS manufacturer’s instructions and local/national electrical codes. Proper installation requires a dry run of all UPS functions. Most UPS manufacturers include testing software. Many units will also have comprehensive digital readouts providing at-a-glance numbers and icons that highlight any issues.

Conductance and impedance tests should be carried out a few times a year to check battery health. Both tests can be lengthy; schedule them when they’ll have the least impact on your operations. Keep UPS filters and fans in good condition by regularly replacing and dusting them.

The best for UPS? UES 

We know how to build the right UPS for your business. UES works closely with the best UPS manufacturers; count on quality hardware installed with minimal operational interruption and maximum care for your infrastructure and data. Contact us with any UPS questions or for a free quote!