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UPS for critical systems

How to Select The Appropriate UPS For Critical Systems

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An Uninterruptible Power System is used to prevent any undesirable power features coming via the primary power source from impacting critical loads. These features include various irregularities such as surges and sags, blackouts, outages, transients, brownouts as well as harmonics. Any of these can affect the reliability and availability of your critical loads.

Transient impulses and sags or swells in voltage can hamper the processing of sensitive electronic equipment, permanently harm the systems and cause flickering of lights. Here’s a detailed look at how a reliable and customised UPS can provide protection from a range of anomalies:

Protection provided by customised UPS

#1 Swell/Surge

A swell or surge is a significant rise in voltage that lasts for less than a fraction of a second. These can be caused whenever any large electrical motors or equipment such as HVAC systems are switched off.

#2 Transient

This particular power anomaly occurs in less than 8.33 milliseconds and can take place right through a facility’s electrical distribution system. It can be made up of either a waveform notching (decrease in voltage), or a spike (increase in voltage). A transient can be caused by lightning strikes in the vicinity, utility demand load-switching or even the switching of the utility capacitor banks.

#3 Brownout/Sag

This term refers to a short-term dip (for 8.33 millsec-1minute) in the voltage level. Most of the power disruptions caused in critical environments and commercial buildings are caused by these types of irregularities.

#4 Blackout

This refers to a total loss of power and is also called an outage. Typically any voltage drop below approximately 80 V can be considered a blackout as most large-scale equipment would be able to operate below these levels only for a very short time span.

#5 Spike

This is a significant & instantaneous rise in the supply voltage that typically lasts for 8.33 msec. These are generally caused when lighting directly strikes a high voltage power line. It may also occur when the power supply comes back on from the utility post a blackout. The currents and voltages that are caused by spikes can easily enter your sensitive equipment via data cables, phone or power and can potentially destroy it; aside from this, it can also result in loss of critical data.

Important Aspects

If you want to choose the appropriate UPS for critical systems, it is important that you have at least a basic understanding of what these terms are and what they indicate. Today, there are a number of power protection devices to choose from and these are specifically designed to effectively protect data and equipment from any damage that’s caused by irregularities in power quality, or power outages. A UPS is the commonest type of system used and most of these systems fall under these categories:


Since any critical loads that are directly connected to the main supply are connected via the primary power source such as standby generator or the utility, These offline systems don’t have the ability to provide effective protection from frequency variations, sags, spikes and line noise.

Line interactive

This system provides excellent protection against switching transients & high voltage spikes. Without total electrical isolation (as in the case of a double conversion online UPS system), the common-mode noise passes through to any critical loads.

Online double conversion

Since these systems fix the power supply at the input, they are able to accommodate a significant amount of variation in the supply’s frequency and they are able to continue functioning without having to move into the battery mode.

The company that you approach for your UPS requirement will be able to guide you and provide you all the information you need. If you want to know more about our products and services, don’t hesitate to contact us at KaRaTec Power Supply Pty. You can give us a call at 612 9808 1127. You can also fill in this contact us form.

Thanks for reading,
Karatec Power Supply Pty
612 9808 1127

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