Critical Power Guides | How Does An Uninterruptible Power Supply Work?

With so much information out there on what a UPS is, it can become a complex topic when we talk about how a UPS works. Simply put the best protection is offered by a double online conversion UPS. This works by switching from AC power to DC power (for use with the battery) then converting this back to AC power to supply the load.

There is more to how a UPS works, and here at P&I, we value honesty and clarity in our industry. There is a cacophony of information online and finding your way through the minefield online can be strenuous. That is why we pull together these critical power guides, to give you all the information you could need in one place.

How does a UPS work?

A UPS works by constantly monitoring the voltage it is receiving from the mains supply. When the supply voltage is unsuitable or lost, the UPS will automatically switch to battery power. The UPS ensures that your devices and equipment are protected from other power issues such as electrical surges, sags and spikes.

How long does a UPS last without power?

The battery power will last for a certain amount of time, depending on the size of the battery and the load that is being drawn from it. Typically, a UPS with internal batteries can last for around 5-10 minutes on its battery power.

Once the mains power has returned or stabilised, the UPS will automatically switch back to using AC power and then recharge the battery.

Should I keep my UPS switched on 24/7?

Yes, in order for your equipment to remain protected and ensure a clean and conditioned supply it is necessary to keep it powered continuously through a UPS. However, it is important to ensure that your UPS and battery are regularly tested and maintained. Testing your UPS and battery regularly will help to ensure that it is working correctly and will be able to protect your equipment in the event of any power issues such as a power outage.

If you have a critical load but do not have a UPS, we recommend that you invest in one as soon as possible. A UPS can be a critical piece of equipment for businesses in the event of a power outage or power problem.

Do I need to reset my UPS?

As with all technology it may be necessary to reset your UPS. Although rarely internal errors may occur which will might require the end-user to reset the UPS in order to ensure the errors are cleared and your UPS is functioning. Always follow the manufacturers instructions fully to reset your UPS or call in an expert UPS engineer to carry this out. 

How long does a UPS last?

A UPS will typically last for more than 10 years. However, this can vary depending on the make and model of the UPS as well as how it is used and maintained. It is often required at around the 6-to-7-year mark that a major overhaul is carried out to ensure optimum performance and efficiency from the UPS.

As previously stated It is important to regularly test and maintain your UPS. There are several ways you as an end-user can ensure your UPS is running optimally, read more in our blog on maintenance here. Due to recent updates with HSE, there is more emphasis on ensuring the correct maintenance of your UPS as well as having the correct information in order for it to operate safely.

If you have any further questions about how a UPS works, or if you would like to know more about our critical power services, please contact us today. Our team of experts will be more than happy to help.