Welcome to 4D's guide to UPSs. Even if you've never heard of them before, by the end of this guide, you'll be able to join in on technical conversations and make informed decisions on how best to deploy UPSs. 

Power failures can cause irreparable damage to your IT equipment and your reputation if your network experiences significant downtime. Understanding UPSs is a crucial part of avoiding these issues. 

We're going to teach you all about UPSs and put it in context so you can see for yourself what's best for your IT set-up. 

Why should you listen to us? 

4D Data Centres has been operating for over 12 years, and through our rigorous testing and maintenance regimes, we’re very proud to say that we’ve never had a power failure. We've been able to achieve this through expert deployment of UPSs, and we've distilled our experience and knowledge down into this guide. 

Before we start: a quick explanation of Comms Rooms, Server Rooms, and Data Centres

Most companies will have a comms room or a server room to look after their in-house servers. A data centre effectively does the same thing but on a much larger scale. While some companies have their own data centres, (often referred to as ‘enterprise data centres’) , smaller businesses may decide to outsource this function to multi-tenant data centres, otherwise known as ‘colocation data centres’.

What is a UPS?

UPS stands for Uninterruptible Power Supply, and it’s a system that sits in between your servers and the mains electricity. To explain how UPSs work, think of them as being similar to the batteries that you’d find inside your laptop. If you’re at home working on your laptop, and somebody pulls the power plug out of it, then the laptop should carry on running. This is because the laptop isn’t running off the mains – it’s being powered all the time by the battery within it. When you plug in a laptop, you’re effectively trickle-charging the battery.

What Are The Different Types Of UPSs?

Modern data centres will typically use one of three different types of technology:

•    Fuel cells

•    Rotary UPSs

•    Battery UPSs

Fuel cells are the most modern type of technology, and as the name suggests, they work by converting chemical energy into electricity. Fuel cells typically use hydrogen to create an electrical charge through a process called ionization. The use of hydrogen means that the only waste product from fuel cells is water, and they are very efficient, with very little heat waste. However, since they are so modern, they can be expensive to install, and the hydrogen needed to run them can be pricey as well.

Rotary UPSs, also known as flywheel UPSs, have been around for quite a long time, used in things like spindles and potter’s wheels. In modern-day data centres, they work by spinning a steel or carbon fibre coil incredibly quickly, and then the kinetic energy is converted into electricity when needed. Rotary UPSs are typically very reliable, easy to maintain, and provide somewhere between 10 and 30 seconds worth of electricity.

Battery UPSs can be subdivided into two groups: lithium-ion batteries, and lead-acid batteries. Lithium-ion batteries are the batteries found inside smartphones, and, they’re typically between 50 and 80 percent smaller than lead-acid batteries. They can also be power cycled many more times, up to a thousand times versus 200 to 400 times for lead acid batteries. Lead acid batteries have been around for longer, so their reliability record is better. But the most important difference between the two is that lead-acid batteries are a lot cheaper than lithium batteries, so they’re the preferred battery of choice for most data centres.

Of the three different types of UPS companies that own and operate server rooms will typically opt for a battery UPS configuration.

Why are UPSs critical?

UPSs are there primarily to provide continuity of power when there’s a mains failure. Within data centres, they provide power until the generator(s) can get up to full speed and take over from the mains electricity. Within a server room configuration, if you don’t already have a generator in place, then UPSs will typically be designed to run for 30 minutes. Usually, this will give a server administrator time to log in and do a controlled shutdown of the servers.

UPSs’ secondary, but still important, function is cleaning incoming mains power, and preventing any fluctuation from affecting the servers.

What are the Pros and Cons of using a UPS in a Server Room versus using one in a Colocation Data Centre?

Having your own server room means you get to decide the size and specification of the UPS, and you have complete control over the maintenance and running of it.

However, there are significant advantages of outsourcing it to a data centre. Operating at a larger scale allows for increased efficiency and resilience.

Data centres are designed to house hundreds of racks and thousands of servers. So they build their UPSs with resilience in mind. Typically they will have more than one UPS, with at least one UPS per feed. They’ll also often have an extra UPS per feed, so that if there is an issue with any UPS on a feed, then they’ve got one to fall back on. This is referred to as M plus one, meaning you’ve got a system in place capable of supporting the data centre, and one additional redundancy.

A UPS within a data centre will typically be a lot more efficient than one in a server room, reducing the environmental impact of your servers since increased energy-efficiency means a greener operation. It also, over time, saves a considerable amount of money regarding the cost of electricity.

Finally, the main advantage of using a data centre UPS rather than buying one in the house is cost. When using a colocation facility, there is no capital expenditure associated with using a UPS as it’s already part of the data centre. This is very good compared to the significant maintenance costs associated with running your own in-house UPS. For example, over eight to ten years, a lead-acid battery UPS will have to have all of its batteries replaced. You’ve also got to have annual maintenance check-ups on the UPS. All of this is covered as part of the cost of colocation data centre facilities.

How much do UPSs Cost?

As mentioned earlier, UPSs and colocation data centres are already built out. That means costs like testing and maintenance, and replacing components such as batteries and capacitors, are already factored into the monthly rental cost of the rack itself.

If you want to protect the servers in your server room, you’re going to have to buy an individual UPS for each feed. Typically, a 4KVA UPS will cost around five thousand pounds. If you want to protect both the A feed and the B feed, you’re going to have to spend about 10 thousand pounds.

Do I need a UPS?

In summary, if maintaining uptime on your IT systems 24/7 is important to your business, then having a reliable UPS is going to be an absolute necessity. Getting the UPS you need can be expensive and difficult to deploy in-house, and colocation might be the best option for you.

If you’d like more information about how 4D can help keep your company online 24/7, then you can find out more here, or get in touch and ask one of our experts for advice.