Small and medium-sized server rooms require a high-quality, efficient and reliable backup when the power fails or drops to an unacceptable level. IT equipment is highly sensitive to electrical disturbances, that is why it is important to protect it with a well-chosen uninterruptible power supply.
At Helios, we usually get questions from network engineers to maintenance engineers who ask questions related to size, loading, redundancy, backup time and mounting between others. At Helios, we decided to sit down together with our UPS experts and answer the five most common questions for small and medium-size server rooms, check them out below.
What UPS Should I Use for My Server Room?
For server rooms, rackmount UPS system are very common. However, rackmount systems have limited battery capacity to support the load for an extended time. If the facility has no backup generator then a stand-alone system would work better as it normally has a large internal space for additional batteries.
How Do I Size My Server Room’s UPS?
For IT applications it is a common practice for UPS systems to operate at about 50% (75% maximum) of its total capacity. To size a UPS, just simply add power ratings (Watts from the nameplates) of the equipment together then double it up. This will give you the capacity of the UPS with good headroom. Good quality IT equipment would create high inrush current during start-ups. therefore, UPS needs to have enough capacity to handle that. However, to size the battery banks you’ll need to use the total power rating of the load multiply by 50%, then work out how many and what type of batteries will be required to achieve the runtime. The reason for doing this is not all equipment will draw full power during normal conditions. Constant load normally will be less than 50% (20% even) of the rated power. Although this method will provide a rough estimate of your UPS capacity requirements, for more information, or support sizing your UPS battery system, contact our sales team.
How can I make sure I have enough backup runtime?
When sizing a battery set for a UPS the primary factors to consider are:
- Site power history, and, the duration of previous mains power supply failures
- Critical load sizes
- If there is a maintained standby generator on site
- The length of time required for load shedding and/or an orderly shutdown
- The available environment, for example, space, temperature and humidity
- Cost versus space requirements for longer runtime systems
When quoting UPSs, we normally provide detailed runtime data for the UPS System withing the range of load levels it can support. Most UPS have expandability capability, so external battery cabinet can be added to extend runtime.
Some of our UPS have special EnergyShare sockets that enable load-shedding to extend the battery runtime available for more critical loads: alternatively, emergency loads that are normally not power when mains is present can be activated. Load shedding is common practice to manage potential downtime on networks where there are multiple servers or equipment clusters that need protection.
There are three ways to achieve such a priority-based shutdown:
- Programmable output sockets are available on certain UPS (i.e. EnergyShare sockets on Riello UPS products) . Check on our range of UPS with EnergyShare Sockets
- Intelligent power distribution units
- Using UPS system monitoring and control shutdown software, with each server set to run for different periods of time before shutdown.
How much space do I need?
Single-phase UPS systems up to 20 kVA can be installed in a rack or rack enclosure, so make sure there will be enough open rack units available. And don’t forget to consider the depth of the UPS cabinet. 3-phase UPS systems 20 kVA and above are typically housed in tower cabinets that can be located near the racks or in another room, depending on your preferences. You’ll also need to account for any PDUs, bypass panels, power distribution cabinets, power cables, cable managers and other accessories that you plan to add to your UPS system.
Should I choose a line-interactive or on-line UPS?
Line-interactive UPS are less expensive than on-line UPS systems , but they provide less protection than on-line UPS systems.
Line Interactive (VI – Voltage Independent) UPS operate similarly to an Offline UPS, with the addition of a built-in Automatic Voltage Stabiliser (AVS).
The AVS ensures the output voltage remains within a pre-defined voltage window regardless of any voltage variations on the mains input supply. Most Line Interactive UPS will provide a modified sinewave (more commonly known as a ‘step-wave’) whereas on-line UPS will provide a sinewave output. Line Interactive UPS are typically used in smaller, less critical applications, such as PCs, telephone systems, non-critical networking equipment and small motor loads.
Typically a line-interactive UPS is only available up to 3kVA – however, larger Online UPS will have a specific ‘Line Interactive’ operating mode, which allows an Online UPS to operate as a Line-Interactive. So, for your critical server applications, we highly recommend using On-line UPS Systems.
Server Room UPS recommended by Helios Power Solutions
Below on-line UPS range recommended by our experts for small and medium server applications. Hot-swap batteries, wide input voltage range, power redundancy, automatic bypass, overload capacity and remote communications make this range the perfect solution for improving availability and fault tolerance of your critical network equipment.