Five Key Steps to Sizing a 3-Phase UPS Backup System

UPS System Sizing

Businesses from nearly all industries invest in a lot of equipment to support their operations – from sensitive medical equipment, to computers, servers, manufacturing equipment and much more. To protect both valuable equipment and operations, many businesses look to integrate an uninterruptible power supply (UPS) into their backup power solution. In the event of an interruption to the utility or primary power source, whether it be a brownout, blackout, or other interruption, the UPS system will be there to automatically provide emergency power to protect valuable equipment and help businesses maintain operations. But for a UPS system to work properly there are a lot of detailed specifications that need to be correct – from the size in kVA, to the amount and type of batteries, to designing the proper operating environment and physical space. The process of determining these specifications, as well as coordinating the installation, testing, and ongoing maintenance of a UPS system can be daunting, but we have broken the process down into five key steps.

Here are our five key steps to properly sizing a 3-phase UPS system:

1. Identify the electrical equipment that needs to be protected by the UPS

The first step in sizing a UPS system is to determine which pieces of equipment need to be protected by the UPS system. This could be sensitive electrical equipment, computers, servers, emergency lighting or manufacturing equipment. One of the main goals of the UPS system is to eliminate the possibility of damage to equipment should there be a power outage, and to allow a period of time to safely shut down the equipment manually. Any equipment that could suffer damage during a sudden power outage should be protected by the UPS, as well as any emergency systems or lighting that are required to perform the shutdown processes.

2. Identify load type and power requirements for equipment, calculate total load, and determine needs to accommodate future growth

The second step in sizing a UPS system is to determine what the continuous load and starting load levels are. A qualified electrical engineer can determine the total power draw and inrush/starting current for each piece of equipment. This can be done by looking at the specifications data stickers on each piece of equipment, or as part of a complete power study of the facility. The combination of a power study and data sticker information provides the most complete analysis of the parameters. It is also important to consider future growth plans and to plan for the additional power that will be required, whether that be space so that additional UPS systems or batteries can be added in the future, or with an oversized system that will automatically be able to handle future growth.

3. Determine UPS runtime requirements

Another important factor in the overall UPS system is the runtime requirements, or how long the UPS system will provide critical uninterrupted backup power. This commonly ranges from 5 minutes to 15 minutes but can vary for every business. The UPS runtime should allow enough time to safely shut down all critical equipment, or until a backup generator kicks in to handle the load. Longer run times are possible but may require additional batteries and battery cabinets, so this is an important thing to consider as it can significantly affect cost and space requirements. The use of lithium-ion vs VRLA batteries is another consideration, each technology has features and benefits that are important to understand. Battery technology can have an effect on initial cost, space requirements, maintenance and the future battery replacement schedule.

4. Identify available space to install UPS and consider operational environment conditions

The next step is to make sure that the facility has the available space to install the required UPS system(s) as well as the air handling equipment that will maintain the optimum operating environment. The UPS system heat rejection rating, which varies from one UPS manufacturer to another, is an important factor in determining the overall air handling requirements. Choosing a brand of UPS with the most beneficial heat rejection rating can minimize the need for supplemental air handling equipment. Typically, the top-of-the-line UPS systems are going to have the highest initial investment, but will have the most ideal heat rejection rating, as well as be the most efficient and affordable to operate over the long term. Side note: The top UPS manufacturers also have the best reliability and the longest overall lifespan.

5. Choose a company that specializes in UPS systems

When it comes to implementing a UPS system for your business, choose a company that specializes in UPS systems. There are many different UPS manufacturers, and the products all have different features and benefits. Finding a company that understands these differences and can recommend a product that best fits your application can be invaluable and give you the best performing and most reliable product for your money. Many UPS installations require professional engineering reviews, studies or services, finding a company that can offer engineering services as well as installation and maintenance can really help simplify the complexity of the project.

If you are considering a UPS system to protect your business, Global Power Supply is here to help. We are experts in providing high-quality emergency backup power systems for businesses nationwide and we specialize in UPS systems.

Please contact our experienced sales team with any questions, quote requests, or expert advice you may need. Request a formal UPS integration study from Global Power engineering services.