Buying a UPS… it’s not rocket science!

Inevitably, we will receive inquiries for a battery backup system (UPS) from folks that do not have all the necessary information at hand. That’s OK!  Not everyone is versed in UPS systems, and many have other jobs to do. But to put you at ease, it’s not rocket science!

Because we are not all “Pro’s”, it is important to take a step back from time to time and re-visit the basics.

If you are one of the well-trained, technical types- GREAT!  Please share this information with folks in your organization that do not have your skills.  I am sure when the need arises, they will appreciate it!

How to Size a UPS

You have decided that you need a UPS.  What’s next? Well, you must pick the right one!

Alternative #1:

Give us a call/email and we can begin the process by answering some basic questions. or 800.383.6956!

Alternative #2:

Do it the old-fashioned way. Completing these steps is also very useful for the first two alternatives.

  1. List all equipment to be protected by the UPS. (Remember to include monitors, external hard drives, routers, etc.)
  2. List the amps and volts for each device. These ratings can typically be found on the label on the back of the equipment. Multiply amps by volts to determine VoltAmps (VA). Some devices may list their power requirements in watts. To convert watts to VA, divide the watts by power factor. For servers, the power factor is often 0.9.
  3. Multiply the VA by the number of pieces of equipment to get the VA subtotals. 
  4. Add the VA subtotals together.
  5. Multiply the total by 1.2 to get the grand total. This step accounts for future expansion.
  6. Use the grand total to select a UPS. When choosing a UPS, be sure that the total VA requirement of supported equipment does not exceed the VA rating of the UPS.


What else do you need to know?

The size of UPS is just one consideration, in addition it is important to know the following information:

  • Do you need a 3 phase or single-phase unit?
  • What is the needed input and output power?
  • Do you require a rackmount or tower configuration?
  • How much run time will you need?
  • Will you require hardwired or a system with a line cord and receptacles?


Also, there are a few other elements that may be important:

  • Do you need options such as communication cards, bypass switches and/or service elements such as a startup?
  • Is space a concern? If so, we will need to know what your current restrictions are
  • Will you need room for expansion in the future?
  • Do you need installation and/or startup?


Having the correct unit for your situation is so important.  Don’t let hesitation because of lack of knowledge keep you from protecting your valuable equipment.  Give us a call at 800.383.6956 Ext 156 to discuss your options. If you are in need of service on and existing unit or replacement batteries call us at 800.383.6956  Ext 155.