How to Determine What Size UPS System You Need!

Are you trying to figure out how to determine what size UPS system you need to protect your equipment?

Making sure you have the right size UPS is key to protecting your equipment; If the system has insufficient capacity to support your equipment, you may not be protected during a power outage or other power-related issues. The closer the UPS capacity matches your load, the more efficiently your UPS system will operate.

There are two major factors to consider: Capacity and Runtime.

Capacity is the maximum power the UPS system can output to support the connected equipment.

Runtime is the length of time the UPS system can support the load level of the connected equipment on battery power. 

For runtime, you will want to figure out how much battery backup you will need before an alternate source of power can kick in or before you can safely shut your equipment/systems down.

Now, let’s go over some of the basic steps for figuring out what capacity you will need!

1. Make a list all equipment to be protected by the UPS. (Remember to include monitors, external hard drives, routers, etc.)

2. Determine the amps and volts for each device listed. (These ratings can typically be found on the label on the back of the equipment.)

3. Now, 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.)

4. Multiply the VA by the number of pieces of equipment to get the VA subtotals.

5. Add the VA subtotals together.

6. Multiply the total by 1.2 to get the grand total. This step accounts for future expansion.

7. Use this 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.