Purchasing a new UPS Backup

Hello all,

We are purchasing a new UPS for the companies network and I am looking for some advice. From the research I have done, it looks like I need to find the volt amps (Volt x Amps) of each device that will be connected to it. After that I have learned that it is smart to add them all together and multiply that number by 1.2 in order to leave room for growth.

My question to you is, am I supposed to use the AC or DC Voltage in the equation Voltage x amperage? I originally used the AC math and it ended up being a much higher volt amp than I anticipated.

This link is where I received my original advice from https://www.tripplite.com/products/ups-sizing

Any advice would be much appreciated.