# Power rating of a UPS

I find it odd that manufacturers specify power rating of Uninterruptible Power Supplies (UPS) in VA instead of Watts since VA doesn't tell you how big of a load the UPS can supply. A case in point is Allen Bradley's 1609-P3000N, where 3000 is the VA rating of the UPS. Had I used power = 3000VA to calculate the load at 120V, I'd have come up with 3000VA/120V = 25A. It was only when I started digging into the spec sheet, I found the Watts rating (2100W). I wonder why the manufacturer doesn't have this rating embedded in the part number since this is the rating you need to determine if the UPS is right for your application (i.e. it can power your load without faulting/nuisance tripping).