I'm doing this the first time.
I'm trying to understand what power rating of a UPS to use, the scenarios is that I will have 4 Dell PowerEdge R440 rack servers, each server has a Dual Hot Plug Redundant Power Supply (1+1) 550W. Furthermore, I need to add UPS with redundancy to this.
- Am I correct in understanding that the 550W refers to the power the device uses at any given time and NOT per hour ?
I have been seeing UPS from various manufacturers, I have used their calculators as well.
- One UPS site mentioned Full Load Runtime of UPS (5 min, 1920W) what does this mean, is this the total Watt power it can provide at any given time, if yes, So in my case each server is 550W, meaning that 550 x 4 (+2 for future growth) servers = 6600W in total, so am I understanding correct that I need to look for a UPS that has a power rating higher than 6600W per UPS (2 for redundancy), that will have a 10 minutes of backup time to allow for equipment shutdown time ?.
And also where does a PSU come into the picture, is it needed, I know that PSU converts AC to regulated DC, but is it needed for my scenario ?