Unsolved
This post is more than 5 years old
1 Rookie
•
87 Posts
•
16 Points
0
5994
January 18th, 2019 11:00
Determining UPS power rating to use for SME data centre
Hi,
I'm doing datacentre infrastructure for the first time, thus kindly bear with me.
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.
1. Am I correct in understanding that the 550W refers to the power the device uses at any given time and NOT per hour ?
2. I have been seeing UPS from various manufacturers, including Dell, 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.
3. If yes to the above, 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 ?.
4. 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 ?
Thank You
0 events found
Daniel My
12 Elder
•
6.2K Posts
0
January 18th, 2019 13:00
Hello
The rated PSU wattage is how much power it can supply to the system. Some power supplies list peak wattage, peak wattage is not a sustainable output. The wattage listed on our server PSUs is continuous power output, not peak. The PSU wattage(550w) is how much it can supply at any moment, not hourly.
The full load runtime is how long the UPS can supply power at full capacity. If it was supplying the full 1920w then it would run out of power after 5 minutes.
Power supply units are necessary in our servers. It is not an optional component. The uninterruptible power supply is optional. Redundant UPS configurations are not normal, but if you are going for maximum up-time then each of the redundant PSU's would be connected to a different UPS to avoid common points of failure. The redundant PSU will use a small amount of power, even when not in use.
http://www.dell.com/calc/
http://www.dellups.com
You can find system specific documentation on the system support page.
http://www.dell.com/support/
Thanks
phcaptjim
1 Rookie
•
23 Posts
0
November 26th, 2019 08:00
Daniel, thanks for posting that information. It's helpful. I have a similar question and I think I have a handle on this but I want to be sure that this setup would be 'safe'.
Servers:
R710 750w x 2
R710 550w x 2
My plan is to buy two of these:
CyberPower CP1500AVRLCD Intelligent LCD UPS System, 1500VA/900W, 12 Outlets, AVR, Mini-Tower
For the 750w rig, connect one power supply to the first battery backup outlet and one to a non battery backup outlet on the first UPS
For the 550w rig, connect one power supply to the second battery backup outlet and one to a non battery backup outlet on the second UPS
Does that sound like an acceptable solution or is that not wise? I don't need both power supply's on backup but I would like to have one and just have them gracefully shutdown if we have an outage that lasts 1 or 2 minutes.