1

I planning to put a server on this ups (Europe, 230V):

http://www.apc.com/resource/include/techspec_index.cfm?base_sku=SUA5000RMI5U&ISOCountryCode=gb

My server has a relatively new energy saving power 700W power supply. I checked it with energy meter and it only consumes ~ 220W on average. Right now it is on a cheap 1500VA centralion ups which I know for a fact that cannot survive more than 10-15 minutes and when it depletes the batteries the charge time is more than 24 hours...

Here in the specs looking at the graph, APC claims that this UPS could power my server for 173 minutes, that is 2.8 hours. Also they claim that battery charge time is only 3 hours !

Can this be true? I never saw ups capable of bridging that time period. Somebody who actually owns one of this would be nice to comment.

Thanks!

pluto73
  • 29
  • 1
  • 4
  • As with all vendor supplied numbers, a marketing department likely has had a say in them and your real world mileage may vary... – HBruijn Aug 17 '15 at 08:58

2 Answers2

3

Can this be true? I never saw ups capable of bridging that time period.

You have not seen a lot, right? It is unusual, but not unheard of.

My own data center is right now mostly shut down. Pretty much 16 machines out of 23 are down due to software upgrades. My UPS - a 20kva unit - tells me up-time is now nearly 8 hours. Under full load we talk of about half an hour capacity.

It is all and ONLY a factor of battery capacity and used load. It is UNUSUAL to have a UPS that handles large time frames, but that is mostly because it is cost inefficient. A UPS should normally handle small outages (hey, fuse went out and back in 30 seconds later) and then have enough reserve to handle the backup generators starting (or, like in our case, safely shutting down the HPC cluster until power is back). IF we would like to keep that running during longer outages, we would install a diesel or two - a LOT cheaper than handling tons of batteries. Our little monster right now has 300kg batteries attached.

But stating "never seen" really is like "I have not seen a lot". Generally - especially if you leave small end user stuff -battery capacity is quite scalable.

In your case you are going to put a much smaller computer to a UPS that is oversized. Yes, the result is a long runtime, much as we have it now.

And it also CAN load quite fast - because that is the normal use case. Noone wants to wait a week for the UPS to reload. That said, depending on load you may want to check your cabling - although even in your case, 1500VA is not really that much. We still talk small units.

TomTom
  • 51,649
  • 7
  • 54
  • 136
1

Its simple electronics, if your server only consumes X over 1 minutes but the UPS batteries contain 173X then yes it will run for that long. However be aware that 'average' consumption is only average for our own statistics, it still peaks high under load etc and must take PSU efficiency into account.

APC graphs and stats are usually pretty good to go by. I would also assume that you are expecting long windows of mains power loss (1 hour+)... Usually UPS's are deployed to protect against minor blips or the switchover period between mains and generator switchover... Or allow equipment to be gracefully shutdown if mains power is lost suddenly.

tomstephens89
  • 1,011
  • 1
  • 12
  • 24