• Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
    Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.

ups beginner

R

rockdragon

Weaksauce
Joined
Jul 27, 2005
Messages
100
My bosses have finally listened to me and have decided to get a ups for our 4 servers. 3 of them will be in a separate room. The total wattage for those 3 is approx 2000. The last one is 600w.

Now this is the first time I have ever started looking into a UPS. I have no idea what kind of voltage input/output I should be looking for, or what VA is required. All I know so far is that the wattage for the UPS should be greater than the total watts for all the computers, I think.

Does anyone have any useful links I can read through to give me a rough breakdown of that information, or maybe some tips or tricks? So far all I have under my belt is wiki.. so any help would be greatly appreciated.

Thanks
 
DCmod said:
pretty good calculator I used when I bought mine;
http://www.csgnetwork.com/upssizecalc.html
Click to expand...

I have heard that on average you don't want to exceed about 2/3 of the capacity of the UPS. My machine draws about 600 watts on full load so I went with a 900 watt model. According to that calculator that is pretty close to the minimum that it recommends.

I can't imagine running servers without them. We have a separate UPS for each server and a backup generator so that they never go down. Not a cheap setup but when you run Web and DB servers that can't go down there is no other option.
 
Do you guys think it would be better to get a different UPS for each server then? Or would it be better/cheaper to get one powerful one?

And does anyone recommend any brands that are good or that I should avoid?
 
I put a single 1000VA to 1500VA for each server I have at work. This will give me about 30 minutes runtime.

I have heard that on average you don't want to exceed about 2/3 of the capacity of the UPS
Click to expand...

I try not to exceed 1/4 of the capacity. But that is because I want more than 5 minutes of runtime..
 
drescherjm said:
I try not to exceed 1/4 of the capacity. But that is because I want more than 5 minutes of runtime..
Click to expand...

Power capacity and runtime are not dependent. Different UPS with the same power capacity can use different battery types and have far different runtimes.

The most important question is this: What voltage do you use? 120v? 240v? 208v (unlikely)?

I'd go with an APC SmartUPS or Liebert GXT2... A 3000VA won't be enough for the larger room so you can go for a 5000VA or 2x2200VA or 2x3000VA or 3x1500VA. Go for a 1500VA in the smaller room.
 
Last edited:
They are all running at 120v.

Do UPS's put off a lot of heat? If so, is the heat regular, or is it only when its providing power from the batteries?
 
You should be looking at online UPS which means they are always converting power (so that there is no blip in power if/when the external power fails). They will always be making heat which will depend on the load, mainly. They will make a bit more heat on battery due to the higher load on the batteries.

They are around 85-90% efficient so expect them to make around 15% as much heat as your servers.
 
I was running a 1500VA UPS for a server that loaded at around 450 watts (I believe it was) and lasted 30mins under load. Our new one runs around 650 Watts and can run for about 10-15 Minutes under full load.

The bigger UPS the better off you are going to be. Servers need the time to shutdown if it is an extended power outage. Our old server could take 30mins to shutdown.
 
It's not the power capacity of the UPS, but the capacity of the batteries connected. And he can get an extra battery pack if he needs more uptime... if he gets one of the models that allows for it. All GXT2 models do. APC SmartUPS has models that can and models that can't - you want one with "XL" in the model number if you want that capability.

A bigger UPS usually comes with larger/more batteries than a smaller UPS in the same product line, though, so the 5000VA model should indeed have more runtime than a 3000VA model... but the price difference could add extra batteries for cheaper.
 
Last edited:
So I have been doing a little more research, and it looks like there are specific requirements for a PFC power supply. The a PFC power supply needs a UPS that uses true sine waves, where a non PFC can use a simulated sine wave UPS.

Do I understand this correctly? And so does this mean that a PFC power supply will not work on a simulated sine wave UPS at all?
 
rockdragon said:
Do I understand this correctly? And so does this mean that a PFC power supply will not work on a simulated sine wave UPS at all?
Click to expand...

No. PFC powersupplies work even on the worst "simulated" sine waves. I know because the almost square wave (seen on an oscilloscope) that the PowerCom King Pro 800VA and 1000VA units put out are perfectly acceptable for a dozen or so machines here at work. All of which have PFC power supplies.
 
Last edited:
I did however get a few pure sine wave models for medical equipment we have. And for my servers we have APC and Cyber Power units from 1500VA to 2200VA. I am not sure if any of these are pure sine wave.
 
You must log in or register to reply here.
Back
Top