Need help understanding current power usage in our server room

[NathanBWF]

I need help understanding how much power we're currently using in our server room, and how much more I can use before we start running into power problems. Here is a current screen shot from our APC UPS unit:

Pic

We have an IBM Blade Center with 7 HS20 blade servers, and Fiber Channel SAN, and about 10 other tower/rack mount servers currently running. We're going to be adding more servers in the near future, as well as an expansion drawer to our SAN.

Basically, I want to know how many more things we can add to this server room before we start flipping breakers. I'm not a power engineer or an electrician thus don't fully understand what my UPS is telling me.

Can anyone provide me with any input based on the screen shot above?

 

[sieistganzfett]

your best off putting this under the networking section, i doubt anyone in this forum anyone would even answer it since no one would have any idea what to say. thats one mighty nice UPS. about 10-15k dollars, weighs a ton. APC has the best technical support, i'd call them and ask them what each means. i thought your connecting into 230V, but it says ~204V i'm confused on that actually.
http://www.powerstream.com/VA-Watts.htm will explain some of it for you.

 

[PowerEngineer]

Well, I'm guessing you have this UPS set up for its maximum configurable output of 12 kva and 8.4 kW. There's a lot of information available on the site.

The good news is that you're currently showing a load of 2.82 kva -- less than a quarter of its kva rating. Interestingly, it doesn't show how much of that is real power. If you make the conservative assumption that it is all real power, then you're still just over one third of the 8.4 kw rating.

You might want to first verify that 3 kva is indeed the maximum load for your current equipment (i.e. make sure everything is turned on). The next step is to ask the equipment vendors for power consumption specs to see how much load you need to add.

I'm thinking that you could probably double your current loading without too much risk. You should certainly talk to APS or your maintenance contractor before making any final decisions.

Some other things to consider:

The amount of load on a UPS has a direct (and obvious) effect on the length of time it can serve your loads once outside power is lost. Doubling the load will halve the time. So think about battery capacity too.

One way that you can enhance UPS reliability is to buy units with higher capacities than you really need. The theory is that this puts much less stress on their components and increases their mean time between failures (not sure if this as valid for newer technologies). This may be the reason that your UPS is so large in the first place.

I'd also check into possible cooling issues. The UPS might dissipate more heat at higher loadings, so you want to be sure your HVAC is up to it.

Good luck!

 

[NathanBWF]

Originally posted by: sieistganzfett
your best off putting this under the networking section, i doubt anyone in this forum anyone would even answer it since no one would have any idea what to say. thats one mighty nice UPS. about 10-15k dollars, weighs a ton. APC has the best technical support, i'd call them and ask them what each means. i thought your connecting into 230V, but it says ~204V i'm confused on that actually.
http://www.powerstream.com/VA-Watts.htm will explain some of it for you.

Thanks for the reply. Yes, it is a nice UPS...we spent a lot of money on it but it was worth it.

And yes, APC Tech Support is tremendous. I'd rank them right up there with IBM.

 

[NathanBWF]

Originally posted by: PowerEngineer

Well, I'm guessing you have this UPS set up for its maximum configurable output of 12 kva and 8.4 kW. There's a lot of information available on the site.

The good news is that you're currently showing a load of 2.82 kva -- less than a quarter of its kva rating. Interestingly, it doesn't show how much of that is real power. If you make the conservative assumption that it is all real power, then you're still just over one third of the 8.4 kw rating.

You might want to first verify that 3 kva is indeed the maximum load for your current equipment (i.e. make sure everything is turned on). The next step is to ask the equipment vendors for power consumption specs to see how much load you need to add.

I'm thinking that you could probably double your current loading without too much risk. You should certainly talk to APS or your maintenance contractor before making any final decisions.

Some other things to consider:

The amount of load on a UPS has a direct (and obvious) effect on the length of time it can serve your loads once outside power is lost. Doubling the load will halve the time. So think about battery capacity too.

One way that you can enhance UPS reliability is to buy units with higher capacities than you really need. The theory is that this puts much less stress on their components and increases their mean time between failures (not sure if this as valid for newer technologies). This may be the reason that your UPS is so large in the first place.

I'd also check into possible cooling issues. The UPS might dissipate more heat at higher loadings, so you want to be sure your HVAC is up to it.

Good luck!

Thanks for the very informative post! :beer:

You've definitely provided me with some valuable info, and pointed me in the right direction...