New addition to UPS, now full load

[fizzak]

I need to sacrifice something. I have 3 servers on a SmartUPS 1000. I have the redundant supplies form these servers on it as well. If I take the redundant PSU's off of it, will it save me some load?

 

[cajuntank]

Of course. Every power supply draws power and depending on the wattage of the power supplies themselves, probably exceeds or comes right up to 1000va.

Since you don't mention what server you have, let's use the example of an HP Proliant DL360 G5 server. The power supply that comes with it maxes at 850va at 110V. So with that one power supply, your at about 65% of utilization already. One thing that some people don't take into consideration either is amperage. Your 110V wall outlet is probably rated at 20Amps. Each power supply in my example above uses between 7-8Amps at 110V. So on one dedicated circuit, even if you have enough volt-amps to handle the volt amp needs of the power supply/supplies, you would only have enough amperage to cover 2 and some change, again, based on my example above. Of course all of the above changes some if you move from low voltage to high voltage.

Hope that helps.

 

[fizzak]

Ok lets say I have a DL380 with both supplies attached to the UPS. Is it feasable to run one supply off outlet power and one off of the UPS? I know this will reduce the load and I know this will still run the DL380 if power is down.

 

[cajuntank]

Of course... I would still have that non-UPS connection into at least a surge protector, but I do the very same thing with my servers in some situations where I cannot have redundant UPS's, circuits, etc...