Hey all,
Building out my lab, I was going to get a rackmount UPS. The one I'm looking at is a Cyberpower OR1500LCDRM1U. It says it offers:
1500 VA, 900 W, 120 V
Do I understand correctly that all I need to do is find the Wattage rating for each of the components I want to plug in and add them up? My components right now are pretty light, only about 120 watts total. But soon I'm going to expand and build out a Nutanix CE cluster with 3 nodes and a rack of drives. I was looking at using some NUCs but they are each rated at 330W.
So that would mean even the NUCs by themselves would over-provision the UPS right? Then on top of that I would still need all the other equipment in the rack to be powered.
Am I understanding this correctly or is there something I'm missing?
After you know the wattage of your load, use the Runtime tab on the product page to see how much runtime you get at a given wattage. https://www.cyberpowersystems.com/product/ups/smart-app-lcd/or1500lcdrm1u/
The one you have selected will have 2 minutes of runtime ~900w on a fresh battery. If all you want to do is clean shutdown, that's probably fine (as long as you don't have brief power drops that you want your shutdown procedure to ignore). If you need more time then you'll need a different UPS.
Note that some UPS models will do better for a given task than others with similar specs. For example I have a ~100w homelab, and wanted maximum runtime for 50w during a power outage (servers off, router+switch+aps active). Some similar spec Cyberpower models were ~120 minute runtime at 50w while others were 200+ for the same load.
Yeah so that's kinda what I was getting at. If I put in three NUCs that pull 330 watts, that's 990 watts to the NUCs by itself. If the UPS can only provide 900 watts, then pulling more than that just wouldn't work right? The UPS would essentially discharge in seconds right?
Correct. And as AtariDump points out, it's best to check typical runtime wattage, not peak, and not just on specs.
Are they 330 watts at idle or full load?
Will you be running them at full load 24x7x365?
Assume you are, if the NUCs take a total of 990w and the UPS is rated for a total of 900w, you’ll have negative runtime.
A server that isn't running at 100% has missed the meaning of it's life.
/s
You ain’t wrong