TR Forums

I recently bought a server and want to add two UPS to it. it has a dual power supply rated at 550Watts (230/115V). If I have a separate UPS on both connections and have a power outage, will it drain UPSs at the same rate, or will the load be less because there are two of them?

This will depend on how the system is configured. All my dual power supply systems are set to share the load across both power supplies, in which case it draws half the power from each supply. So, if it is using 250W, it will draw 125W from each power supply, and hence from each of your UPSes.

There is no real need for a UPS on both power supplies, or to plug the power supplies into separate UPSes. That will come down to how much you are chasing reliability.

--SS

The UPS I was looking at, according the the manufacturers web site, gave me an estimated time of 19 minutes to run the server if there is a power outage. We quite often loose power for 15 to 30 minutes. I was thinking if I put the separate power supplies on two different UPSs that I could push the up time to 38 minutes. Is that reasonable?

Probably, yes. You need to ensure the server is sharing load across both power supplies. It would be unusual for that not to be the case, but worth checking. If its an enterprise class server that has an web interface for its BMC, you should be able to find it under there somewhere.

--SS