Smart-UPS 1500 doesn't engage during power failure

[Anonymous user]

We have a Smart-UPS 1500 that fails to keep our server running when even te smallest power failure occurs. As I understand it, this has been the case since it was new in 2007. I am inheriting this problem and decided to see if the unit is worth saving. The battery was replaced in November of 2012 and appears to be working properly. PowerChute reports that the battery is fully charged and that we are only at 22% of the max load, but the server shuts down/restarts any time the power fails - even if it's a blip. Does anyone have any suggestions?

[BillP]

Hello - Is this server the only load powered by the UPS? I would see if the same behavior happens with more than one piece if equipment. And also try it with a piece of non critical load making sure the USB or serial cable is removed to make sure that is not contributing to the behavior. 

Lastly, the UPS remains on when it switches to battery, correct? It is only the server that sometimes reboots or sometimes turns off? 

[Anonymous user]

The UPS only has the server, its monitor and an ioSafe external hard drive plugged into it. I understand that the behavior occurred before the ioSafe was added. I pulled the UPS from the server and moved it to a Mac workstation and tested it by cutting the power from the breaker and it works as expected. I think the Mac Pro uses a similar amount of power to the Dell PowerEdge 1900 server (the Load indicator on the front of the UPS has one of the five lights lit, just like when it's on the server). The Smart-UPS 1500 is what Dell suggested when we bought the server. Could it be the server that is the problem? It only does this during a power failure/blip. If the UPS is providing uninterrupted power, this shouldn't occur.

[BillP · Accepted solution]

It very well could be a faulty power supply or some type of incompatibility with the power supply type (which with a Smart-UPS is rare) but could happen if the power supply is sensitive to the transfer time to from battery. Anyway, that is why I suggested to see if everything plugged into the UPS exhibits the behavior or if it is narrowed down to just the server.

So if you do this same manual test of tripping the breaker with the server, it does do it as well as real power blips? Or are you saying only during blips (versus simulating a blackout with the breaker) it does it with the original server?