Depending on the model of UPS, you may be able to glean a lot of information from it. For starters, higher end UPS will augment line current with the battery- if it's getting 12A of 112V and it's set for 115V, it will use the battery to bring it up to 115V. Some cheaper UPS (the one on my home entertainment center, grrr...) will also sense an undervoltage, but switch entirely to battery. Considering this is a server drawing 12A, I'd imagine they have a high quality UPS. You're probably not lucky enough to have one of the REALLY good ones with interactive LCD panels with menus and data logging, though, huh?
Most common commercial-quality UPS have monitoring systems including an integrated voltmeter and clamp ammeter- APC Smart UPS will have a green bar graph right on the front showing system load, and red lights showing the status (undervoltage, overvoltage, overload, etc). Thus, you can pretty easily tell if the server is spiking to 18A (they can and do draw more current under load) or if it's coming from elsewhere. If you talk to the ITs, they might even have it hooked up to log the data and can give you detailed readouts of everything that UPS has seen.
Last edited by SteveFehr; 01/03/08 08:17 AM.
