This not festive UPS unit did not trigger any alert (the network card and other monitoring systems were configured and working correctly) other than a electrical burning smell.
The rack of equipment this UPS protects was shutdown in an orderly manner and moved to other power until the replacement UPS was installed a week later. Running the same equipment on house power was minimal risk except for the server's need for sustained power in the event of a power loss.
The not festive UPS itself was disconnected from the main power feed and fully shut down. By this time, a smokey haze was filling the small IT room. A basic visual inspection with the face plate removed did not show any obvious damage. The main battery connection was disconnected at this time. The local office's vendor shipped the replacement unit (existing unit was out of...