Thanks, Musicmaker! How can I fail to respond to an intro like that?
I had been hoping this thread would eventually fade out, as in hind sight, I probably shouldn't have posted a project with the inherent risks of messing with line AC...
I finally did some digging in the archives to find the original pictures since the ISP links died. Here is a re-post with the original context.
"The main unit is in the basement, with only an outlet box in the cabinet."
"This outlet has a cord that plugs into the main GFI, and routes power through 2 legs of 4 conductor wire down to the UPS. Either house current is sent back up, or it is switched over to inverter power."
"Here's a top view of the backup"
"The heart of the system is a transfer switch that consists of a relay normally energized with house power, and when that is absent, it turns on the 300w AC power inverter, and sends that power back up to the outlet."
"There are a few other bells in there, like a test switch, audible alarm, and indicator lights."