When taking apart faulty outlets I found melted white wire terminals. I'm told these are the first two outlets on the circuit. The first outlet seemed to melt from both white leads equally without breaking the connection. The second outlet seemed to melt only from one white lead, and got hot enough to melt the wire off the terminal and break the connection, killing the rest of the outlets down the line.
I would blame it on a loose connection or bad plug, but two mistakes right next to each other seems to me less probable. And why only the white leads, not the live wire? Happy to offer more details if they're helpful.
First outlet in the series, white leads (melted) and black leads (fine)
Second outlet in the series, white leads (one melted) and black leads (fine)
The outlets are about five feet apart, if that matters.
Best Answer
Looks like they got loose. If the connection is loose it will arc and create a lot of heat if something that draws a lot of current is plugged in.
It also looks like they got wet. There is rust and the copper wire has a patina. That would not help. If the outlets are below a water source that leaked, that could have contributed. Or maybe someone sprayed water into the outlets.
I guess they're making receptacles even more crappy these days, I'm used to brass screws which would never rust (and are more electrically conductive than mild steel). The old bakelite (thermoset) plastic receptacles also would not melt.
Incidentally, this is why connections are made in a fire-resistant box. There are also initiatives to incorporate mandatory arc detection into fuse panels. The arcing has a characteristic signature that can be used to shut down the circuit. Arcing still (rarely, fortunately) causes house fires, but it was worse when they were installing aluminum wire.