Yes, the ridged side is definitely much more damaged along most of its length than the smooth side, although there is some melting evident on the smooth side as well.
The whole cord is so melted and damaged that nothing is obvious. It is melted all the way through in a couple of places.
I’d be interested in actually running some tests on this cord. If you feel like sending it to me, email me. I’m pretty sure you can forgo the postal insurance. 
posted by QED,
" If you got a transformer question, I’m the guy to ask. "
Yep, and I did. I noticed you DWC, and Cornflakes in this thread, all posters who’s opinions I regard highly.
Colibri Post,
"Yes, the ridged side is definitely much more damaged "
Guys, the wire was damaged down the neutral, which means what?
I can only wonder at the possibility of a power surge from the aforementioned unreliable power plants. Anyone who live near you report any similar goings on?
If only one conductor showed signs of overheating, I would expect it to be the hot conductor, not the neutral. It would also mean that the over-current situation was caused by a ground fault.
If the entire length of the extension cord was cooked, then it obviously means there was too much current on the wire. A short (or near short) must have occurred somewhere close to the load. Here are the possibilities:
- Short inside the receptacle at the end of the extension cord.
- Short in one of the appliances (though I would expect the appliance cord to also be damaged).
- Short between hot (at the receptacle) and earth ground.
- A hot wire in an appliance shorted to earth ground.
It is interesting the breaker didn’t blow. Why is that? Q.E.D. offered one theory: Assuming there’s a 20 amp breaker, there was enough resistance in the short + extension cord that it “only” pulled somewhere between 16 and 20 amps. Or it could have been higher than 20 amps… at 25 amps (for example), a 20 amp breaker will not immediately trip. It will usually take a few minutes. Or the breaker is bad or frozen up, which is a very good possibility.
Any chance you have mice or rats? I have seen rats eat (and cause shorts) in cars many times. Does the damage start from one point and work it way back to the wall plug? If so look at where the damage starts for little tiny teeth marks.
Please post your findings, Q.E.D. or at least send me an email regarding what you’ve found-digital pictures, too. I’ll share with IAEI and fire service associates. Thanks.
Is it possible that the cleaning lady had something else plugged in to the extension cord at the time? It seems pretty coincidental for the cord to have melted during the .5% of the time that the cleaning lady is there, otherwise.
No, I’ve never had any. I’m sure that’s not the problem.
Of course, we could have a reversed hot and neutral situation here. They may have somewhat looser wiring standards in Panama than here in the US.
The only thing she could have plugged in there would have been the vacuum cleaner, but that’s not functional at the moment. (I didn’t have a replacement for the full dust bag). She says she was cleaning the bathroom, so I don’t think she would even have had the fan on.
This wouldn’t surprise me in the least. Building construction here is often pretty shoddy in general, and my building is no exception.
Sure, if Colibri feels like sending it, I’ll be happy to let you know what I find.
FWIW Crafter_Man, a linear load would equally heat both conductors, hot and neutral. Personally, I look at both conductors with equal suspicion, and may give additional attention to the neutral, given articles about 3rd, 6th, and 9th harmonics which I’ve read, although I doubt their applicability in Colibri’s situation.
Could a faulty breaker be to blame? Certainly. Federal-Pacific Stab-Lok, Zinnsco, and others are known for delayed-trip problems. That said, there still needs to be a load on the circuit exceeding the cord ampacity for the damage described to take place, and I don’t see it.
Only with the “coding” on the wire (smooth vs. lines, color coding, etc.) No matter how good or screwed up the wiring is, the fact remains that, if only one wire was cooked, it was very likely the hot conductor.
Assuming the over-current situation was not due to a ground fault, any load would equally heat both conductors (assuming the hot & neutral wires had the same resistance per ft).
Even a “good” breaker could be to blame. I seem to recall a thread a while back where it was recommended you manually cycle each breaker once per year. This keeps them from freezing up.
That was my point, was it not? Of course, if a manufacturing error resulted in a batch of power cord being produced with one wire being a significantly smaller gauge than the other, that could also account for the disparity, as well as the apparent lack of excessive loading causing the problem.
But he has two AC adapters on there. If they’re the “wall wart” kind, a short in the adapter could overheat the extension cord without affecting the wire from the adapter to the phone.
When you plug the AC adapters directly into the wall, does either one get really hot?
True enough. But then, I’d expect to see some blistering of the case.