I will soon get photos in here, but what happened is still a bit of a mystery. I noticed one light was not working. Started checking and found no power there. Checked entrance box and a 25 amp breaker had tripped. It would not reset. Tracked the circuit and found that a heavy-duty extension cord plugged into the six-outlet extension showed melted plastic on each end. The end at the outlet was white plastic charred black.
The heater plugged in worked in another outlet as it should. Other loads were negligible. The cord plugged into the six-outlet strip had a male terminal literally welded to the brasss connector in the extension strip. We were very lucky to not have had a fire.
I don't know anything for sure, but I suspect it might make sense to pull plugs out of any extension cord or strip now and then and replug them to possibly break up oxidation or corrosion. So far my best guess is that such a bad connection started arcing which produced the heat without using enough current to trip the breaker on the extension strip. Then the hot side contracted the ground or the other side of the connector and finally tripped the 25 amp circuit breaker at the entrance box.
Anybody with other ideas or similar experience, let me know. I suspect many of these things are on carpets and behind sofas and other furniture where any kind of arcing or over-heating could start a serious fire. Mine was up on a wall with no carpet in the area.
Did a Google search. Found a similar situation Danger, Fire Ahead.
And pretty colors may hide electric fire danger too And some useful info (and hype) on Power Strips and fire danger. And from Emory University-- Toolbox Safety . About 50 questions and answers on surge protectors here-- Surge and Strip FAQs. And scroll down and down at a North Caroline Law Firm Warning of Fire Danger (and law suit potential?). And from "Consumer Affairs" (not to be confused with Office Affairs) you can find 27 complaints from people with all kinds of electrical problems.
That is enough of that. On Monday, I will contact the South Dakota Fire Marshall office and see if they have found examples of power strip failure producing fire. Many colleges and universities have info on use and abuse of these strips.
[[[ Note: I did get in touch with SD Fire Marshall Office and they called back after looking at image here. Found out it is a bad idea to plug extension cords into them. I still don't get the physics of that problem however. Also that one of the things they inspect for in SD Schools is the use and abuse of those power strips. I may get more info from the SD Fire Marshall and if I do, will post it here or provide a link to the information.. I did look at the packaging for a number of multiple outlets. Most have no reference to dangers of extension cords. Others give conflictiing information in the fine print that says in one sentence "Don't use two-wire extension cords or adapters". Then a few lines later indicates no kind of extension cords should be used. Other have no warnings of any kind. After talking to the fire marshall office, I think is is wise not to plug any single appliance into those strips which by itelf uses power close to the maximum rating.. I still don't know for sure what happened to this one, but my limited experience suggests these things deserve a bit more attention despite the package big print which usuially indicates the breaker in them makes them safe to use. More to come on this I am sure.--- Doug Wiken ]]]
This morning (March 19, 2013, I got more information from Doug Hinkle at the SD Fire Marshall Office. It is posted on one of my Notebook Pages--- Fire Code Info. Check it for more information. This may all be much ado about not much, but the charred and melted plastic and the "welded" connectors certainly caught my attention.
*** Stay tuned even if all your connections are political-- Doug Wiken