I had a service call last week to look at a outlet that had burned up. I am trying to surmise what happened to cause the small fire. Let me tell you what happened and you can tell me what really happened.

The outlet had a 6 outlet cover plugged into it*(without the hold down screw). The fire was actually between the outlet and the adaptor. No question where the fire happened. Big burn hole in the outlet and big burn hole in the adapter. This is obviously the weak spot in the system. The fire didn't happen until a delivery truck pulled down the service drop outside and then the outlet caught fire.

My question is how did the delivery truck cause the fire. Did it cause a low voltage-high current that the weak spot in the line could not handle?

BTW, they had more of the 6 outlet adapters plugged in over the outlet covers with no screws. More fires waiting to happen. They are fixed now.

I suspect this was nothing more than a cheap receptacle, overloaded by the 6 banger and what they had plugged in.

U/L does not say the device will not burn up, only that the fire will be contained.

what likely happen is a typical 15 amp receptacle is rated for only 15 amps for upto 3 hours of continious load. After 3 hours, that are rated only at 80% wich is 12 amps. With the number of plugs im a spliter, it is easy to put on 12-15 amp load on one. If the recept is on a 20 circuit, you can run up to 20 amps through a 12 (15)amp receptacle and not trip the breaker.

This is why cheap recepts melt after an extended time with a portable space heater. A 1500 watt heater draws 12.5 amps. a 12(15)amp will not carry it for long

My wife had an old 5-15 burn up with nothing but a vacuum on it. The cap was loose in the receptacle but she kept going anyway. I ended up replacing the cord and the receptacle. Both were toast.

Maybe when the service drop was pulled down, neutral broke first?

At a place I worked at many years ago, which has many critical computers all over the place, the night cleaning crew used company vacuum cleaners which has twist-lock plugs on them. A few strategically placed outlets were twist-lock type. This was to prevent them from using outlets on circuits with computers. It could also prevent them from operating with plugs half-way pulled out due to pulling the cord as far as it would go.

Is it a split wired receptacle?

I have a customer that has a mobile home with Aluminum wiring and when the flat screen and microwave and fish tank and dvd player are working it "trips" the circuit. When I come once a month he pays $150 for the service charge but won't pay to "fix it".

What do you do? Just reset the breaker? Maybe he should just move the microwave.

I keep informing him that he should rewire the mobile home or @ least add a circuit to the 60 amp "Main Range & floor. Apprantly, moneys tight.

This sounds exactly like one of those situations we were all lead to believe would be prevented by using the CAFCI’s, but as we now know, it most likely would not have helped. I’ll bet your inspector will still want one installed though, since the circuit has been altered by repair.