As we keep collecting more and more folding gear, please remember to look at any extension cords your using.. I've been adding gear to my garage rack and wasn't watching that I've overloaded my 10A 1250W extension cord. I had the circuit breaker popped during the day. I came home, gave it a quick look over and figured it was just bad luck and power it back up. About 2 hours later, I'm in the garage and the same circuit breaker blows again. This time one of the UPS won't come back up. I grab the cord to trace it back to the power support and it hot (Oh Boy!), so I went to unplug it and couldn't pull it out. It apparently melted together.

Uploaded with ImageShack.us
 
It all fun and games, until something catches fire!

Good thing you found that.
I only use 12 or 14 gauge wire extension cords.
12 gauge is good for up to 20 amps.
14 gauge wire is good for 15 amps.
Never run a coed under a rug or carpet either.

I never run anything long term on extension cords.  That's always been considered a fire hazard in the military.  I suppose that has done much to keep me safe here at home too.

So I've done a little research. The reel extension cord are not very good especially for sustain loads.

I should also note that the psu power cord come in different sizes and power ratings:

AWG 18 are maxed at 10 Amps
AWG 16 are maxed at 13 Amps
AWG 14 are maxed at 15 Amps

My AMD 4P rigs and my SLI 580 box normally are running at 7 Amps and I believe my 1500 Va UPS can push the whole 15 Amps. As you can see connecting two of these on the same extension cord can push beyond the limits. If you got a bunch of these laying around, it easy to, grab the wrong one and connect it up trying to get something working.

I buying some AWG 14 for my big 1500 UPS.