Bad outlet in garage?

[Lbisurfcaster]

Hello Everyone.. This is my first post to the board, and I have to say I enjoy reading and learning from all the experiences( bad & good) that all of you have shared! I know there is no stupid quesiton especially when it comes to electrical, so here it goes. I was inspecting a 41yr old split level house with a newer 200amp service. I had not inspected the panel just yet, but as I was testing one of the 10 outlets in the garage(8 grounded, 1 GFI, 1 Open ground) the outlet next to the GFI sparked like the 4th of july melted the two prong on my tester and tripped the breaker. This was the first time this had ever happened with over 450 inspectons under my belt. What could have caused this to happen? I should have mentioned this was a general contractors home..!

Any help would be greatly appreciated.

[Jeffrey R. Pope]

So many possibilities, so little time

Was the box and/or cover metallic? Were you able to determine if it was wired properly prior to its meltdown?

I report conditions such as this as Failed under normal testing/operation.

[Jay Moge]

i've seen this happen once. and being the curious type i investigated after replacing the outlet. well ya know how there are two tabs for both the hot and neutral inside the outlet? well the to on the inner part of the plug had let go, and shorted out onto the screw that held the cover plate on, and caboom. even melted the prongs to the plug the tenent used. oh and the complex is 40 yrs old and this duplex looked original.

[Lbisurfcaster]

Thanks Jeff and Jay.. I think we have had similar experiences Jay. After pulling my tester from the outlet at the speed of light, Un-able to determine if it was wired correctly due to firework display, the metal cover plate fell off and I heard the screw hit the floor. Could it have been the plate was already loose? or when the short occured did it shear the screw off causing the cover to plate to come with it?

Thanks for the quick response guys..

Chris