The shiny stuff is the slick outer covering of the wires burning --- v e r y s l o w l y ! ! in a M a r r i o t H o t e l in M e x i c o C i t y!!

what happened? overload or loose connection?

My guess is improper torque at installation.

"The end of the road, there aint more threads"? Was the wire too small for the connector, did the "electrician" tighten the connector untill it stopped, leaving the wire somewhat looses in the connector?

They squeezed the wires so tight that it caused an electrical bottleneck.

How come all three lugs are not the same color? Shouldn't they all be black? Mine are always black... after awhile . He probably did not cut off enough strands on C phase.

Pierre

PC .... That's it, I wasn't sure about that phase! Thanks for solving the puzzle! I always thought they were "polishing" the lug to sort of keep them clean.