Today we were dispatched for a wires down call. First arriving units observed a primary electric wire coming from an insulator on the apex of the electric pole into a nearby street side pear tree. The pear tree has strings of holiday lights in it which are wired into about 2 dozen more trees with lights in the block. A second wire which was broken from the grid at both ends was dangling from another tree about 50 feet down the street. We always consider the wire energized which was confirmed Atlantic City Electric on their arrival. If energized, the primary line voltage in our area is 7,200 volts.
AFTER the primary power was cut and rendered safe by Atlantic City Electric, we approached and found the wire had contacted the concrete and vaporized the sidewalk. In the picture, small black balls are visible around the hole. We suspect these are molten concrete which were melted by the energy and cooled as glass. The hole is larger in diameter that the quarter (placed for reference) and is at least 6 inches deep. Additionally, a section of concrete has “spalled”. This is the part of the sidewalk in the photo that looks like a golf divot. The concrete around the hole was superheated causing some water molecules trapped in the concrete to expand with enough energy to pop of sections of sidewalk. The wire pictured is the actual wire end that contacted the concrete. Please note the wire is 0.25" diameter solid copper with NO INSULATION. It’s just bare metal.
This is why we tell everyone to stay away from downed wires.
ADDITIONAL THOUGHT: Could the wire have energized the holiday lights in the tree? In every tree on the circuit? ***Please note, this photo was taken AFTER the electric utility made all repairs and gave the section of broken wire to the FD as a training tool.
