Stray Voltage: How it is created
At the most basic level, stray voltage (SV) is the product of a broken, poorly designed or poorly implemented power delivery system. In New York City, over 25,761 such failures were found over the last 6 years. These failures resulted in voltage being detected on more than 34,720 streetlights, manholes, sidewalks and other such objects.
Exposed wiring in underground power delivery lines is a common source of stray voltage in New York City. Underground cables are often housed within a metal container or conduit. When the insulation around the power lines deteriorates, exposed conductors can come into contact with the metal conduit, which can transmit the voltage to numerous public objects (street lights, sidewalk gratings, etc.). This is usually facilitated by water, which can accumulate in the conduit and provide a path between the exposed wires and the conduit walls and subsequently the street. Important to note, one such breakdown in the power delivery infrastructure can (and usually does) create multiple energized objects in the pedestrian pathway. To help prevent this typical type of failure, Con Edison has started a program to replace the single-jacket cable with dual-jacket cable, which provides more durability. Though a step in the right direction, at the current pace it will take approximately 31 years until all 70,000 miles of cable are upgraded.