Where do high voltage arcs typically exist?

High voltage arcs typically exist at the transformer connection near the service entrance of a building due to several factors. The transformer plays a critical role in stepping down the high voltage from power lines to a lower voltage that can be used safely within homes and buildings. At this junction, there is often a significant potential for arcing caused by insufficient insulation, mechanical failure, or loose connections.

When electrical current encounters a break in continuity or an improper connection, it can jump through the air, creating an arc, which is characterized by its high temperature and light. The service entrance is particularly vulnerable because it is the first point of contact for electricity entering the building and often involves various connections and components that need to be securely maintained.

In contrast, other options lack the same conditions for high voltage arcing. Heating ducts and insulated wires in the attic typically do not operate under high voltage conditions conducive to arcing. Underground power lines, while they are under the ground, are generally designed to be insulated and protected from external elements, thereby reducing the likelihood of arcs occurring compared to exposed connections at the service entrance.