Electric Utility Glossary - Section J
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Johnny Ball – A porcelain (or other insulating material) device used in series with guy wire to electrical isolate the wire near the ground from wire near an energized conductor. The most common size is the about the size of a coffee cup.
Joule – One joule is the energy required to move 2 kilograms at a speed of 1 meter per second, or in the English system, the energy required to move 0.91 pounds at a speed of 3.3 feet per second. It is equal to 2.778 x 10 -4 Watt-hours. It is named after James Joule (1818-1889) who demonstrated the relationship between thermal and mechanical energy.
Jumper – A jumper is a relatively short piece of wire used as a conductor. This includes the wires that connect a pole mounted transformer to the energized conductors. It is also used to describe the wires than connect capacitors to the energized conductors. Jumpers are also used to connect the two terminals of a capacitor for shipping and storage.
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