Bonding jumper

[1] "Bonding" is a method by which all electrically conductive materials and metallic surfaces of equipment and structures, not normally intended to be energized, are effectively connected with a low impedance path to avoid any appreciable potential difference between any separate points.

The common way to effectively bond different metallic surfaces of enclosures, electrical equipment, pipes, tubes or structures together is with a copper conductor, rated lugs and appropriate bolts, fasteners or screws.

Typically, these require a jumper at any place where the continuity of a bonding system might be interrupted, for example, where metallic conduits join an enclosure through fittings that do not assure good electrical contact.

[2] Some codes require a bonding jumper to be pulled into non-metallic conduit or in electrical metallic tubing that may be exposed to corrosion or mechanical damage.

Temporary bonding jumpers are used in the handling of flammable liquids and gases, so that static charge on a vehicle or portable tank does not ignite escaping gas.