Sheath current

A sheath current is a form of charge transfer in wires. Sheath currents can run along the outer sheath of a coaxial cable. This can be caused by a geographically proximate or remote ground potential.

Sheath currents may lower the efficiency of transmission and can interfere with nearby electronic devices. In addition, sheath currents caused by differences in ground potential at the ends of a coaxial cable to common mode signals that are superimposed on the useful signal as a noise voltage. Sheath currents can be caused by ground loops.