Apparatus to monitor electrical cables, including splice joints and the like, for the ingress of moisture

摘要

Apparatus for monitoring electrical cables for the presence of moisture within the cable along the full length of the cable and at specific points such as splices along its length comprises a pair of dielectrically separated conductors arranged along the length of the cable for communicating between a central station and remote stations along the length of the cable at the specific points to be monitored. The remote stations each include a further dielectrically separated pair of conductors for sensing moisture at the point and signals along the first pair of conductors to the central station. The central station detects moisture by an increase in current in the conductors and also detects a signal from remote stations. Branch cables spliced into the main cable include dielectrically separated conductors also spliced into the main conductors with the remote station at the splice including means for disconnecting the branch cable conductors from the main cable conductor under control from a signal from the central station.