Abstract: Described is a cable rejuvenation apparatus for a cable used in a subsea environment. The apparatus applies a bias signal to a conducting element of the cable, the bias signal being selected to improve the insulation properties of the cable. The bias signal is generated by a bias signal generator that includes a voltage source that generates a bias voltage having a time varying component. The bias voltage promotes an electrochemical reaction between the conducting element and the salt containing liquid of the subsea environment resulting in the formation of a barrier material at the fault location restricting further leakage current flow and enhancing the insulation resistance of the cable. The bias signal is a voltage selected such that the electrochemical reaction promoted by the bias voltage maintains the presence of the barrier material at the fault location.

Abstract: Described is a cable rejuvenation apparatus for a cable used in a subsea environment. The apparatus applies a bias signal to a conducting element of the cable, the bias signal being selected to improve the insulation properties of the cable. The bias signal is generated by a bias signal generator. The bias signal can be a voltage which promotes an electrochemical reaction between the conducting element and the salt containing liquid of the subsea environment resulting in the formation of a barrier material at the fault location restricting further leakage current flow and enhancing the insulation resistance of the cable. The bias signal is selected such that the electrochemical reaction promoted by the bias signal maintains the presence of the barrier material at the fault location.

Abstract: Described is a rejuvenation method for a cable used in a subsea environment. The method includes applying a bias signal to a conducting element of the cable, the bias signal being selected to improve the insulation properties of the cable. The bias signal is selected such that, in the event of an electrical leakage current of predetermined magnitude flowing between the conducting element and a salt containing liquid of the subsea environment at a fault location. The bias signal can be a voltage which promotes an electrochemical reaction between the conducting element and the liquid resulting in the formation of a barrier material at the fault location restricting further leakage current flow and enhancing the insulation resistance of the cable. The bias signal is selected such that the electrochemical reaction promoted by the bias signal maintains the presence of the barrier material at the fault location.

Abstract: An apparatus includes a voltage source, voltage measurement means and a processing means, and connects to a line to apply and monitor a voltage between the line and earth. The processing means controls the voltage source to transmit and receive communications from the line, via the voltage measurement means. The apparatus also has a first and second current measurement means. The voltage source is connectable to a wire under test to inject a predetermined test voltage on the wire. The wire extends in a first and second direction from the test location. The first current measurement means measures the leakage current from the voltage source flowing along the wire in a first direction, and the second current measurement means determines the leakage current along the wire in a second direction, and the processing means uses the current flows measured by both current measurement means to determine wire insulation properties.