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.

An adapter probe configured for injecting fluid (e.g., liquid, gas) into at least one electrical cable. Particularly for injecting an electrical cable with a fluid when the electrical cable is affixed to a separable connector (e.g., elbow separable connector). Separable connector may be configured to connect sources of energy (e.g., transformer, circuit breaker) with distribution systems via electrical cable (or cable section).

A method for repairing a damaged area of an outer jacket layer of a cable or cable accessory includes: applying sealant to a strip of flexible material; forming a preliminary sealant layer on the damaged area and around an entire circumference of the outer jacket layer by sliding the strip of flexible material relative to the outer jacket layer with the sealant in contact with the outer jacket layer; wrapping the strip of flexible material around the entire circumference of the outer jacket layer and the preliminary sealant layer, wherein the preliminary sealant layer holds the strip of flexible material in place after the wrapping; and allowing the sealant to cure to thereby form a final sealant layer on the damaged area and around the entire circumference of the outer jacket layer, wherein the strip of flexible material holds the sealant in place while allowing the sealant to cure.

A method for repairing a damaged area of an outer jacket layer of a cable or cable accessory includes: applying sealant to a strip of flexible material; forming a preliminary sealant layer on the damaged area and around an entire circumference of the outer jacket layer by sliding the strip of flexible material relative to the outer jacket layer with the sealant in contact with the outer jacket layer; wrapping the strip of flexible material around the entire circumference of the outer jacket layer and the preliminary sealant layer, wherein the preliminary sealant layer holds the strip of flexible material in place after the wrapping; and allowing the sealant to cure to thereby form a final sealant layer on the damaged area and around the entire circumference of the outer jacket layer, wherein the strip of flexible material holds the sealant in place while allowing the sealant to cure.

A method for rejuvenating a strand-blocked cable having a conductor comprised of a plurality of conductor strands with interstitial volume therebetween blocked by a PIB based mastic, the conductor being surrounded by a polymeric cable insulation. The method comprising installing injection adapters that seal the cable ends of the cable and are usable to inject fluid into the interstitial volume between the conductor strands of the cable; elastically expanding the polymeric cable insulation through the application of pressure to the interstitial volume between the conductor strands of the cable; and injecting at least one injection fluid in which the PIB based mastic is at least partially soluble into the interstitial volume between the conductor strands of the cable. To facilitate elastic deformation of the polymeric cable insulation, the cable may be heated to and maintained at a temperature of T1 above ambient during the injection.

Provided are methods for extending the life of in-service electrical cable having polymeric insulation, comprising injecting into the cable a dielectric gel formulation containing: (a) SiH endblocked polydiorganosiloxane (H(R.sub.2SiO).sub.x(R.sub.2Si)H); (b) polydiorganosiloxane endblocked with unsaturated carbon-carbon functionality; (c) hydrosilylation catalyst suitable to cure (a) and (b); and (d) at least one organoalkoxysilane functional additive (e.g., anti-oxidant-based alkoxysilane, voltage stabilizer-based alkoxysilane, hindered amine light stabilizer (HALS)-based alkoxylsilane, UV absorber-based alkoxysilane, etc.), wherein (a) and (b) are cured post-injection into a non-flowable gel, and wherein (d) diffuses into the insulation. The methods may further comprise a hydrolysis/condensation catalyst compatible with the hydrosilylation catalyst so as not to interfere with the cure of (a), (b) and (c), and/or be compatible with optional siloxane crosslinkers, and/or with optional hydrosilylation inhibitors.

Provided are methods for extending the life of in-service electrical cable having polymeric insulation, comprising injecting a dielectric enhancement fluid composition into the cable, wherein the composition comprises: (a) one or more organoalkoxysilane functional additives (voltage stabilizer-based, hindered amine light stabilizer (HALS)-based, and/or UV absorber-based); and (b) a catalyst suitable to catalyze hydrolysis and condensation of (a), the injected composition providing for rapid initial permeation of (a) into the insulation, and extended retention of subsequent condensation products of (a) in the insulation. Additionally provided are innovative silyl functional ferrocenes (e.g., containing a ferrocene moiety and a silyl function hydrolysable to silanol) having utility as functional voltage stabilizing additives in the methods.

A method in the manufacturing of an insulated electric high voltage DC termination or joint includes providing an insulated electric high voltage DC cable including a high voltage DC conductor, a polymer based insulation system surrounding the high voltage DC conductor, the polymer based insulation system including an insulation layer and a semiconducting layer surrounding the insulation layer, and a grounding layer surrounding the semiconducting layer; removing the grounding layer and the semiconducting layer in at least one end portion of the high voltage DC cable, mounting a field grading adapter or joint body in the at least one end portion of the high voltage DC cable; and subjecting the insulation layer of the polymer based insulation system in the at least one end portion of the high voltage DC cable for a heat treatment procedure, while being covered by the mounted field grading adapter or joint body.

A method in the manufacturing of an insulated electric high voltage DC termination or joint includes providing an insulated electric high voltage DC cable including a high voltage DC conductor, a polymer based insulation system surrounding the high voltage DC conductor, the polymer based insulation system including an insulation layer and a semiconducting layer surrounding the insulation layer, and a grounding layer surrounding the semiconducting layer; removing the grounding layer and the semiconducting layer in at least one end portion of the high voltage DC cable, mounting a field grading adapter or joint body in the at least one end portion of the high voltage DC cable; and subjecting the insulation layer of the polymer based insulation system in the at least one end portion of the high voltage DC cable for a heat treatment procedure, while being covered by the mounted field grading adapter or joint body.

A cable accessory for injecting fluid into a cable. The accessory has first and second ends configured to be coupled to the cable and an external cable accessory, respectively. The accessory has an injection port configured to introduce the fluid to a stranded conductor of the cable. The accessory may include a body and conductive rod. The body defines a through-channel configured to receive the conductor. The rod has a first portion that extends outwardly from the second end to be received inside the external cable accessory and to form an electrical connection therewith. The rod has a second portion configured to be coupled to the conductor and form an electrical connection therewith. The second portion (with the conductor coupled thereto) is positionable inside the through-channel with the first portion extending outward from the second end. The fluid is injectable into the conductor through injection port, which extends into the through-channel.