B1.1.3 Cable accessories

Function

Cable accessories are used to provide electrical termination and mechanical support for cables both during and after installation.

What it costs*

About £36 million for a 1 GW wind farm.

Who supplies them

Interface plugs: Pfisterer, Ridderflex and TE Connectivity.

Hang-off clamps: BMP, Vos Prodect and WT Henley.

Cable connectors: Nexans and Pfisterer.

Cable terminations: Prisma Components 

Cable grips: Prisma Components

Key facts

Pulling heads enable the safe installation of the cable to the platform. It typically connects directly onto the cable armouring to ensure that all mechanical forces associated with pulling the cable via the J-tube are borne by the armour rather than the core. They are usually made from machined steel and hot dipped galvanised and zinc plated.

Kellums Grips are often used for lighter weight or lower tension installations

Hang-off clamps are installed where the cable connects to the turbine’s foundation or that of the substation. They ensure that the cable is mechanically secured after installation and that the mechanical stresses expected to occur during service life are safely borne by the cable armouring and not by the core.

Terminations boxes connect the cable conductors to the electrical switchgear above the hang-off assemblies. Terminations connect to inline or T-connectors at the switchgear. Interface plugs are typically fitted at the end of the cable to form the connection point between the cable and the termination box.

Coupling connectors installed in piggy-back assembly to a T-connector allow a second cable connection. Surge arresters could be also installed in piggy-back assembly to a T-connector. These are insulated using ethylene propylene diene monomer (EPDM).

J-tube seals are used to seal the interface between the inside of a J-Tube and the riser. Water containing a corrosion inhibitor is normally introduced into the J-tube void.

Cable protection systems (CPS) are often employed to ensure the cable is not subjected to excessive loadings through the cable route as the cable departs the foundation and continues onto the sea bed.