Training Day: Conductive Concrete Retrospective Install, Openreach

Case Study

As part of Openreach NGA (Next Generation Access) project being rolled out to enhance fibre networks across the UK, Cubis invited Openreach representatives along with a number of contractors to the Silverwood production site in Lurgan to present a live demo installation of SAN-EARTH conductive concrete for use in retrospective installations.

The installation which took place at the Lurgan production site was facilitated by Cubis, with the site excavation and cabinet provided by Openreach Contractors - KN Networks. Product training was carried out on-site to advise site operatives on the process for installing Cubis' long term grounding product Conductive Concrete in retrospective environments.

With the installation site prepared 4 no. Cubis San-Earth Conductive Concrete bags, 2 litres of Cubis San-Earth XLR8 and Cubis' RetroS cable assembly were placed at the side of the excavated area.

The grounding electrode was installed first by feeding the cable assembly under the Openreach cabinet through the excavated area and insulating the bare cable within the trench excavation with a cut section of duct 36. Having fed the electrode through the duct, this was then attached to a 1.5m section of specially cut duct to aid with insertion and placed loosely within the 1.2m deep earth pit.

2 no. San-Earth Conductive Concrete bags were then added to a mix of 20 litres of water and 1 litre of accelerator to form a concrete slurry. With one operative holding the electrode centrally within the earthpit with the aid of the pre-cut 1.5m section of duct, this mix was shoveled around the electrode.

This step was repeated for a second time with another blend of conductive concrete, accelerator and water placed around the electrode until the earth-pit was completely full. The duct was then detached from the electrode and pulled out of the pit, allowing the electrode to remain completely surrounded in conductive concrete.

The earth electrode was immediately tested for Ra and results documented, with the concrete left to cure same-day. For the purposes of demonstration a secondary earth pit was then excavated and fitted with an electrode using the same steps as above to denote the steps taken if the primary electrode reading was to measure over 130 Ohms.

Findings prevailed that the resistance to ground was substantially reduced and with that the surface area of the electrode dramatically increased. In addition, surge impedance was also lowered significantly.

As a proven solution in the prevention of infrastructural conductivity grounding difficulties, Cubis SAN-EARTH not only excels in terms of technical performance but is environmentally safe, reduces theft of copper earthing rods and enhances the installation process through safety, time and cost in the grounding of BT telecommunication cabinets.

For more information on Conductive Concrete visit www.conductive-concrete.com.