Earthing of Buildings

Earthing is an important element of any lightning protection system and general building electrical protocol. It provides for safe discharge of the current from the strike to ground.

There are therefore strict guidelines to the installation and maintenance of these systems. There is an overlap between lightning protection earthing and general electrical earthing for structures and for their ancillary electrical MV and LV stations supporting them. In other words the lightning protection code of practice in Ireland's (ISEN 62305) lightning protection earthing guidelines overlap with the ETCI and BS 7671 in what is required.

Earth resistance is the measurement of the resistance of the soil to the conductivity or passage of an electrical current. On its own the components of soil tend to be poor conductors however with the installation of copper earth systems we are able to reduce this value to acceptable levels.

Rainey & Co provide the following services in this area to form a complete service of suites in this area:

Soil resistivity testing

This is an important element in the initial stages of planning an earthing system as it enables us to establish where the earth is of good quality for this and also helps give an idea of the extent of earthing that will be required given differing soil qualities.

Installation of earthing systems

Earthing systems are made up of earthing tapes / cables, bonds, rods, plates, earth mats which are made of copper 99% of the time. Whether of not this copper is insulated or not or if the bonds to the various parts are welds or mechanical bonds is down to the design under the code of practice. Soil enhancing compounds are also used to achieve good readings as required.

Earth resistance testing

Earth resistance testing is the process by which we commission and certify our earthing systems. This is also an important part of the testing of earthing systems which are required at regular intervals to ensure that the earth resistance remains at a safe level. The Wenner principle outlines the process of this test: A current and potential electrode are driven into the ground equidistantly apart and the earth under test isolated and tested directly using a currently calibrated specialised tester.

Rainey Co are unrivalled in Ireland in terms of our experience at providing earthing systems for lightning protection systems as well as for sub-stations, wind turbines and plant and machinery from all industrial sectors making it safe for use and purpose.