Grid Earthing System

The earthing system in a plant / facility is very important for a few reasons, all of which are related to either the protection of people and equipment and/or the optimal operation of the electrical system. These include:

• Equipotential bonding of conductive objects (e.g. metallic equipment, buildings, piping etc) to the earthing system prevent the presence of dangerous voltages between objects (and earth).
• The earthing system provides a low resistance return path for earth faults within the plant, which protects both personnel and equipment
• For earth faults with return paths to offsite generation sources, a low resistance earthing grid relative to remote earth prevents dangerous ground potential rises (touch and step potentials)
• The earthing system provides a low resistance path (relative to remote earth) for voltage transients such as lightning and surges / over voltages