Offshore earthing a different perspective

The various methods and philosophies available for grounding electrical power systems are diverse and offer the designer a plethora of choice. As a topic, not only is earthing arguably the most openly debated amongst engineers, but is possibly the least understood of all the electrical engineering subjects. Nowhere has this been more evident than in the offshore field, where the proliferation of earth bonding, particularly on equipment securely connected to substantial steel structures, has been far in excess of conventional onshore industrial practice. Against this background, the paper attempts to offer a practical insight on the characteristics of offshore installations, outlining the influence exerted by the steel structure on the impedance and return path taken by power frequency earth fault current