Lightning protection is the process of directing strikes to ground and away from where they can cause damage or injury. The fact is lightning wants to be absorbed into the surface of the earth. To protect ourselves, our homes and businesses and everything inside, we need to give lightning a path to the surface of the earth that bypasses things we want to protect. Doing this correctly requires a properly designed, low-resistance grounding system. Many buildings have grounding systems that meet electrical codes, but many of these systems were installed when codes were not strict and detailed. Many of these systems have been added to and modified by different contractors over the years, without a thorough understanding of grounding as a total system. Grounding and its maintenance is commonly taken for granted. A total systems approach to lightning protection is needed for every electrical installation, for more information visit tiefenerder.
The ground rod provides a termination point for many devices, and is usually connected to a ground bar by a single large conductor. A ground bar is generally used to prevent running cable from every device out to the ground rod. This saves a considerable amount of wire, and eliminates the clutter of multiple connections directly on the ground rod. An interesting note, one of the growing applications for ground bars is in home theater systems. Individual ground wires connect the valuable video and sound equipment to a ground bar. This ground bar is then connected to a copper clad rod buried in the earth.
The major considerations when choosing a ground rod are:
. The number of connection locations currently needed.
. The number of spaces needed for future expansion.
. The conductor size and corresponding terminals to be used.
Ground rods are most often sold as a kit, including the copper grounding, standoff insulators and mounting brackets. These start at 2″ X 10″ in size and go up through 4″ X 72″. Most ground rods incorporate a standard NEMA 3 hole pattern for bolted connection to standard compression lugs made by Burndy, Ilsco, Panduit, T&B and others. If a standard ground rod will not suit your application, custom fabricated ground rod are available. Ground rod can also be electroplated to protect the copper rod from corrosion. This is especially important if the copper rod is exposed to the elements.