Grounding System
From ground rods to ground enhancement material (GEM)
Get the Facts to Maximize Your Grounding System:
To ensure you get the most out of your grounding system, you need to have all of the facts. Which ground rod should I choose? How will ground conditions affect my grounding system? How can I maximize my system’s performance and save money, too? Turn to ERICO for the support you need.
Ground Rods: What Do the Experts Say?
When an ERICO brand of copper-bonded ground rod (top) and a copper-clad rod are subjected to the same pressure load, the inferior copper-clad rod (bottom) develops cracks and creases to the outer sheath.
Damage to the rod negatively affects its serviceable life and puts the integrity of the entire electrode at risk.
The top ground rod is galvanized steel, 19mm. The bottom ground rod is copper-bonded 15mm. Both ground rods were driven into the soil vertically at the Pecos testing site in Las Vegas, NV in December of 1992.
Both ground rods were exhumed from the site in April 2004.
The loss of zinc on the galvanized steel rod resulted in excessive corrosion of the steel.
The copper-bonded steel ground rods showed minimal corrosion.
This is a galvanized steel ground rod driven into the ground vertically at the Pawnee testing site in Las Vegas, NV.
This ground rod was buried from May 1992 until March 2003.
The loss of zinc resulted in excessive corrosion of the steel. One area is reduced from a 19mm diameter to approximately a 6mm diameter due to the corrosion.
The eventual failure would result in a potentially catastrophic loss of ground.
ERICO copper-bonded ground rod (Top) Copper-clad ground rod (Bottom)
Excavated after 12 years
This is a galvanized steel ground rod driven into the ground vertically at the Pawnee testing site in Las Vegas, NV. This ground rod was buried from May of 1992 until March of 2003. The loss of zinc resulted in excessive corrosion of the steel. One area is reduced from a ¾” diameter to approximately a ¼” diameter due to the corrosion. The eventual failure would result in a potentially catastrophic loss of ground.
Benefits of GEM: Connections, Testing, and Trusting the Experts
The ERICO brand of copper-bonded ground rod has an electrolytic coating of copper deposited over a layer of nickel. This process helps ensure a long-lasting molecular bond between the copper layer and steel core. Pentair recommends copper-bonded ground rods in most soil conditions, because the copper coating will not slip or tear when driven, nor will it crack if the rod is bent. Copper-bonded ground rods have a high tensile, carbon steel core, which is ideal for deep driving, and they provide a low resistance path to ground.
When compared to stainless steel or galvanized rods, copper-bonded ground rods are a cost-effective option over the service life. It is important to note that certain soils and land fill areas may not be compatible with copper. In these situations, stainless steel rods can be used. However, the high cost of stainless steel rods often prohibits their widespread use.
The NEGRP report also positively supported the use of GEM for a grounding system. The report showed that vertical electrodes in GEM displayed minimal corrosion.
ERICO brand of GEM can be applied around the conductors in a grounding system. GEM helps to reduce soil resistivity and lower ground impedance, which facilitates the dissipation of lightning energy into the earth mass. GEM is particularly useful in areas of moisture variation, sandy soils and rocky ground.