Archives for June 2014

Earthing electrodes are specifically designed and installed to improve a systems earthing. These earth electrodes must ideally penetrate into the moisture level below the ground level to reduce resistance.

They must also consist of metal conductors (or a combination of metal conductor types), which do not corrode excessively for the period of time they are expected to serve. Earth electrodes include rods or pipes driven into the ground, metallic plates or mats buried in the earth or a copper wire ring encircling the structure.

Underground gas piping or aluminium electrodes are NOT permitted for use as an earth electrodes.

Earth rods are often selected on the basis of their resistance to corrosion. The other major faction in selection is cost. All too often, the cost of a product is seen as the initial up front price, but the real cost is determined by the serviceable life of the ground rod.

Copper Bonded Rod vs Copper Clad Rod

Galvanised steel rods are one of the cheapest electrodes available. However, they are not the most cost effective since they have a relatively short service life.

Solid copper and stainless steel rods have a long service life. However, they are considerably more expensive than galvanised steel rods. In addition to this, solid copper rods are not suited to deep driving into hard ground due to the likelihood of bending.

The copper bonded earth rod offers a compromise between the two. It 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. We recommend copper bonded ground rods over copper clad electrodes because the copper coating will not slip or tear when driven nor will it crack if the rod is bent.

Copper bonded earth rods feature high resistance to corrosion, provide a low resistance path to ground and have good characteristics for deep driving.

The Stainless Steel Option

It is important to note that certain soils and land fill areas may not be compatible with copper. In these situations, stainless steel represents a better option.

Stainless steel earth rods may also be an alternative, where structures or components, such as steel towers, poles or lead sheathed cables are in close proximity to an array of ground electrodes.

In these circumstances, consideration must be given to the consequence of galvanic corrosion. The high cost of stainless steel rods prohibits their widespread use. As shown in the following graphs:

For more information on our copper earthing rods and electrodes, as well as the rest of our earthing and lightning protection products, please contact our Sales Team.

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