Different types of earth rods
Types of earth rods
Solid copper earth rods
It is made from high conductivity hard drawn copper
Advantages
It is used for soil with high moisure and salt content and is very corrosive
It is used where high fault currents are expected .
Disadvantages
The solid copper is a ductile metal that will often bend when driven into soil so it is not suitable for use when a deep driving into the ground is needed
Copper bonded steel earth rods
Advantages
It is considered the most efficient and cost effective type of earth rods.
It has high mechanical tensile strength and resistance to corrosion at lower cost as compared to other types of earth rods (solid copper or stainless Steel)
The rod is usually treated to avoid oxidation of the copper bonding.
Galvanized Steel earth rods
The zink coating will delay the corrosion of the steel bar by providing a sacrificial barrier.
Advantages
It has good corrosion resistance and conductivity.
Disadvantages
It has the lowest resistance to corrosion
It has the lowest electrical conductivity and poor current carrying capacity.
Applications
Stainless steel earth rods
Advantages
It is used when extremely corrosion resistance and high mechanical strength is needed .
The stainless Steel earth rod is treated with an oxide layer that makes it more resistant to corrosion than copper.
It is used to overcome many of the problems caused by the galvanic corrosion that can take place between buried dissimilar metals being in close proximity to each other .
Stainless Steel earth rod provides high mechanical strength so it is unlikely to break or bend when driven into the ground even in rocky soil.
Disadvantages
It is the most expensive of all types of earth rods .
The current carrying capacity of steel earth rods is poor compared with copper earth rods
Application