Is copper or steel better for grounding?

When it comes to selecting a ground rod, engineers must avoid a one-size-fits-all approach. Different factors&#;material, soil resistivity, location, facility type, size, among others&#;play into the overall efficiency and service life of both the ground rod and overall grounding system. Below we provide key considerations for ground material selection and then compare the most common types.

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Potential Factors to Ground Rod Material Selection

Once the soil and environmental conditions have been assessed, materials should be compared according to their individual performance in the following areas, and their compatibility with your unique situation.

Primary Factors

Corrosion Resistance: Perhaps most influential to the service life of the ground rod, assess materials based on their inherent corrosion resistance to your soil conditions. Depending on salt, sulfate content or pH, different materials will work best.

Cost: The upfront cost of one ground rod material should not be compared directly to another material. Rather, the lifecycle value of two materials should be compared. If one rod is $20 and another costs $30 but the cheaper rod will only last one-quarter as long as the other, the more expensive rod is the more cost-effective choice.

Secondary Factors

Ease of Driving into the Earth: This relates to the material&#;s strength and the soil&#;s hardness. If a ground rod is bent or broken when driven into the ground, it may be more likely to corrode. Also, a damaged ground rod will less reliably provide the most direct path for electrical currents to travel and dissipate.

Copper Theft: Some have called copper theft an &#;epidemic&#; at different times, and ground rods are not exempt. Depending on your proximity to a population and local theft rates, consider the potential cost of replacing stolen copper ground rods and the immediate system inefficiency it would cause. Typically theft is related to conductors and other above-grade materials, but ground rods are not completely exempt.

Conductivity: As a ground electrode, a ground rod&#;s purpose is to provide a physical connection to the earth and provide the most direct path for a current to dissipate. Though conductivity differences are typically minimal between the most common materials, certain conductivity levels are required in specific regions and are important for providing that path to ground.

Comparing Common Ground Rod Materials

Copper-bonded and galvanized ground rods are the two most common types of ground rods throughout most of the world. In certain situations, stainless steel or solid copper ground rods may be installed to meet unique environmental conditions. What is commonly overlooked, however, is the life expectancy of the grounding electrode system compared to the life expectancy of the facility.

Copper-Bonded Ground Rods

Copper-bonded steel ground rods are manufactured through a continuous electro-plating process of copper over a steel core, resulting in a permanent molecular bond between the two materials. This should not be confused with copper-clad steel, as that method is no longer employed for ground rods due to a less reliable bond. 

• Advantages: Based on the extensive National Electrical Grounding Research Project (NEGRP) by the National Bureau of Standards, rods with 10 mils of copper will likely perform well for 40 years or more in most soil types. It offers the best annual cost advantage of available materials in most situations.
• Disadvantages: Though copper-bonded ground rods exhibit great corrosion resistance in most environments, under highly unique environments high in salts or corrosive chemicals, an upgrade to stainless steel may need to be made.

Stainless-Steel Ground Rods

Stainless steel is not a naturally occurring metal like copper, but it is an alloy of iron with at least 10.5% chromium and varying amounts of carbon, silicon, manganese and sometimes other materials. A stainless steel ground rod is created with a layer of oxide to help prevent corrosion.

• Advantages: Due to the oxide layer, stainless steel is more resistant to corrosion than copper. Stainless steel is also very strong and unlikely to bend or break when installed, even in rocky soil.
• Disadvantages: The primary disadvantage of stainless steel is cost. It is primarily used in industrial processing, saltwater environments and other highly corrosive situations when greater corrosion resistance and/or strength is needed. It is also less conductive than most alternatives, although the variance is relatively small in reality.

Solid Copper Ground Rods

Solid copper ground rods are very corrosion resistant (except when faced with salts) and are also very conductive. However, you will rarely see solid copper outside of the Middle East or similar environments because copper is a ductile, soft metal that often bends when driven into soil other than sand.

Another issue with solid copper is that it is extremely expensive when compared to alternatives. Also, copper theft can be a huge problem for solid copper, making it costly to replace these ground rods.

Galvanized Steel Ground Rods

Zinc-coated steel ground rods are on the opposite side of the cost scale from solid copper ground rods. These are the cheapest of common ground rod materials, offering limited reliability in the long term. 

The problem, according to the NEGRP corrosion study mentioned previously, is that galvanized rods with 3.9 mils of zinc should only be expected to last for 10 to 15 years reliably (compared to 40 or more years for copper-bonded rods). Salts, in particular, are likely to corrode the zinc coating. 

Because a lightning protection system is one that installers would prefer to &#;install and forget,&#; only 10 or 15 years of performance is poor. Constant replacement, including material and labor costs, can cause long-term issues and costs for galvanized ground rod users.

Dig Deeper on Grounding Systems

 

Ready to take the next step? To make the best decision possible when selecting ground rods for your application, make sure you read our post about

The 2 Most Important Factors to Weigh When Selecting Ground Rod Material

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You understand how crucial ground rods are to your project. We&#;re not exaggerating when we say properly installed, quality ground rods can save lives. 

But now comes the challenging part of the equation: What type of ground rod to use? Copper or galvanized ground rods?

We&#;ll examine the qualities of both copper and galvanized ground rods so you can make the right decision for your latest venture. Do you have questions? Don&#;t worry. At Southern Grounding, we&#;re dedicated to helping you succeed; it&#;s part of our longstanding history of stellar customer service and superior quality products. We invite you to contact us for a quote to experience what sets us apart from our competitors.

First, let&#;s look at the benefits of copper ground rods.

What Is Better? Copper or Galvanized Ground Rods?

Is Copper a Good Grounding Rod?

Chances are you&#;re familiar with copper&#;s role in electrical wiring&#;it has a long history of being used in electrical systems. It&#;s an excellent conductor of electricity because it has free electrons. These free electrons are vital in producing an electric flow.

There are several facets to consider when evaluating copper or galvanized ground rods. Here are some aspects to consider when using copper ground rods in your project: 

• They have reliable durability and longevity. In fact, depending upon the soil type, c

  opper-clad grounding rods

  can demonstrate excellent performance for 40 years or more. 

• They can cost more than galvanized ground rods. 

• Copper ground rods can be more prone to corrosion than

  galvanized ones.

You&#;ll have to make the decision whether or not to use copper or galvanized ground rods based on soil, level of conductivity, longevity and economical benefit. 

Benefits of Galvanized Grounding Rods

The most obvious benefit of a galvanized grounding rod is its protective zinc coating. This enables it to resist corrosion, making it perfect for the harshest environments.  

You may have heard the myth that galvanized ground rods are inefficient conductors&#;that&#;s simply not true. While copper is a better conductor, its success also depends upon the type of soil and environment.

If you are looking for more details, kindly visit Copper Clad Steel Grounding Rod.