CCS conductors are metallurgically bonded, combining the best properties of copper and steel. When manufactured using the correct processes and high-quality materials, CCS can surpass the service life of solid copper, even in cases where the steel core is exposed during installation.
For more information, please visit Ziyu.
Compared to solid copper, CCS offers superior break-load strength, greater endurance, and remarkable resistance to corrosion. In fact, CCS conductors often outlast solid copper wire, even when exposed to the elements. CCS conductors have maintained a century-long reputation for durability.
CCS's added strength and resilience have helped engineers optimize power grids for decades. Still, some engineers seek reassurance that CCS is safe for buried applications.
In this article, we’ll address some of the most common corrosion-related questions about CCS.
CCS conductors are designed so that the copper layer makes up most of the exposed surface area. This design puts the copper where it counts—on the outer surface, in contact with soil, air, and connectors. Copper, with its high conductivity and superior corrosion resistance, acts as a shield for the steel core.
While copper does oxidize and turn green over time, this patina actually enhances corrosion resistance, extending the lifespan of CCS. Special soil conditions, such as those containing cinder fill, can accelerate copper corrosion, but these cases are exceptions. In most environments, copper corrodes at an extremely slow rate.1, 2
According to “A Technical Report on the Service Life of Ground Rod Electrodes,” copper corrodes at a rate of only 0. inches per year in typical soil. At that rate, it would take 2,200 years to corrode through the 0.011-inch copper cladding on a Copperweld Century 19 No. 9 conductor!3
Even when steel is exposed, CCS can endure corrosion. In many installations, connectors such as exothermic or swage fully encase the cut ends of a conductor, protecting the exposed steel. However, when the steel is exposed due to improper termination or compromising the copper cladding, it forms a protective rust “scab,” which seals the steel from further corrosion.2
In worst-case scenarios, corrosion advances only a small distance—usually 2-3 times the diameter of the wire—before the rust scab halts further damage. Even when isolated corrosion occurs, the surrounding copper surface remains intact, maintaining conductivity across the length of the conductor. This is the same protective behavior observed in Copper-Clad Steel ground rods and tracer wire over decades of use. Of course, all conductors, including CCS and solid copper, should be handled with care to avoid damage during installation.2
Copperweld conducted extensive testing from to to assess the effects of indentation and scraping/nicking on CCS conductors. The goal was to study the effects of exposed steel in underground applications.4
After five years of burial in various soil conditions, the results were promising:
In , after 49 years of service in a Kentucky substation, Copperweld Century 7 No. 5 CCS conductors were unearthed. The conductors showed no evidence of corrosion beyond typical copper oxidation, and the copper cladding still met ASTM standards.
At the ends of the wires, corrosion formed the expected steel 'scab'. The copper layer remained intact, and there was no visible corrosion between the copper and steel interface.5
The National Bureau of Standards conducted a comprehensive underground corrosion study spanning over 45 years. This research, covering 37,000 specimens in 95 soil types, concluded that CCS conductors with 10-13 mils of copper cladding have an expected service life of 40 to 50 years. However, this estimate is conservative—Copperweld CCS products can often exceed these standards.2
While copper is often seen as the gold standard for grounding, Copper-Clad Steel offers several advantages that make it a better choice for many applications:
Want more information on Copper Clad Steel? Feel free to contact us.
It’s important to note that not all CCS conductors meet the same standards. Inferior products from foreign competitors may fail prematurely due to cracks and gaps in the copper layer, which allow moisture to travel between the steel and copper layer. These products lack the metallurgical bond that defines Copperweld’s CCS.6
Copperweld’s proprietary bonding process ensures a seamless bond between the copper and steel, preventing moisture from penetrating the conductor and leading to galvanic corrosion. This is why Copperweld CCS consistently outperforms other CCS conductors and delivers reliable service for over 50 years.
When discussing the components in an electrical grounding system, we often hear the terms “copper-clad steel” and “copper-bonded steel” used interchangeably.Though it may seem inconsequential, each term represents a different copper plating process, in which the copper is composite on the steel core. In this post, we consider the question, what is the difference between copper-clad and copper-bonded steel?
The reason the two terms are often used interchangeably is because, on a basic level, they appear the same. Both consist of a steel core and copper exterior.
For use in grounding, both products possess the high tensile strength of steel coupled with the corrosion resistance of copper.
Compared to pure copper, the conductivity of these bi-metallic conductors is lower. To match the current carrying capability of copper, the diameter and copper thickness of bi-metallic conductors are increased. Depending on a conductor’s specific application and region, conductivity requirements may differ.
The primary difference between these two types of processes is the way the copper is composited on the steel core.
Copper-bonded steel is manufactured through a continuous electro-plating process of copper over steel core, resulting in a permanent molecular bond between the two materials.
The technique, known as electrophoretic deposition (EDP), creates a homogenous layer of copper over the steel core, regardless of whether the product is a wire, solid conductor or ground rod. The copper layer thickness is measured in unit of [mils].
Copper-clad steel is manufactured by installing two copper strips over a steel core using pressure and heat to form a metallurgical bond. The copper lair thickness is adjusted to the percentage conductivity of pure copper. Most common conductors used in the U.S. are 40% conductivity of copper.
Copper-bonded steel is mainly used in manufacturing ground rods, solid wire and solid conductors. Copper-clad steel is generally used in manufacturing of stranded and solid conductors. Both copper-bonded and copper-clad steel are used in theft deterrent applications where the conductor is exposed. Both technologies are good alternatives to copper with similar corrosion resistance and higher tensile strength.
Ground rods are used all throughout the world for connecting electrical installations to the earth. We have a series of posts that review the considerations for ground rod materials for these applications. Read more at the posts below.
nVent ERICO has the ground rod solution that you can depend on. Download the flyer.
For answers to common questions, clarifications of misconceptions and installation advice, subscribe to the nVent ERICO blog. And after you subscribe, let us know if you have an electrical question you need answered.
For more information, please visit Copper Clad Steel Wire.