Metal conductors are an important part of wire and cable products. Copper and aluminum, as the basic materials of wire and cable conductors, have been widely used in the power industry all over the world. Conductor materials should not only meet the application requirements in terms of performance, but also reduce product costs, so as to conform to the background of the era of comprehensive utilization of resources, energy conservation and environmental protection.
As early as the s, civil construction in the United States and Canada began to use pure aluminum conductors in power cables. Due to the lack of physical, mechanical and electrical properties of pure aluminum, and the installation and laying process at that time was not yet Imperfect, accidents often occurred in application. After World War II, U.S. cable companies, U.S. Underwriters Laboratories and related research institutions began to devote themselves to the development of all-aluminum alloy conductors.
In , the first cable with -series aluminum alloy as the conductor was successfully developed, and then began to be promoted in the United States, Canada and other countries. It is mainly used in military bases, residences, public buildings and wind farms, and its production has been standardized.
The all-aluminum alloy conductor is a new type of energy-saving product. It is a high elongation aluminum alloy material, which is made by adding copper, iron, magnesium and other elemental materials into pure aluminum, and through compression stranding technology and metal annealing treatment to tighten the existing voids in alloyed aluminum. The all-aluminum alloy conductor makes up for the shortcomings of the previous pure aluminum cables. Its insulation material uses flame-retardant silane cross-linked polyethylene, and the outer layer adopts metal chain armor structure, so the gap between the conductive performance of the all-aluminum alloy conductor and the copper core cable is greatly reduced, but the creep resistance, bending performance and corrosion resistance are greatly improved, which ensures that when the cable encounters overload and overheat during use, stability can be maintained for continuous performance.
In the production process of the all-aluminum alloy conductor, advanced compaction technology can make the filling coefficient of the conductor reach 93%; and the all-aluminum alloy conductor is made of silane cross-linked polyethylene, this insulation only needs PVC 2/3 of the thickness can far exceed the conventional insulation performance. However, the filling coefficient of copper can only reach 80% in general, and the commonly used insulation is polyvinyl chloride, so the outer diameter of the all-aluminum alloy conductor can be the same as that of the copper core cable by only increasing by 11% on the basis of the copper core cable. It can be seen that all-aluminum alloy conductors can be used normally without changing the original pipeline design of copper core cables.
All aluminum alloy conductors can completely replace copper core cables in terms of performance, and all aluminum alloy conductors can basically be used where copper core cables can be used. Compared with copper core cables, under the premise of consistent electrical performance, the conductors of all aluminum alloy conductors can resist creep, with the characteristics of high flexibility, strong ductility, low rebound, and stable connection. Its insulation has the characteristics of high temperature resistance, anti-combustion, anti-aging, strong durability, low-carbon and environmental protection. Its armor layer is made of aluminum alloy with interlocking armor, which has a self-locking form. Strong and tough armor layer ensures that the cable can withstand strong destructive forces from the outside world. Its outer sheath is made of lead-free and cadmium-free PVC material, which can be installed under humid environmental conditions or directly buried in cement. In general, the all-aluminum alloy conductor has better bending performance, ductility and creep resistance performance basically the same as that of copper core cable, light weight, energy saving and environmental protection, etc., which reduces the wear and tear between equipment and cables, making Installation work is easier. Under the premise of providing the same electrical performance, the weight of the all-aluminum alloy conductor is half of the copper core cable. Its cross-section is 1.3 times bigger than the traditional copper core cable, and the price is 40% lower than the traditional copper core cable. The comprehensive cost performance advantage is huge.
When the surface of aluminum is in contact with air, a thin and strong oxide layer is formed. The surface of this oxide layer is very resistant to various forms of corrosion, forming the anti-corrosion properties of aluminum itself. Rare earth elements further improve their corrosion resistance, especially in electrochemical corrosion performance. In some sulfur-containing environments, such as in some places such as railway tunnels, the corrosion resistance of aluminum alloys has more obvious advantages than copper.
When the all-aluminum alloy conductor is annealed, some elements added to it produce high-strength creep resistance, which greatly improves its connection performance. Especially the key is that even when the current is overheated and overloaded, the possibility of creep of the all-aluminum alloy conductor is very small, which ensures the stability of their connection. So the electrical connection of all aluminum alloy conductors and copper core cables is equally reliable in stability.
Under the premise of the same electrical performance between the all-aluminum alloy conductor and the copper core cable, the cost price of the all-aluminum alloy conductor is about 13% to 20% lower than the copper core cable, and there is also a saving in installation costs. Due to the high bending performance and lighter weight of the all-aluminum alloy conductor, especially the installation of aluminum alloy belt interlocking armored cable does not require bridges and pipes, saving a lot of steel, and the installation cost can be reduced by about 20%.
1. Since the resistivity of the all-aluminum alloy conductor is lower than the copper conductor, the same electrical function can only be achieved if the cross-section is larger than the copper cable. So the outer diameter of the finished product is 10% to 20% larger than the copper cable. This is the main disadvantage of all aluminum alloy conductors. But whether the link of the equipment or the layout of the cable, this size difference is within the allowable range of the design of the pipe.
2. The scope of application has certain limitations. In the special application environment with high temperature resistance above 700 ℃, the all-aluminum alloy conductor should not replace the copper core cable.
3.The production process of all-aluminum alloy conductors is different from traditional copper core cables. The production process and auxiliary materials cost are relatively high, and the core of its quality assurance is still in the conductors. Therefore, the process of manufacturing all-aluminum alloy conductors still needs to be improved.
The good mechanical properties and conductive properties of aluminum alloy power cables make it widely used in various fields of the national economy, such as high-rise buildings, subways, airports, tunnels, underground buildings, etc., and can also be used in metallurgy, coal mines, Shipbuilding, nuclear power plants, aerospace, military and other industries, as well as automobiles, public transportation facilities, etc., have very promising market prospects and attractive prospects, and will surely become the mainstream of power cable development in the future.
Don Schultz: Welcome back to the Low Voltage Lowdown podcast! I'm Don Schultz, Senior Technical Advisor at trueCABLE, and joining me today is Technical Analyst Dave Harris. Today, we have an important topic to discuss – the ongoing debate between copper-clad aluminum (CCA) and solid copper Ethernet cables in the world of networking. Whether you're a homeowner or a commercial installer, it's crucial to be well-informed when it comes to making the right choice. In this article, we'll dive deep into the technical aspects, legal implications, and potential risks associated with CCA and solid copper Ethernet cables. By the end, you'll have a clear understanding of why CCA is not recommended for Ethernet cable installations. So, let's dive right in and address the many questions we receive about copper clad aluminum! If you prefer audio, you can also listen to the podcast below!
Dave Harris: CCA, short for copper-clad aluminum, is essentially an aluminum conductor with a thin copper coating. Despite its resemblance to pure copper wire, CCA does not offer any increased conductivity or reduced resistance compared to regular aluminum wire. However, the advantage of CCA lies in its capacity to prevent corrosion when connecting copper and aluminum wires together, particularly in applications like single center conductor coaxial cable for cable TV. As long as CCA meets industry standards and guidelines, it is permitted for use. Nevertheless, it is crucial for CCA to be clearly labeled on both the container and insulation to avoid any misrepresentation of clad aluminum cable as copper.
Dave Harris: While CCA may have its usefulness in certain electrical installations, it is strictly prohibited for use in copper twisted pair category cable, commonly known as Ethernet cable. The National Fire Protection Act clearly states that communications cables, other than coaxial cable, must have copper conductors. This means that CCA Ethernet cables cannot be labeled as a categorized cables since they do not meet the necessary standards. Using CCA in Ethernet cable installations not only violates industry regulations but also poses significant risks in terms of performance, safety, and legal implications.
When it comes to data transmission, CCA fails to meet the standards set by organizations like the Telecommunications Industry Association (TIA). Testing conducted by Fluke Networks and other industry leaders indicates that CCA consistently fails tests for DC resistance and insertion loss, making it unsuitable for twisted pair data transmission. The higher resistance of aluminum compared to copper negatively affects the performance of CCA cables, leading to signal loss, increased interference, and reduced data transfer speeds. This means that CCA cannot achieve the desired category rating required for reliable Ethernet connectivity.
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Beyond performance issues, CCA Ethernet cables also pose safety hazards. Due to the high resistance of aluminum, CCA is not compatible with proper Power over Ethernet (PoE) applications. The higher resistance causes voltage drop, which can damage devices that rely on PoE for power and data transmission. Additionally, the installation of CCA Ethernet cables creates a fire hazard. The lower melting temperature of aluminum compared to copper increases the risk of flame ignition, especially in environments where high-power PoE is used. The National Electric Code strictly prohibits the use of CCA Ethernet cables due to these safety concerns.
To gain a deeper understanding of the differences between CCA and solid copper conductors, and why you shouldn't use CCA, we highly encourage you to check out our Fluke DSX CableAnalyze cable test we performed to show you the exact difference in performance.
Dave Harris: Although CCA Ethernet cables may visually resemble solid copper cables, there are ways to differentiate between the two. The packaging and cable jacket of CCA cables must be labeled as CCA according to industry regulations. Additionally, CCA cables are significantly lighter than solid copper cables, making them less suitable for certain applications. Another telltale sign is the unusually low price of CCA cables compared to their solid copper counterparts. While these visual cues can help identify CCA cables, the most reliable method is certification testing. CCA cables fail certification tests for DC resistance, balance, and insertion loss, making it clear that they are not true Ethernet cables.
Dave Harris: As an installer, it is essential to understand the legal implications of using CCA Ethernet cables. While it may be legal to purchase CCA cables, it is illegal to install them for copper twisted pair Ethernet cable applications. Commercial installers using CCA cables face severe consequences, including code violations, fines, and delays in obtaining occupancy permits. Installers may be held liable for their actions, even if they were unaware of the illegality of CCA cables. Similarly, manufacturers selling CCA cables falsely labeled with Ethernet category ratings may violate advertising laws, opening themselves up to legal action.
Don Schultz: Now, Dave mentioned that there are certain applications where CCA is allowed. And that's true. For example, there is a communications cable where CCA and copper clad steel (CCS) is allowed, and that would be coaxial Series cable. However, it's still preferable to use solid copper, especially for satellite installations that require voltage to the LNB. Using CCA or copper-clad steel in satellite installs is not ideal and can lead to issues under-volting the LNB.
It's worth mentioning that copper clad aluminum can be used in certain electrical installations, but the cable box must clearly state that it is copper-clad aluminum. This is typically seen in specific electrical applications. However, where CCA is absolutely never acceptable is in copper twisted pair category cable. If you have a so-called "Ethernet category whatever" cable that claims to have copper-clad aluminum, it cannot be considered an Ethernet or category cable at all. The TIA standard specifically forbids the use of anything other than copper in these cables.
So, if the standard doesn't allow it, how can you label it as a category cable? The National Fire Protection Act is very clear on this matter. I'm going to quote section 800.179, which states, "Communication wires and cables shall be listed and marked in accordance with table 800.179 conductors in Communications cables other than in coaxial cable shall be copper." This is the law.
Now, you might be wondering why you can still buy CCA if it's not allowed. Interestingly, there is no law against selling or buying it. However, there is a law against installing it. As a homeowner, you might get away with using CCA until you need to replace or upgrade your wiring for other reasons. But for commercial installers, it's a different story. Using CCA can lead to warranty replacement problems, contractual violations, and if your local code inspector discovers it in a commercial building, you'll be in serious trouble.
The sequence of events is usually as follows: the inspector will come out, discover the use of CCA, and start asking questions. They will question your decision and reasoning. Then, they may begin issuing fines per day until you remove the CCA and may even deny you an occupancy permit for the entire building until it's removed. You'll then have to schedule another inspection, which could cause further delays. In addition to the cost of replacing the cables, you'll also lose your reputation and your customers' trust. The consequences can be significant.
So, it's crucial to be aware of the legality and potential repercussions of using CCA. It's always best to comply with the standards and use copper conductors in communication cables to avoid any legal or safety issues down the line.
Don Schultz: Now, let's get into some fun stuff. Let's get away from the brimstone falling out of the sky for a moment and talk about some nonsensical claims made by certain CCA manufacturers. There is one particular manufacturer that's out there that likes to say that their CCA is somehow “better and more acceptable than other manufacturers' CCA” because they happen to use more copper coating on the aluminum than their competitors. Again, I don't care what percentage they say they're using or if it's more or less, the standard and the law does not allow for it to be sold as category twisted pair Ethernet communication cable, period. It doesn't matter.
Another claim we’ve seen is, "However, new evidence is proving that CCA has definite benefits over pure copper in certain applications." That's a really loaded sentence there. What exactly are these benefits? What empirical evidence have they done or have? What testing do they have to show? What entity do they submit samples to? UL or cETLus? The answer is they couldn't have because that would never be accepted.
The next claim we've seen is, "While copper-clad aluminum isn't always the best solution, CCA allows cables to utilize all the benefits that copper has to offer while maintaining a much more affordable price tag and helping to protect the world's limited supply of copper." I don't even know where to begin with this one other than I'll just pick some parts out. Installing CCA communications cable does not allow you to utilize all the benefits of copper. That's a flat out misrepresentation. It's true that it has a much more affordable price tag. That part of the sentence is true. But helping to protect the world's limited supply of copper, I mean… this is just a grasping at straws contest now. The problem is that if you end up having to rip all of this stuff out and replace it with the good stuff, I don't think it benefited the climate or the environment at all. I think you just doubled the amount of stuff going into the landfills.
The last claim we've seen is regarding the "skin effect". It is suggested that the skin effect, where electrons run across the top of the copper, renders the underlying aluminum irrelevant in CCA cables. However, this claim is incorrect. CCA cables have a higher DC resistance and DC resistance unbalance problem that prevents them from meeting testing standards. The cable fails to meet expected standards and cannot be certified. In addition, the DC resistance of copper-clad aluminum is 55% higher than that of pure copper. The claim that using more copper in CCA cables makes them superior is also misleading. The ampacity of the underlying aluminum remains the same, regardless of the copper percentage. As a result, CCA cables fail category testing and pose hazards, particularly for PoE devices. Therefore, the claim that the skin effect negates the issues with CCA is unfounded.
So anyway, generally speaking, copper-clad aluminum is going to get you into a great deal of trouble. If not right away, then down the line. And you're not going to save any money at all in your project because you're going to end up having to pull it all out and replace it. That's going to obviously cost more in materials and more time. And if you were putting it in your cabling prior to covering walls, for example, now you may not even be able to replace that cable easily. You may be demoing walls to get it out. Someone please explain to me exactly how that's going to end up saving you money?
Don Schultz: In conclusion, it is important to avoid using copper-clad aluminum cables for copper twisted pair Ethernet applications. While it may be legal to purchase CCA cables, it is not legal to install them for this purpose. The limited situations where CCA can be used are specific and rare. Considering the higher DC resistance, failure to meet testing standards, and potential hazards, it is strongly advised to steer clear of CCA. Instead, opt for reliable and certified solid copper cables. To stay up to date on everything low voltage, We encourage you to check out our very own Cable Academy that offers extensive educational content to learn more about cables and their proper usage. Alternatively, you can also view our recently launched Help Center, where you can find in-depth information on everything trueCABLE including all of our cables and connectors. If you can't find the answer you’re looking for, please don’t hesitate to reach out. We’re here to help.
Happy Networking!
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