Copper or Aluminium? Selecting the right conductor material

Copper, aluminum, or CCA?
When selecting cables, choosing the right conductor material is a critical decision—one that affects electrical performance, weight, durability, and cost. Here's a breakdown of how each material compares and where it makes the most sense to use.

Copper: The reliable standard

Copper is the go-to conductor for most cables and wires—and for good reason. It offers excellent electrical conductivity, high tensile strength, flexibility, ease of processing, and recyclability. These qualities make it a reliable choice across a wide range of applications, including industrial equipment, building automation, mobility solutions, and energy distribution. Even in harsh environments with frequent bending, vibration, or mechanical stress, copper maintains consistent, dependable performance.

Aluminium: A slight cost advantage

Aluminum conductors are typically used when weight reduction is a key consideration—such as in long-distance transmission lines, wind turbines, or vehicle battery systems. While aluminum is much lighter than copper, it offers only about 63% of copper’s conductivity. As a result, larger conductor cross-sections are required to achieve the same ampacity. Aluminum is also more brittle, more prone to corrosion, and less mechanically durable. Its use demands specialized knowledge along with the proper connection techniques and tools to ensure safe and effective installation.

Example comparison of two conductor cross-sections with similar conductance (IEC 60228, Class 2):

• Copper conductor 150 mm²: approx. 1341 kg/km
• Aluminium conductor 240 mm²: approx. 723 kg/km

• A 30-40% reduction in weight

CCA—Copper-Clad Aluminium: A deceptive compromise?

Copper-clad aluminum (CCA) conductors are aluminum cores coated with a thin layer of copper. Originally developed for antenna applications to take advantage of the “skin effect”—where high-frequency AC currents flow primarily along the conductor’s surface—this technology has limitations when applied to general electrical power. CCA conductors are significantly less conductive than pure copper, making them a poor substitute in many applications where reliable electrical performance is critical.

Despite the drawbacks, CCA cables continue to flood the market, particularly from low-cost manufacturers in Asia. These cables are frequently positioned as budget alternatives for specific low-voltage or non-critical applications, such as:

• Speaker cables
• Power cables for HiFi car audio
• Network cables (patch cables)

Difficulties in use:

• A 2.5 mm² CCA conductor is roughly equivalent to a 1.5 mm² copper conductor.
• Higher voltage drops and heat generation with power over ethernet
• Risk of fire if fuses in vehicle HiFi systems aren't properly protected
• Its use in company networks does not conform with standards (forbidden by TIA and IEC)

Comparing technical data: