Home » FAQs » CCA vs OFC Wire: How Copper Content Affects Electrical Performance


When selecting copper electrical wire, two main options are CCA and OFC. CCA stands for copper-clad aluminum, while OFC is oxygen-free copper. The copper content and purity affect the wire’s performance and cost. This article examines the key differences between CCA and OFC wire in order to determine the right choice based on the application.

CCA Wire Overview

CCA wire contains an aluminum core making up 90-95% of its total mass, wrapped in a copper cladding that is typically 5-10% of the overall diameter. This design reaps cost savings from using abundant aluminum while utilizing copper’s high conductivity on the exterior. CCA wire has been commonly used as residential branch wiring and in some commercial buildings since the 1960s, thoughpure copper OFC wire is predominant in modern construction.

OFC Wire Overview

OFC refers to oxygen-free copper wire. It is composed of 99.95% pure copper with limited oxygen content, maximizing conductivity. Silver is sometimes added to OFC wire to increase hardness and flexibility. The absence of oxygen enables the wire to better maintain its integrity and copper conductivity over many years of use. OFC wire provides superior electrical and thermal performance over other types.

Comparing CCA and OFC

Here are some key factors to consider when choosing between CCA and OFC wire:

CCA vs OFC Wire

Electrical Resistance

The aluminum core of CCA wire causes it to have a significantly higher resistance per unit length compared to the same gauge OFC wire, around 20-30% higher. This increases voltage drop over long cable runs.

Heat Tolerance

CCA has reduced thermal capacity compared to OFC, especially in smaller gauges. The heat can damage the aluminum core. OFC wire dissipates heat efficiently to withstand high sustained loads.

Installation Considerations

CCA wire requires special precautions when making connections to avoid oxidizing the aluminum. Polarity must be maintained. OFC wire terminations are simpler and more universal.

Flexibility and Bend Radius

OFC copper is highly ductile and can be bent or flexed repeatedly with little chance of fracturing. CCA is much stiffer and more prone to breaking when manipulated due to its aluminum core.

Cost Differences

CCA wire sells for around 25-40% less than equivalent OFC wire. But OFC has a longer lifespan, recoups more value when recycled, and has lower long-term cost per use in many cases.

Choosing the Right Wire

CCA wire – Best for larger branch circuits, feeders, and services where high resistance is less critical. Avoid for voltage-sensitive uses.
OFC wire – The preferred choice for most household, commercial, and industrial branch circuits. Used extensively for boats, RVs, electronics.

Safety Tips

Always exercise caution working with any electrical wiring:

De-energize and test wires prior to handling
Ensure solid, corrosion-free connections
Follow temperature and current ratings
Use overprotection and proper wiring methods
Adhere to all applicable electrical codes


When comparing CCA vs OFC wire, factors like electrical and thermal conductivity, flexibility, and installation concerns should be evaluated. While CCA wire can provide some cost savings, OFC copper is generally the best choice for most electrical wiring applications, residential or commercial. Consider the advantages of each when selecting copper wire types.

Published On: 2023年8月11日Categories: ,