Copper-clad aluminum (CCA) wire is growing in popularity across the United States. This article explains how the UL 486C standard continues to provide a high margin of safety and explores how the Twister® CCA Wire Connector is specifically designed for copper-clad aluminum installations.
Why is Copper-clad Aluminum Growing in Popularity Today?
Copper-clad aluminum is currently experiencing a resurgence driven by modern copper shortages and the accelerating global trend toward electrification. Propelled by new electric technologies, copper prices have surged by over 75% since 2020.
To conserve copper supplies and save costs, copper-clad aluminum wire is remerging as a copper wire substitute. Today’s CCA is a bimetal product composed of a core of AA-8000 series aluminum that is metallurgically bonded to an exterior coating of high-purity copper. According to CCA manufacturer Copperweld, CCA is manufactured by removing the aluminum oxide layer in a controlled environment before bonding the remaining aluminum to a layer of 99.8% O2-free copper. NEC guidelines require this copper layer to equate to at least 10% of the total cross-sectional area of the conductor.
Proponents of copper-clad aluminum emphasize both its economic and practical advantages. CCA today is consistently cheaper to purchase than copper wire. Additionally, aluminum is approximately 70% lighter than copper, making CCA easier to transport, handle, and install.
Yet, the biggest CCA discussions in the electrical community do not involve its price or weight. Instead, questions have been raised around:
- How to maintain code compliance when splicing copper-clad aluminum conductors
- Whether there are specialty wire connectors for copper-clad aluminum
- The long-term reliability of copper-clad aluminum conductors
How to Maintain Code Compliance When Splicing CCA
In National Electric Code (NEC) article 110.14 (B), the NEC covers splicing conductors in electrical installations. This section specifically notes that “conductors shall be spliced or joined with splicing devices identified for the use…”, which typically means that such a device must be certified by an independent testing agency (i.e. UL, ETL, CSA, or another Nationally Recognized Testing Lab) and that this certification is to a UL standard or equivalent. The standard used by the NEC for splicing connectors is UL486C “Splicing Wire Connectors”.
UL486C testing protocols and requirements for copper-clad aluminum have remained largely unchanged since the introduction of CCA in the 1970s. The latest standard for splicing copper-clad aluminum conductors retained its backwards compatibility and essentially tests CCA to the same rigorous standards as pure aluminum wire. This approach is intentionally conservative and provides an extremely high margin of safety.
The combination of advanced wire connector designs with continued strict UL standards ensures that modern connector types are carefully engineered and tested to provide lasting performance. For even greater peace of mind, electricians can look for wire connectors that are not only UL-listed for CCA but specifically engineered to accommodate a higher level of thermal protection.
An example of a twist-on connector with a higher temperature rating includes:
- Twister® CCA and Twister® CCA+ Connector – These new connectors from IDEAL Electrical™ are UL-listed for use with copper-clad aluminum and specifically rated for temperatures up to 125°C. Most twist-on and push-in connectors on the market are rated for 105°C, meaning these CCA connectors are capable of withstanding ~20% higher temperatures.
Copper-plated Springs in the Twister CCA Connector
Another important design feature of the Twister CCA connector involves their copper-plated springs. Every twist-on connector is designed with an internal, coiled steel spring that “bites” on the conductors as they twist together within the insulating outer shell. This biting is necessary to ensure a firm grip and the security of the internal metal-to-metal contact between wires.
Most twist-on connectors use internal springs plated with zinc. The Twister CCA uses proprietary copper-plated springs. This keeps copper-to-copper contact intact even if the spring bites into CCA’s aluminum core during install. For enhanced confidence in their connection, electricians can select wire connectors created with copper plating on the spring instead of zinc.
Is the Twister CCA Connector Durable for Harsh Environments?
The Twister CCA connector also features a durable design. To ensure long-lasting performance, the connector was put through rigorous lab testing designed to simulate long-term usage in harsh environments. After exposing the Twister CCA and CCA+ connectors to 48 hours of salt spray immersion per ASTM B117, IDEAL engineers performed the most rigorous test of the UL 486C standard – the current cycling test.
In a current cycling test, electrical current is applied on and off in one-hour increments for 500 cycles to simulate electrical system performance over the life of the connection. In these tests, the engineers applied 60A across 10 AWG CCA wires spliced with Twister CCA and Twister CCA+. Each test achieved a maximum stability factor of 3.53 or below, which is comfortably within the maximum allowable limit of eight. The lower the stability factor value, the more stable the connection.
In addition, the samples were measured at a range of temperatures from 99 to 110°C across the cycle tests. Most standard twist-on wire connectors are rated for up to 105°C, while the Twister CCA and Twister CCA+ are rated for 125°C. With 20% higher thermal tolerance than the standard, the Twister CCA and Twister CCA+ provide extra headroom to accommodate higher temperatures.
By easily passing these rigorous tests, the Twister CCA demonstrates its long-term durability in even the harshest environments and highest temperatures. Electricians can install these connectors with confidence, knowing the connection is designed to last.
TEMPERATURE, °C
| Cycle # | Sample 1 | Sample 2 | Sample 3 | Sample 4 | Control | Ambient |
|---|---|---|---|---|---|---|
| 25 | 107.69 | 105.69 | 101.69 | 106.58 | 93.41 | 23.16 |
| 50 | 106.00 | 104.41 | 99.48 | 104.59 | 92.81 | 20.95 |
| 75 | 106.72 | 103.93 | 99.93 | 106.27 | 92.12 | 22.41 |
| 100 | 108.59 | 106.79 | 100.37 | 105.64 | 92.93 | 21.26 |
| 125 | 110.72 | 107.81 | 103.64 | 110.45 | 95.17 | 23.63 |
| 175 | 107.96 | 105.31 | 100.42 | 105.76 | 92.37 | 21.60 |
| 225 | 110.37 | 109.53 | 102.52 | 108.36 | 95.16 | 23.29 |
| 275 | 109.79 | 109.09 | 103.54 | 108.56 | 96.11 | 23.61 |
| 350 | 106.60 | 105.24 | 100.19 | 106.37 | 91.55 | 22.50 |
| 425 | 110.88 | 107.48 | 103.43 | 109.74 | 92.20 | 23.15 |
| 500 | 109.79 | 106.81 | 102.19 | 108.15 | 93.04 | 23.61 |
| Sample No. | Max. Temp. Rise, °C | Maximum Stability Factor |
|---|---|---|
| #1 | 87.74 | 3.38 |
| #2 | 86.23 | 2.07 |
| #3 | 80.28 | 3.03 |
| #4 | 86.82 | 3.53 |
| Control | 72.49 |
What Wire Connectors Exist for Copper-clad Aluminum?
IDEAL Electrical offers many different varieties of connectors that are compatible and UL-listed with CCA. This includes the new Twister CCA, a specialty Al/Cu twist-on connector, and select lever and push-in connectors.
Twist-On Style
Our twist-on wire connectors are purpose-built to give electricians added confidence and peace of mind when installing copper-clad aluminum wire.
Twister CCA
The Twister CCA is the only UL-listed connector on the market specifically designed for the needs of CCA. They offer industry-leading thermal protection up to 125°C and a proprietary copper-plated spring. The Twister CCA and Twister CCA+ have passed rigorous UL testing and salt spray testing to ensure safe usage with both copper-clad aluminum and copper conductors, though they are not designed for reuse with copper-clad aluminum.
Additional key features of the Twister CCA include:
- Easy Identification: A bold blue housing catches the eye and makes these UL-listed connectors easy for inspectors to spot.
- Wide Wire Range: The two different connector models cover a wide wire range from two #20 AWG to four #10 AWG wires. Twister CCA supports 12 and 10 AWG copper-clad aluminum and 20 to 10 AWG copper, while the larger Twister CCA+ supports 12 and 10 AWG copper-clad aluminum and 14 to 10 AWG copper.
- High-Leverage Wings: Designed for ease of installation, the comfortable wings on each side of the connector provide extra grip and reduce hand fatigue during the application process.
Twister® Al/Cu Wire Connector
The Twister Al/Cu Wire Connector is designed for aluminum-to-copper retrofits. This specialty twist-on connector includes an entry cap filled with an antioxidant compound to prevent aluminum corrosion. While primarily intended for aluminum, the Twister Al/Cu also performs effectively in CCA-to-copper connections.
Push-In and Lever Style
Select push-in and lever connectors from IDEAL Electrical are also UL-listed for copper-clad aluminum connections. In push-in and lever designs, the CCA conductors are pressed against a conductive buss with a stainless-steel spring that provides the clamping force needed to keep the connection stable.
Push-In Connectors
- Specific push-in connectors from IDEAL Electrical are UL-listed for copper-clad aluminum connections. Push-ins allow for convenient and easy application; users insert conductors into the housing with minimal force required. The IDEAL model 30 series connectors in 2-port, 3-port, 4-port, and 3-port 10 AWG 30A versions support copper-clad aluminum to copper connections.
Lever Connectors
- Certain lever connectors are also UL-listed for CCA applications. Available in 2-port, 3-port, and 5-port options, the new 10 AWG lever connector from IDEAL Electrical supports copper-clad aluminum to copper connections. This connector also features a clear housing for visual inspection of work and a built-in locking mechanism for connection security.
Copper-clad Aluminum Wire and the Future
As the global demand for copper continues to surge, the electrical industry faces a growing copper wire shortage. More American electricians and electrical contractors are turning toward copper-clad aluminum conductors as an alternative that conserves costs.
Copper wire will remain the backbone of electrical installations. But as copper shortages intensify, copper-clad aluminum provides a reliable and code-complaint solution when paired with the right materials and installation practices. Understanding its capabilities and the latest connector innovations are key to navigating the future of electric wiring.
Explore CCA Twister Connectors
