What CCA is
Copper-clad aluminum, or CCA, uses aluminum conductors with a thin layer of copper on the outside. Aluminum is cheaper and lighter than copper, but it resists the flow of electricity more and it is more brittle.
Why it causes trouble
- Power loss and heat. Power over Ethernet sends electricity down the same cable as data. Higher resistance means more power is lost as heat along the way, and less arrives at the device.
- Shorter working distance. Devices at the far end of a long run may restart or fail to power up.
- Fragile connections. Aluminum breaks more easily when bent or terminated, and it oxidizes over time.
- Standards and code. The industry standards for category cable call for copper conductors, and CCA cable generally does not carry the safety listings that building codes expect.
Why this matters more now
Modern devices draw more power through the cable. The original PoE standard, IEEE 802.3af, delivers about 15 watts. PoE+ (802.3at) delivers 30 watts. PoE++ (802.3bt) delivers 60 to 90 watts for cameras with heaters, high-end Wi-Fi access points, door controllers and displays. The more power you send, the more the conductor matters.
How to tell what you are buying
- The box and jacket should say solid bare copper, with the wire gauge, such as 23 AWG for Cat6.
- Look for a safety listing mark such as ETL or UL, with a file number you can verify.
- Weight is a clue: a 1,000 ft box of copper Cat6 is noticeably heavier than CCA.
- Scrape a conductor with a blade. Copper is copper-colored all the way through; CCA shows silver underneath.
- A price far below the market usually has a reason.
Plenum or riser?
Plenum cable (marked CMP) has a jacket that gives off less smoke and spreads flame more slowly. Building codes require it in air-handling spaces, such as above a drop ceiling used for air return. Riser cable (CMR) is for vertical runs between floors in non-plenum spaces. In medical buildings, plenum is usually the safe choice throughout.