Introduction: Copper UTP and CCA
UTP twisted pair is the most common cable for building local networks, telephony and IP video surveillance systems. When purchasing a 305‑metre coil, the developer or home craftsman encounters two types of conductors: copper and copper‑clad. A copper UTP cable contains conductors of pure electrolytic copper. Copper‑clad, known as CCA — Copper Clad Aluminium, — is an aluminium core covered with a thin layer of copper.
The difference in conductor material determines the electrical parameters, durability and area of application of the line. A copper wire provides low resistance and stability of characteristics over the entire route length of up to 100 metres. CCA attracts by its price, but loses in conductivity, mechanical strength and compatibility with PoE power technologies. Basic information about the design of twisted pair and categories is given in the review about copper UTP cable.
Comparative Table of Copper and Copper-Clad UTP
| Parameter | Copper UTP | UTP CCA (copper-clad aluminium) |
| Conductor material | Electrolytic copper | Aluminium core with copper cladding |
| Resistivity | 0.01724 Ω·mm²/m | About 0.028 Ω·mm²/m (depends on the thickness of the copper layer) |
| Linear resistance of 24 AWG conductor | ~ 0.188 Ω/m | ~ 0.280–0.330 Ω/m |
| Maximum channel length (100 Mbit/s) | 100 m | 70–80 m (not guaranteed, depends on equipment) |
| Maximum channel length (1 Gbit/s) | 100 m | Rarely stable beyond 50–60 m |
| PoE support (IEEE 802.3af/at) | Full, up to 30 W | Not recommended: heating, voltage drop, failures |
| PoE+ / 4PPoE support | Up to 60–100 W | Prohibited by equipment manufacturers |
| Flexibility and resistance to bends | High, the conductor withstands multiple bends | Low, the aluminium core is brittle |
| Tensile strength | High | Considerably lower, easily breaks during pulling |
| Susceptibility to corrosion | Oxidises slowly, the contact remains stable | Aluminium under copper oxidises, especially in a humid environment; copper flakes off |
| Compliance with TIA/EIA‑568 | Yes, certified | No, does not meet the requirements for direct current |
| Cost of a 305 m coil | Higher | 1.5–2 times lower |
| Service life indoors | 25 years and more | 5–10 years, degradation is noticeable faster |
| Recommended area | Permanent networks, offices, homes, data centres, any projects | Temporary connections, short patch cords, budget networks without PoE |
Conductor Material and Electrical Characteristics
The main difference between a copper UTP cable and CCA is the resistivity of the conductor. For CCA it is approximately 1.5 times higher than that of pure copper of the same 24 AWG gauge. This means a greater voltage drop and greater signal losses over the same length. The TIA/EIA‑568 standard establishes the limit values of insertion loss and loop resistance for categories 5e and 6. CCA fits within these limits only over short distances or with an oversized conductor diameter — 23 AWG or even 22 AWG, which masks the problem but makes the cable heavier and disturbs the lay of the twist.
In practice, a CCA network cable 70–80 metres long can provide a gigabit connection only with ideal termination and in the absence of interference. At the same time, the attenuation margin is minimal, and any deterioration of the contact leads to a speed drop to 100 Mbit/s or loss of link. Copper UTP confidently maintains 1 Gbit/s over a full 100 metres, and UTP Cat6 — and 10 Gbit/s up to 55 metres. Installation rules with observance of bending radii and distances from power lines are disclosed in the article UTP installation.
Power over Twisted Pair — PoE
Copper‑clad CCA cable and PoE power are a poor combination. PoE supplies a DC voltage of 48–57 V at currents of up to 600 mA per pair along the same conductors. The increased resistance of CCA leads to conductor heating, additional power losses and, critically, to a voltage drop on the consumer side. A camera or access point may reboot when the IR illumination is switched on, and the switch may detect an overload.
The IEEE 802.3af/at standard requires that the loop resistance of a pair does not exceed 25 Ω. For CCA over 100 metres it often goes beyond this limit. Network equipment manufacturers explicitly state: use a copper cable, not CCA, otherwise the warranty on PoE devices is voided. Therefore, for IP cameras, wireless access points, VoIP telephones with power over twisted pair — only copper.
Mechanical Strength and Installation
The aluminium core of CCA is brittle. When pulled into a corrugated conduit or a cable duct with bends, the conductor breaks, often inside the sheath without leaving visible traces. The line either does not come up or operates with floating errors. Crimping CCA with standard RJ‑45 connectors is also unreliable: aluminium “flows” under the pressure of the contacts, the connection weakens over time, and the resistance increases.
A copper conductor withstands multiple bends and is reliably fixed in the insulation‑displacement contacts of the connector. The installation of copper UTP is simpler, and the percentage of defects during termination is much lower. When laid outdoors, copper wire lasts longer: CCA in a humid environment is subject to electrochemical corrosion at the junction of copper and aluminium, which quickly puts the line out of service. The difference between shielded and unshielded UTP is described in the comparison FTP or UTP.
When to Choose Copper UTP
- Gigabit networks 1000BASE‑T with a route length of more than 50 metres.
- Any systems with PoE power: cameras, access points, access controllers.
- Permanent installation in walls, under the ceiling, in cable ducts — replacing the cable is labour‑intensive, maximum resource is needed.
- Server rooms and data centres where stability at high speeds and installation density are important.
- Facilities commissioned according to SCS standards with a 25‑year warranty — CCA is not certified.
- Industrial sites with vibrations and temperature fluctuations — CCA does not withstand them.
When CCA Is Acceptable
- Temporary networks for a few days: exhibitions, conferences, construction trailers.
- Short patch cords up to 5–10 metres long that do not carry PoE.
- Budget home networks, if the line length is up to 30–40 metres and the speed is not higher than 100 Mbit/s, with no plans for modernisation.
- Telephone lines and alarm systems with small currents where a high frequency is not required.
- Educational projects, prototyping, where price is important rather than durability.
Typical Mistakes in Selection and Installation
- Buying CCA for an IP video surveillance system with PoE. Cameras periodically lose communication, recording is interrupted, diagnostics show a loss of power.
- Permanently laying CCA in walls. After 2–3 years the link degrades, the cable has to be replaced with expensive repairs.
- Crimping CCA with a standard tool without checking the blade height. The contacts either do not pierce the insulation or break the conductor.
- Attempting to certify a CCA line as Cat5e or Cat6. The DC tester shows an excess of the loop resistance, and the line is not certified.
- Using CCA outdoors. Even an outdoor cable with a polyethylene sheath, but with CCA conductors, quickly corrodes due to condensation.
- Choosing CCA for the sake of economy without taking into account the voltage drop over a long route. As a result, the speed at the end device drops to 10 Mbit/s, and the switch records FCS errors.
Frequently Asked Questions
How to distinguish a copper UTP from CCA visually?
A copper cable is heavier: a 305 m coil noticeably weighs more. When stripping the conductor, a silvery aluminium core is visible on the cut of CCA, while pure copper has the same colour throughout the entire cross‑section. When scraping the copper with a blade, white aluminium is quickly revealed on CCA. Also, CCA is often marked in small print as CCA or Copper Clad Aluminium, but unscrupulous sellers may conceal this.
Why is CCA cheaper than copper?
Aluminium is a considerably cheaper metal than copper. The copper coating is thin, the share of copper by mass is only 10–15 %. The CCA production technology is cheaper, and the price is 1.5–2 times lower, which attracts buyers.
Is CCA suitable for a gigabit 1000BASE‑T network?
Over short distances of up to 30–50 metres and with high‑quality installation, it may work. But stability and compliance with the standard cannot be guaranteed. For a critical gigabit line, copper UTP is always chosen.
Which cable is better for video surveillance with PoE?
Only copper UTP Cat5e or Cat6. CCA will not ensure stable power for the camera, especially with IR illumination, and will lead to malfunctions.
Is there CCA of category 6?
The marking CCA Cat6 is found on the market, but such a cable does not pass certification according to TIA/EIA. The frequency characteristics may be acceptable, but the loop resistance and heating under PoE take it beyond the standard.
Can copper UTP and CCA be mixed in one network?
Physically it is possible, the network will operate at the speed of the worst section. But administration becomes more complicated, and problems with PoE can occur unpredictably. It is better to stick to one type on the entire line.
Conclusion
A copper UTP cable is the standard for professional and home networks where speed, reliability and power over twisted pair are required. CCA is acceptable in temporary and budget projects where there is no PoE and the route length does not exceed 30–40 metres. Saving on CCA results in hidden costs for diagnostics and cable replacement at the first modernisation. The range of copper twisted pairs of categories 5e, 6 and higher, as well as shielded versions, is presented in the catalogue cat 5e and other categories. Compliance with standards and careful installation guarantee stable network operation for decades.
