When you want to transmit power or information from one place to another, whether you're sending data, video, audio, or control signals, the transmission process takes place over copper communication cables.
Copper cable is a market - proven technology that enables reliable and cost - effective data and power transmission, while also being easy to terminate.
Each layer of the copper cable structure is crucial for transmitting signals and/or power to where it's needed. These layers influence how data and power are transmitted throughout the cable's lifespan. They also affect:
• Safety during a fire in terms of ignition, spread, as well as the amount of smoke released and toxicity.
• Downtime and system performance.
• The cable's performance in harsh environments.
• The ease of cable installation.
Every copper cable contains the following layers:
• Conductor, which enables signal and/or power transmission.
• Insulation, which protects the conductor and separates it from other conductors.
• Sheath, which is used to protect the cable.
Depending on the cable type, copper cables may also include the following layers:
• Shielding, which prevents interference that could disrupt signal transmission.
• Armoring, which provides physical protection for the entire cable.
• Drain wire, which serves as a grounding path.
• Ground wire, which diverts current from the circuit to the ground.
Each layer of high - performance cables is made of high - quality materials, which improves safety and uptime. This level of performance is important if you want to optimize the return on investment (ROI) of your systems and technologies.
Conductor: The Heart of Everything
The conductor of a copper cable is located at the center of the cable and is protected by the other layers. It transmits data signals and/or power from point A to point B.
Two types of conductors can be considered: solid conductors and stranded conductors. They differ in structure and performance.
Solid conductors are made of a single round wire. They are inexpensive to produce and can be bare or coated with metal. They are used for permanent applications because they are not very flexible. Solid conductors can also carry more current than stranded wires of the same diameter.
Stranded conductors are made of a bundle of twisted or braided copper wires. Due to their structure, they have a longer flex life and the ability to withstand bending. As a result, they are more flexible than solid conductors, making them easier to route around obstacles and install in tight spaces.
Insulation: Protecting Signal Transmission
The inner insulation of a copper cable, which is wrapped around the conductor, is located between the conductor and the shielding (if present) or the sheath. This insulation is called "dielectric" in cables with high - frequency performance parameters.
It protects the conductor from environmental threats and electric current. It is a key part of high - frequency data transmission and plays an important role in preventing capacitive losses. It also separates the conductors from each other to reduce electrical interference. However, it cannot prevent electromagnetic interference (EMI).
Two types of insulating materials are used in copper cables: thermoplastics (such as PVC, nylon, PE, PP, LSZH, etc.) and thermosets (such as XLPE, EPR, etc.), also known as cross - linked materials. The installation location of the cable and its operating environment help determine the best type of insulation.
The installation location of the cable and its operating environment help determine the best type of insulation.
Thermoset insulation has a higher temperature rating compared to thermoplastic insulation. Therefore, it is more durable as it can resist cracking, abrasion, corrosion, and water.
Thermoplastic insulation softens when heated.
Shielding: Preventing Interference
In a copper cable, shielding is a metal layer surrounding the conductor. Not all copper cables have shielding. To optimize the cable's effectiveness and ensure reliable signal transmission, it limits signal interference from external sources. It also prevents the cable from being a source of interference to nearby systems or components. For copper cables carrying high - frequency signals or having multiple conductors, inner shielding and individual shielding are used.
Two types of shielding can be considered for copper cables: foil shielding and braided shielding. Some cables use both types to prevent low - frequency and high - frequency EMI.
Foil shielding is made of a thin and lightweight aluminum layer. Although copper foil is sometimes used, it is more expensive. Belden uses a compound of aluminum and polyethylene to improve durability. Foil shielding is more cost - effective compared to braided shielding. They are most suitable for preventing RFI and EMI at higher frequencies.
Braided shielding is made of copper or aluminum strands (depending on the cable) "braided" together to provide excellent mechanical strength and bend resistance. Braided shielding is most effective in protecting against low - frequency EMI.
Some cables use both types to prevent low - frequency and high - frequency EMI.
Drain Wire: Ensuring Proper Grounding of the Shielding System
Shielded copper cables have a drain wire, which is used to establish proper grounding in the shielding system. In these cases, the drain wire completes the circuit from the shielding layer and diverts electrical noise from the circuit to the ground. The drain wire is usually made of tinned copper and is designed to ensure proper conductivity and corrosion resistance.
Whether a copper cable needs a drain wire depends on factors such as the likelihood of noise interference and whether the cable runs with power lines or other EMI sources.
Ground Wire: Providing Electrical Safety
Some cables have a ground wire, which is a dedicated conductor that connects the electrical system to the earth and provides a safe path for excess electrical energy to dissipate. For example, multi - conductor cables sometimes use a ground wire to minimize noise and improve signal quality.
Armoring: Preventing Physical Damage to the Cable
Some copper cables have an additional protective layer called armoring, which is wrapped around the cable to prevent physical damage from crushing or abrasion. Armoring is usually made of steel or aluminum.
If a copper cable is installed in a harsh environment where it is likely to be physically damaged (such as being run over by a forklift, having heavy objects dropped on it, or being chewed through by rodents), then armoring becomes a priority option.
Sheath: Protecting Everything Inside
The cable sheath has several functions. It maintains the internal structure of the cable, protects the cable from environmental conditions. It also helps prevent the spread of fire and the release of smoke.
The sheath prevents degradation and damage, providing a buffer between the shielding and the external conductors.
The sheath can be designed to resist specific environmental factors such as oil, sunlight, or moisture, and comes in different fire - safety ratings.
The cable sheath can also tell you everything about the cable: where it can be installed, the manufacturer, and how easy it is to operate (based on the size specifications).
Similar to the insulation of copper cables, two main types of cable sheath materials can be considered:
• Thermoplastics (such as PVC, FEP, LSZH, etc.)
• Thermosets (such as CPE, EPR, etc.)
The cable sheath material should be selected according to the application and the installation location of the cable.
Copper Cables for All Types of Connections
These seven layers must work together to create a high - performance copper cable. Any inferior material can affect the performance of your cable.
