Last Updated on November 1, 2023 by Electricalvolt
Cables have a conductor or group of conductors that carry electric power or electrical signal from one place to another.
The world today is the world of technology. We can’t imagine a world without electrical, electronic, and communication systems. But the one thing that plays a seminal role in the working of these systems is Cables. Cables can be defined as a set of conductors that help us to transmit higher electrical power or electronic and communication signals over hundreds and thousands of kilometers. In this way, the cables help the technology and the people to keep interconnected.
There is no clear definition of a cable based on its making. A single conductor, whether insulated or not insulated, can also form the cable. But usually, by cable, we denote a set of stranded conductors that are insulated from each other and are packed inside a set of insulations to protect them from their surrounding environment.
The internal insulation helps them to stay separated from each other and not to cause any fault or interference. At the same time, the external insulation and armoring is done to keep the entire cable strong and protected from the surroundings like air, water, heat, etc. The surrounding depends on where we intend to install these cables.
Broadly, there are two types of cables – Electrical Cables and Communication Cables.
Electrical Cables, as the name suggests, are used for transmitting huge amounts of electrical power from the generating station to the consumer facility. In Power System analysis, we deal with the making of the electrical transmission cables that are suitable for the work. This cable can transmit power over a small distance of several hundred kilometers. The most critical challenge that remains is that the cable should be able to withstand the bulk amount of power without any significant loss of power within itself.
Merely generating power equal to or greater than the consumer demand will not help until you have an efficient transmission system. The efficiency of the transmission system depends a lot on the quality and making of the cable being used. It can be an AC transmission system, or it can be an HVDC transmission system.
It can be an overhead transmission system facing problems with wind, moisture, snowfall, or heat. On the other hand, it can be an underwater or underground system where maintenance is a big challenge in case of any internal fault.
Communication cables are used to connect electronic devices for communication. These communication devices convert the transmitted signal into electrical signals, which can be transmitted through the cables. On the other side, these systems again convert the electrical signals into images, sounds, videos, etc. The big challenge here is the loss or distortion of the information that may happen in between.
Communication signals carry the transmitted data in the form of electrical pulses. Any stray magnetic field from the nearby power cable or any other communication cable can cause a change or loss of signal. That’s why proper insulation and grading of the communication cables are essential. These range from small USB cables to long-distance optical fiber cables running through the ocean bed.
Types of Cables
Let’s look at different types of cables in detail.
Electric Power Cables:
As we discussed earlier, electrical power cables are used for transmitting bulk amounts of power from one point to the other over a long distance. There is the concern of cable strength, conductive efficiency, and environmental stresses based on which an electrical cable is designed. We know that Copper is the best conductor that is usually used in the field of electrical engineering for machines and systems. So, power cables are made of Copper. However, Copper is costly, as it has a high weight per unit kilometers, forming a more sag in an overhead transmission line. That’s why, instead of Copper, Aluminium cables are used, which are lighter than Copper and help in overall cost reduction.
But Aluminium has a low tensile strength, which is an essential property for a long-distance transmission cable because it has to face strong winds and rain. That’s why these aluminum cables are provided with a steel core at the center surrounded by aluminum conductors. This is known as Aluminium Conductor Steel Reinforced (ACSR).
Most of the overhead cables operating at high voltages are usually not insulated. The conductors within the transmission cables operating at lower voltages have insulations of asphalt-saturated cotton braid, polyethylene, or any other dielectric material. This insulation ensures the conductors don’t short-circuit and keeps the overall system safe.
Underground cables are used where overhead lines can’t be laid down. These cables have aluminum or copper conductors. Mechanical strength is not required to that degree, as in the case of the overhead lines. These lines don’t face the challenge of wind, snow, or rain. However, the outer insulation of the cable must be strong enough so that the conductors don’t come in contact with the ground directly, which may cause unwarranted disbalance in the local power system.
Communication cables are different from the electrical power cables. Power cables operate at a higher voltage, AC or HVDC. At the same time, the communication cables carry electrical pulses at a much higher frequency than the power cables, which operate at a relatively low frequency.
For a communication cable, it is important that the data transmitted through it remains intact and unaltered. It should primarily be protected against stray magnetic fields.
The insulation for a communication cable is similar to that of a power cable. Communication cables consist of aluminum or lead-alloy tubes or a combination of metallic strips and thermoplastic materials.
There are various types of communication cables based on their working.
(1). USB Cables or Data Cables:
These cables are used for transmitting data between two computers or computer peripherals. USB cable is used for connecting computers with mobile phones. HDMI cables are used for better audio and video quality. Similarly, Ethernet cables are used for network connection in a computer.
(2). Co-axial cables:
A coaxial cable is used for transmitting and receiving radio and television signals. It is a two-conductor cable in which one conductor forms a tube while the other is supported with solid insulation at the center.
(3). Fiber-optic Cables:
Fiber-optic cables are used for operating high-speed internet connections. These cables first came into operation in the mid-1970s. These cables work on the principle of total internal reflection.
In a fiber-optic cable, the data is transmitted through light pulses. These light signals are transmitted through thin fibers of plastic or glass from LEDs or semiconductor Lasers. These cables have been laid down in the ocean beds to connect two or more countries for transmitting and receiving data faster.
(4). Telephone Cables:
As the name suggests, these cables have thousands of conductors used for telephone communication. The diameter of these conductors is about 0.05 inch or 0.125 cm.
Overall, cables provide long-distance connections between systems with reliability, consistency, and security over a long period. These cables keep the world interconnected. However, there are a few challenges that these cables pose.
- The installation and maintenance of the cables could be costly, especially in the case of underground or undersea cables.
- With the advancement in technology, we are moving towards wireless technologies. For example, Bluetooth and WiFi connections have replaced USB data cables. Similarly, research is going on in wireless technologies in every field.
- Cables are made of non-biodegradable materials like polyethylene on the outer covering. These can be detrimental to the environment if not correctly disposed of.
- Cables restrict the usage of portable technology. This is making them obsolete, at least in the lower-range technologies.
This is all about Cables and their types.