What is an Electric Cable?
An Eclectic cable is a cable used to distribute and transmit electrical power. The Electric Cable is used to transmit high voltage where overhead lines are impractical to use.
An electric cable is made of three kinds of things those are –
Conductor
Dielectric
Sheath
The conductor provides the conducting path in the Electric Cable. The insulation or dielectric withstands the service voltage and isolates the live conductor with another subject.
The sheath protects the Cable from all external influences like chemical and fire attacks. Also, it prevents moisture from harming the electric Cable.
Introduction
Electric cables are usually made of copper Because electricity moves well in copper. Copper is not as expensive as silver, making the work easier. Sometimes aluminum is used in cable making because it is cheaper than copper. A cable is made when many wires come together.
Electrical cables are shielded conducting wires, used in the generation, transmission, and distribution of electrical power. Electrical cables, in a circuit, are joined through connectors. A combination of cables and connectors is known as a cable assembly.
The conducting wire in a cable carries electricity whereas the insulator and the sheath give protection to the cables from unintended circuit paths and chemical reactions. Cables can be classified into various categories, depending on their different uses and structures. Some types are coaxial cables, twisted pairs, optical fibers, patch cables, power cables, data cables, etc.
Components of a Cable
A cable should have the following three components,
Conductor: The conducting part is used to transmit electricity. Extensively used conductors are copper and aluminum.
Insulator: To keep the conductors separated from each other and prevent unintended paths for current flow (e.g. short circuit), the wires are shielded with insulating materials. Various synthetic polymers are used for this purpose.
Sheath: It is yet another layer to give protection to the wires from chemical reactions with the atmosphere. A common material for the sheath is PVC (polyvinyl chloride).
Classification of Cables and Colors
Different colors of wires are used for different purposes. In DC circuits, the colors are,
Red: Wires for positive current.
Black: Wires for the negative current.
White or Grey: Ground wires.
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For AC circuits (power 120/208/240 Volts),
Black: Phase 1 lines are colored black. These wires are for power generation.
Red: Phase 2 or transmission wires.
Blue: Phase 3 or power distribution wires.
White: Neutral wires.
Green or Green with Yellow Stripes: Ground wires.
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Various Types of Electrical Cables and Their Uses
Network cables: Network cables are used to connect different components in a networking system. Based on the size and structure of the systems, different types of network cables are used.
These are listed below,
Coaxial Cables: These cables (also called coax) consist of a conducting core, surrounded by another conducting layer. Both the layers are separated by a dielectric or insulator in the form of a coaxial cylinder. The entire setup is given an outer jacket for protection. Coaxial cables are used to transmit high-frequency signals with minimal energy loss in several devices like televisions, radio transmitters, antennas, and many more.
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Twisted Pairs: Two cables are twisted together and color-coded. As compared to a pair of untwisted cables, the twisted one has less possibility of crosstalk or interference. These cables are used in ethernet networking systems.
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Optical Fibers: Fibers have glass cores surrounded by some protective layers. These cables use total internal reflection to transmit light and therefore have almost zero energy dissipation. Optical fiber has a core inside a cladding. The cladding is optically rarer than the core. The transmitting electromagnetic wave reflects in the core-cladding interface several times. Optical fibers can be classified further into two types, which are multi-mode fiber (short-range) and single-mode fiber (long-range).
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Patch Cable: Patch cables are used to connect or “patch” different devices.
Internet Cables: Types of internet cables are ethernet cables (shielded and twisted). Ethernet cables connect a computer or a game console to a modem. These cables transfer data across the internet. Some cables, called “cross-over cables” can connect two devices.
Power Cables: Power cable assemblies are used to transmit electrical power. These can be used as permanent wiring in buildings. Power cable types are the power cord, extension cable, twisted, shielded, extensible, communication cable, and many more. These cables can be used overhead or buried underground.
Types of Computer Cables: Types of computer cables are power cables and data cables. Power cords are used in the charging of a computer or a laptop. Data cables can be of DVI, VGA, or HDMI types. Data cables are used to transfer multimedia from one device to another.
Ribbon Electric Cables
Ribbon Electric Cable is made of multiple insulated wires running parallel with one another. It is used for the transmission of multiple data simultaneously. For example, it says that the CPU with the motherboard is connected by the Cable and is generally used for networking devices' interconnection.
Shielded Cables
Shielded Cable is made of 1 or 2 insulated wires covered by a woven braided shield or aluminum Mylar foil for better signal transmission and removing irregularities in radio frequency of power and external interference. These cables transmit high voltage electric current. A shield is protecting it.
Twisted Pair Cables
Twisted Pair Cables has two or more insulated copper wires twisted with each other and coded with color. Twisted Pair cables are especially used in telephone cables. The number of wires can measure the resistance to external interference.
Coaxial Cables
Coaxial Cables are made of solid copper or steel conductor plated with copper. The plated part is enclosed in the metallic braid and metallic tape. This entire Cable is covered with an insulated protective outer jacket. In computer networking and audio-video networking, this kind of Cable is used.
Fibre Optics Cable
Fibre Optics Cable transports optical data signals to the receiving device from an attached light source. One must be pretty much aware of optical fiber and its uses in a wide variety of applications.
Did You Know?
Copper is used as conducting wires in electrical cables because copper is a good conductor and also cheap.
Cable sheaths protect and hold the conductors from chemical reactions.
Most cables have multiple insulating layers and sheaths.
Polyvinyl chloride, butyl rubber, polyethylene, impregnated paper, etc. compounds are used as the insulating layers in different cables.
Multi-mode optical fibers can transmit signals of multiple wavelengths and are used for short-distance transmissions.
Single-mode fibers are used for the transmission of a particular frequency.
Different kinds of glass were used as the core of the optical fiber. Nowadays, transparent plastics are used in the core.
Power cables come in various sizes depending on the purpose of use.
Twisted pairs have reduced energy dissipation and less interference.
Thomas Edison invented the electric Cable.
FAQs on Types of Cables
1. What is an electric cable and what are its essential components?
An electric cable is a structure designed to transmit electrical power or signals from one point to another. It is fundamental in everything from household wiring to large-scale power distribution. Every electric cable consists of three primary components:
- Conductor: This is the path for the electric current, typically made of a highly conductive metal like copper or aluminium.
- Insulation (Dielectric): A non-conductive layer that surrounds the conductor to prevent short circuits and protect from electric shock. Materials like PVC or polyethylene are commonly used.
- Sheath: The outer protective layer that guards the cable against physical damage, moisture, and chemical exposure.
2. What are the main types of cables used for communication and networking?
For communication and networking, cables are designed to transmit data signals with high fidelity. The three main types are:
- Twisted Pair Cable: Consists of pairs of insulated copper wires twisted together to reduce electromagnetic interference. It is commonly used for telephone lines and Ethernet networks.
- Coaxial Cable: Features a central conductor surrounded by an insulating layer, a metallic shield, and an outer jacket. It's used for cable television, internet, and radio transmissions due to its excellent shielding against noise.
- Optical Fibre Cable: Transmits data as pulses of light through thin strands of glass or plastic. It offers extremely high bandwidth and immunity to electrical interference, making it ideal for long-distance communication and high-speed internet.
3. What are the different types of cables used in a computer?
Computer systems use two main categories of cables for their operation: data cables and power cables.
- Power Cables: These supply electrical power from an outlet to the computer's power supply unit (PSU) or charge a laptop's battery. An example is the standard power cord with a three-prong plug.
- Data Cables: These transmit data between computer components or between the computer and external devices. Common examples include HDMI, VGA, and DVI cables for video display, and USB cables for connecting peripherals like keyboards, mice, and external drives.
4. Why is copper the most common material for the conductor in electrical cables?
Copper is the preferred material for conductors in most electrical cables due to its excellent combination of properties. It is one of the best electrical conductors, second only to silver, but is significantly more affordable and abundant. Furthermore, copper is highly ductile, meaning it can be easily drawn into thin wires without breaking. It also has high tensile strength and good resistance to corrosion, ensuring the cable's reliability and longevity.
5. How does an optical fibre cable transmit data with minimal energy loss?
An optical fibre cable transmits data using light signals with very little energy loss by leveraging a physics principle called total internal reflection. The cable's core is made of a transparent material (like glass or plastic) with a high refractive index, and it is surrounded by a layer called cladding, which has a lower refractive index. As light travels down the core, it strikes the core-cladding boundary at a shallow angle and is completely reflected back into the core, rather than escaping. This process repeats along the length of the cable, effectively trapping the light signal and guiding it to its destination with minimal signal degradation.
6. What is the key difference between a coaxial cable and a twisted pair cable?
The key difference lies in their structure and how they protect against interference. A coaxial cable has a concentric design with a central conductor surrounded by a metallic shield, which provides excellent protection against external electromagnetic interference (EMI). This makes it suitable for high-frequency signals like those in television. In contrast, a twisted pair cable consists of two insulated wires twisted around each other. The twisting itself cancels out interference from external sources and from adjacent pairs (crosstalk), making it a cost-effective solution for Ethernet and telephone networks.
7. What is the purpose of using different colour codes for wires inside a cable?
Colour coding for wires inside an electrical cable is a critical safety and functional standard. The different colours help electricians and technicians easily identify the purpose of each wire, ensuring correct and safe installation. For AC power circuits in India, the typical convention is:
- Red: Phase wire (live).
- Black: Neutral wire (completes the circuit).
- Green: Ground or Earth wire (safety wire to prevent shock).
Adhering to this standard prevents wiring errors that could lead to equipment damage, short circuits, or fatal electric shocks.
