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When the lights go off all of a sudden, what do we check at first?
It is the fuse box. Because if anything goes wrong with our electric supply it is our fuse that blows off. The fuse protects our homes.
What is a Fuse?
A fuse is a device used to protect electrical circuits from excessive current flow. It is designed to break the circuit and interrupt the flow of electricity if the current exceeds a certain level, thereby preventing damage to the circuit or electrical appliances and reducing the risk of fire.
Fuses consist of a thin wire or strip of metal that is designed to melt when the current passing through it exceeds a predetermined value. When the current reaches a critical point, the wire heats up and eventually melts, creating an open circuit and stopping the flow of electricity.
The main purpose of a fuse is to protect electrical equipment and wiring from overloading or short circuits. If too much current passes through a circuit, it can generate excessive heat, leading to damage or even fire. By interrupting the current flow, fuses help prevent such hazards by sacrificing themselves and breaking the circuit.
Fuses are commonly used in various applications, including residential and commercial electrical systems, automobiles, industrial machinery, and electronic devices. They are often housed in a protective fuse holder or fuse box, which makes it easier to replace them when they blow due to excessive current.
What is Fuse Link?
A fuse link, also known as a fusible link, is a type of electrical protection device that serves a similar function to a fuse. It is designed to protect electrical circuits from excessive current and prevent damage to the circuit or connected devices.
Unlike a traditional fuse, which consists of a replaceable element, a fuse link is a non-replaceable component. It is typically a short length of wire or a strip of alloy that is directly integrated into the circuit. The fuse link is selected based on its current-carrying capacity and is designed to melt or break when the current exceeds a predetermined value.
When the current flowing through a circuit exceeds the rating of the fuse link, it heats up rapidly and reaches a point where it melts or breaks. This action interrupts the circuit and stops the flow of electricity, protecting the circuit and connected devices from damage.
Fuse links are commonly used in applications where a replaceable fuse may not be practical or accessible. They are often found in high-current systems such as automotive wiring, heavy machinery, power distribution systems, and industrial equipment. In the event that a fuse link is blown, it typically requires replacing the entire link rather than simply replacing a fuse element.
It's important to note that the specific design and characteristics of fuse links may vary depending on the application and industry standards.
What is Earth Wire in a Plug?
The earth wire, also known as the grounding wire or ground connection, is an essential component of a plug and electrical system. It serves as a safety measure to protect against electrical shock and prevent damage to electrical appliances or devices.
The earth wire is typically represented by the green and yellow-colored wire in many electrical systems, although the specific color coding may vary in different regions. It is connected to the metal casing or chassis of an electrical device or appliance and provides a direct path for electrical current to flow into the ground.
The purpose of the earth wire is to provide a low resistance path for electrical current to follow in the event of a fault or malfunction that causes the metal casing or chassis of an appliance to become live or carry an electric charge. If a fault occurs, such as a short circuit or insulation failure, and the metal casing becomes energized, the earth wire provides a pathway for the current to flow directly into the ground, bypassing the user or any conductive surfaces.
By providing this alternate path, the earth wire ensures that any potentially dangerous electrical current is safely diverted away from people and objects, minimizing the risk of electric shock. This protective measure is particularly important in situations where there is a potential for the metal casing to become live, such as when an appliance's internal wiring becomes exposed or damaged.
In a properly grounded electrical system, the earth wire is connected to a grounding electrode, such as a metal rod driven into the earth or a metal water pipe. This connection helps maintain a stable reference voltage and dissipates any electrical charges safely into the ground.
It is important to note that the earth wire is only one component of a comprehensive electrical safety system. It works in conjunction with other safety measures, such as fuses or circuit breakers, insulation, and proper wiring practices, to ensure electrical safety in residential, commercial, and industrial settings.
Let's see how the fuse works? Fuse wires are made up of tin lead alloy. They usually have a low melting point with a proper rating and thickness. Fuses are usually connected in series with the live wire to complete th circuit. A fuse operates on the principle of the heating effect of electricity. When excess current flows in the circuit, it generates heat that melts the fuse wire and breaks the circuit.
Apart from fuses earthing also protects our homes. Look at the different colored wires that are located near your main meter box. Generally the live wire is red in color, the neutral wire is black in color and the earth wire is green or yellow green in color. The heating circuits which require large current and voltage have three wires instead of two. In all switches there are the same set of wires. The wire other than the live and the neutral wires is known as the earth wire. Generally it is covered by green or yellow green color insulation.
Now let's learn what is called an earth wire? The earthing of electrical equipment is done by connecting it to an earth grid or an electrode. The earthwire prevents electric shocks if there is any leakage of electric current in the circuit. Any leaking current goes to the ground through the earth wire. Many electrical appliances have metal cases, if the live wire of an appliance touches the metal casing by chance, you will get a shock. However if the earth terminal is connected to the metal casing then the current goes through the earth wire to the ground and you don't get a shock. In case of a fault involving the appliance the live part of the equipment touches the metal casing and gets connected to the minimum resistance of the earth path. The earth wire has very low resistance so when the earth wire and live wire are joined, a strong current surges through the earth wire. The heat of the current melts the fuse and the circuit disconnects from the power source. This reduces further damage to the equipment. The leaked current flows to the earth through the earth wire.
Now another question arises how does earthing protect human beings? If proper earthing is done, when a person touches an appliance with an electrical fault, he will not get an electric shock because his body and the equipment's body will be at the same potential thus the electric current doesn't flow through human body.
