Fuse in Electrical Circuit | Rewireable Fuse | Cartridge Fuse [2023]

In this blog, we discuss the Fuse in Electrical Circuit. Welcome to Poly Notes Hub, Your One-Stop Solution for Diploma Engineering Notes Syllabus-Wise.

What is Fuse ?

A fuse is a safety tool used to protect from damage to electrical circuits and the equipment they are linked to. Usually, a short, thin metal strip or wire is put into the circuit. A fuse’s main function is to open the circuit when too much current passes through it.

Purpose of Fuse in Electrical Circuit

Below, we listed some important purposes of fuse in electrical circuit

• To protect against damage from overcurrent and electrical circuit protection.
• To guarantee the security of electrical apparatus and systems.
• To cut off the electricity when the current goes above acceptable limits.

How Does Fuse Works?

The operation of a fuse is based on the principle of overcurrent protection. It’s important to understand that different devices and circuits have specific current requirements. When the current exceeds this requirement due to a short circuit or an overload, the fuse reacts.

The Principle of Overcurrent Protection

When overcurrent occurs, the fuse’s metal element quickly melts, creating a gap in the circuit. This gap interrupts the flow of electricity, effectively shutting down the circuit and preventing any potential damage. In essence, the fuse sacrifices itself to protect the rest of the circuit.

Types of Fuses

There are various kind of fuses that are used in electrical circuit. But, the most common type fuses are

Rewireable Fuse

These fuses consist of a wire or strip of a specific material that melts when excessive current flows through it. They are manually replaceable by rewiring with a new fuse wire.

Construction

A rewireable fuse, also known as a kit-kat fuse, consists of a base, a fuse carrier, and a fuse wire. The base is typically made of porcelain or a similar insulating material. The fuse carrier is a metal component that holds the fuse wire in place. The fuse wire is usually a thin, easily meltable wire, typically made of an alloy with a low melting point.

Working Principle

• In a rewireable fuse, the fuse wire is placed in the fuse carrier and connected to the electrical circuit.
• When the current in the circuit exceeds the rated capacity of the fuse wire, it begins to heat up due to the increased resistance.
• Once the fuse wire reaches its melting point, it melts and breaks the electrical connection.
• This interruption of the circuit prevents the flow of excess current, protecting the circuit and connected devices from damage or overheating.

Applications

• Used in Residential Wiring
• Used in small industrial electric connections.

Cartridge Fuse

These fuses come in two main types, High Rupture Capacity (HRC) and Low Rupture Capacity (LRC).

HRC Fuse

An HRC (High Rupture Capacity) fuse is a type of electrical fuse that is designed to provide a high level of protection in electrical circuits, especially in applications where there is a risk of high fault currents. HRC fuses are commonly used in industrial and commercial settings to safeguard electrical equipment and systems.

Characteristics of HRC Fuse

1. High Breaking Capacity: HRC fuses are engineered to handle and interrupt high fault currents without damage. This is essential in industrial environments where fault currents can be substantial.
2. Time-Delay: HRC fuses often have a time-delay characteristic. This means they can tolerate temporary current surges that might occur during the startup of motors or the operation of certain equipment. They do not blow immediately when there is a brief overcurrent, which helps prevent nuisance tripping.

Applications of HRC Fuse

1. Used in Industrial Machinery
2. In Power Distribution
3. Used in Electrical Panels

LRC Fuse

LRC stands for “Low Rupture Capacity.” An LRC fuse is a type of electrical fuse designed for applications with relatively lower fault currents, typically found in residential and light commercial electrical systems. LRC fuses are used to protect circuits and equipment in these settings.

Characteristics of LRC Fuse

1. Lower Fault Currents: LRC fuses are suitable for circuits where the potential fault currents are relatively low compared to industrial settings. They are commonly used in homes, small businesses, and other applications where the electrical loads are not as heavy.
2. Quick Acting: LRC fuses often have quick-acting characteristics. This means they blow or open quickly when there is an overcurrent or short circuit, providing rapid protection to prevent damage to wiring and connected devices.

Applications of LRC Fuse

1. Used in Residential Applications
2. Used in Automotive Circuits
3. Also in Lighting Systems

Conclusion | Diploma Engineering Notes | Poly Notes Hub

In this note, we are discussing the fuse in electrical circuit. Different types of fuse in electrical circuit that are used in our residential applications. Our Poly Notes Hub provides syllabus-wise notes for polytechnic or diploma engineering students of streams like Electrical Engineering, Electronics Engineering, Electrical and electronics Engineering, Electronics & Instrumentation Engineering, and Computer Science & Technology. Our website is updating day by day so keep in touch with us for new and syllabus-wise notes and topic which helps you all to do any task regarding diploma engineering.