Difference Between Fuse and MCB: A Comprehensive Guide

Difference Between Fuse and MCB

Difference Between Fuse and MCB – Fuse and MCB devices are employed as circuit protection devices to protect any equipment from damage brought on by short circuits. The use of these tools does not reduce the probability that a defect would occur. nonetheless, can assist us in avoiding the unfavorable effects of electrical faults. This article discusses the distinctions between fuses and MCBs as well as the benefits of each over the other.

The Linquip is an excellent resource for learning about fuses and MCBs. Whatever the case may be, we can aid you in identifying the most appropriate of these electrical devices. To ensure you can choose one that matches your demands, Linquip offers a broad variety of Circuit Breaker Products, as well as  Electrical Fuse Products.

On Linquip’s website, a comprehensive catalog of electrical components is available to all OEM fleets. Vendors for Linquip can assist you with this. For more information on where to look for a variety of service providers who consistently produce high-quality goods, please get in touch with Circuit Breaker and Electrical Fuse Experts. If you want to find out how much a fuse or MCB will cost, the Linquip platform offers a free quotation request service from various Circuit Breaker and Electrical Fuse Suppliers and Companies.

Electrical Fuse

What Is An Electrical Fuse and How Does It Work?

Fuses are electrical devices that are inserted between the two positive power terminals to deliver electricity to an electrical device. There is only one wire component, and if something goes wrong, it will easily melt away. In order to turn off energy to the equipment and prevent harm, the fuse wire should preferably melt. This happens when the power supply is larger than what the device requires. The fuse will obviously allow regular current or power flow via the cable up until an overload, also known as a high power supply, or current or power surge, happens. Therefore, fuses are designed precisely for the device and with its power requirements in mind. Nevertheless, they are created in the standard current ratings of 3 A, 5 A, and 13 A. A device capable of handling greater current than it requires should have a fuse installed. For instance, a 5 A fuse should be used if a device consumes 3 A of current. The fuse will blow at 5A current as opposed to 3A current, providing better protection.

Difference Between Fuse and MCB
Electrical Fuses (Reference: voyten.com)

A covering made of glass, ceramic, or metal protects the tiny wire. The setup is then placed in a building. A central fuse can protect the entire house. In such a case, it is installed in a central fuse box from which all of the house’s electrical wire emerges to power the home.

Once a fuse blows, it cannot be used again since the wire allowing current to pass through it has melted and broken. It will have to be changed. It is necessary to replace a fuse with a rating appropriate for the device and the required amount of electricity; otherwise, overheating will result from replacing it with a fuse that is higher rated than what the manufacturer intended or designed. The result might be fires.

Different Types of Fuses

Fuses were invented by “Thomas Alva Edison,” but there are now many other types of fuses available on the market. Fuse can be divided into two main types:

  • DC Fuses: DC fuses are larger in size. Since the DC supply has a constant value above 0V, it is difficult to forget to turn off the circuit, and there is a potential that melted wires could spark an electric arc. To combat this, electrodes are positioned farther apart, which causes the size of DC fuses to grow.
  • AC Fuses: AC fuses are smaller in size. They oscillated 50-60 times per second from minimum to maximum. Therefore, there is no possibility of an arc between the melted wires. Since they are little, they can be packaged.

Low voltage fuses and high voltage fuses are the additional two categories for AC fuses.

Difference Between Fuse and MCB
Classification of Electrical Fuses (Reference: circuitdigest.com)

The fuse speed is the amount of time it takes for a specific kind of fuse to blow. The three primary fuse speeds are as follows:

Ultra-rapid fuses: They are frequently employed in sensitive circuitry and transistors to prevent short circuits, reacting almost instantly. These fuses are additionally referred to as Very Fast Acting, Super Rapid, and High-Speed fuses.

Fast acting fuses: They are a more general-purpose fuse that is generally utilized with cabling and sturdier components. They are also referred to as F-Type or Fast Blow fuses.

Slow acting fuses: They have a delay mechanism that permits small, lower power electrical surges to pass through the circuit without blowing the fuse. They are often referred to as Time Delay or Slow Blow fuses. A greater performance delay mechanism is present in Dual Element Fuses.

Miniature Circuit Breaker (MCB)

What Is A Miniature Circuit Breaker?

Have you ever wondered what would occur to your household appliances, such as your fan, washing machine, oven, refrigerator, and so many others, in the event of a short circuit or an overflow of current? If the correct circuit breakers are not installed in the equipment, they burn and lead to fire disasters. A safety item having an electro-mechanical action mechanism is a miniature circuit breaker (MCB).

When the circuit is under too much current, an automatic switch known as an MCB opens. It may be closed once again without any manual replacement. In the case of a fuse, depending on the kind of the MCB, it must be changed or rewired after it has been activated. Fuse is hence referred to as one of the sacrificial devices. This is the main reason MCBs are employed in place of fuses in the majority of circuits. Additionally, the switches in the MCB immediately shut off whenever there is a failure in the circuit, making it simple to identify the problem with the device. It immediately recovers the supply and is generally safe to handle MCB. miniature circuit breakers are inexpensive to maintain and can be rapidly reset. MCBs protect against overload current and solenoid short circuit current using a bi-metal respective concept. 

Difference Between Fuse and MCB
Four Pole Miniature Circuit Breaker (MCB)  (Reference: amazon.com)

Working Principle of MCB

The image below depicts a typical working real-time MCB.

Difference Between Fuse and MCB
Structural Components of the MCB (Reference: byjus.com)

The following are the components of the MCB:

  1. Latch
  2. Solenoid
  3. Switch
  4. Plunger
  5. Incoming Terminal
  6. Arc Chutes Holder
  7. Arc Chutes
  8. Dynamic Contact
  9. Fixed Contact
  10. Din Rail Holder
  11. Outgoing Terminal
  12. Bi-metallic Strip Carrier
  13. Bi-metallic Strip

The bimetallic strip heats up and bends when the miniature circuit breaker receives a current overflow. A latch is released when the bimetallic strip deflects. The latch interrupts the circuit’s current flow, turning off the MCB. This procedure aids in protecting the gadgets or equipment from the dangers of overload or overcurrent. MCB must manually be turned ON in order to restart the current flow.

Difference Between Fuse and MCB
Working Principle of  MCB (Reference: byjus.com)

A short circuit causes the current to surge rapidly and unexpectedly, resulting in the electromechanical displacement of the plunger associated with a solenoid. When the plunger strikes the trip lever, the circuit breaker contacts open, releasing the latch mechanism.

An MCB is a straightforward, simple-to-use, and maintenance-free device. It is simple to replace an MCB. The trip unit, which powers the MCB (Miniature Circuit Breaker), is an essential component. The electromagnet in the MCB circuit protects against short-circuit current, and the bi-metal in the circuit prevents overload current.

Different Types of MCB

The type of MCB that must be utilized for certain appliances or equipment is determined by the MCB trip curve. The six categories of MCBs are as follows:

  • A Type MCB trips the circuit when the current reaches 2-3 times the actual current rating. Because A type MCB is extremely sensitive to a short circuit, we can use it to make semiconductors.
  • B Type MCB trips the circuit when the current reaches 3-5 times the current flow and is used in cable protection.
  • C Type MCB trips the circuit when the current reaches 5-10 times the actual current flow and is utilized in both home and commercial appliances such as transformers, fluorescent lighting circuits, and IT equipment such as personal servers, computers and printers.
  • D Type MCB trips the circuit when the current reaches 10-20 times the current flow and has a high resistance. Its applications include motors.
  • K Type MCB can resist up to 8-12 times the current flow and are used in heavy-duty load devices such as winding motors, compressors and X-ray machines.

What Is the Difference Between Fuse and MCB?

The primary distinction between a fuse and a miniature circuit breaker is that a circuit breaker mechanically disconnects the connection whenever the power load exceeds the supply. By doing this, connected device fires and other problems are prevented. A fuse, on the other hand, prevents a certain device from being ruined if the incoming current exceeds the required level. 

Below are some further differences between these electrical devices.

  • Reusability: If the incoming current is larger than what the device requires, a fuse will blow, but it cannot be utilized again after that. On the other hand, a circuit breaker works by mechanically tripping and cutting the connection. It may be used for several purposes and is simply turned back on.
  • Principle of Operation: A circuit breaker electromagnetically breaks the connection, but a fuse employs conducting materials whose electrical and thermal qualities hurt when the current surpasses the required amount.
  • Response Time: Circuit breakers react in between 0.02 and 0.05 seconds, whereas fuses react in 0.002 seconds.
  • Operating Mode: A circuit breaker operates mechanically and manually, whereas a fuse operates automatically but mechanically because it must be replaced.
  • Switching Action: A fuse cannot be used on ON/OFF switches, although a circuit breaker may.
  • Protection: Unlike fuses, which only offer protection against power overloads, circuit breakers safeguard buildings and equipment against both short-circuiting and power overloads. This is an important consideration when choosing between a fuse and a circuit breaker.
  • Breaking Capacity: Circuit breakers have a higher breaking capacity than fuses.
  • Characteristic Curve: The aging effect causes a fuse’s characteristic curve to shift. whereas the circuit breaker’s characteristic curve does not change.
  • Application: Instead of just one or two electronic devices, the entire home is protected by circuit breakers. Fuses only cover certain devices, not the entire house or apartment. This is especially important when deciding between a fuse box and a circuit breaker.
  • Version: Electrical fuses are only available in single pole versions, but circuit breakers come in single and multiple versions.
  • Cost Component: Fuse prices are lower than those of circuit breakers. A fuse is actually far less expensive than a circuit breaker. A factor to take into account while choosing between a fuse and a circuit breaker is cost.

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