Electric fuse: You must know about it.

The least expensive method of protecting against too much current is a fuse. It was made by Edison in 1890. Numerous advancements have been made since the original simplistic model was created. 

 Today, low- to medium-voltage applications widely use various types of fuses. Where frequent operations are not necessary and the usage of a circuit breaker is not cost-effective, we can employ fuses. 

    The tiny fuse wire is typically enclosed in a safety sheath to reduce the risk of an arc burst if it burns out suddenly, as can happen in the event of a significant overcurrent. Small fuses have translucent sheaths that allow for visual inspection of the fusible element.

Table of Contents

• What is Fuse?
• Working Principle of Fuse
• What happens if the wrong fuse is installed?
• What does a blown fuse look like?
• What is the difference between Fuse and Circuit breaker?
• Challenges in Power Sector in Bangladesh

What is a fuse?

 "A fuse is a little piece of metal that is put into a circuit and melts when too much current passes through it, breaking the circuit."

"A fuse is a type of electrical safety device constructed from conductive strips that is intended to melt and cut off the circuit in the case of an excessive current." 

The fuse element is generally made of materials having

    1. Low melting point.

    2. High conductivity.

    3. Least deterioration due to oxidation.

Working Principle of fuse.

    The fuses are connected in series with the load that has to be protected in the circuit. This means that if the fuse blows, the circuit will be opened and the components won't receive any current. When the fuse is acting normally, the element doesn't overheat and maintains a temperature below its melting point. 

    The current flowing through the fuse exceeds its rated value whenever a short circuit or overload happens. The load (machine or equipment) is isolated as a result of the high current raising the temperature to the point where the fuse element melts and blows out. A fuse prevents damage from being done to the machinery and equipment as a result of an excessive current.

Fig: Blade type fuse(Ref.- fuse-box.info)

 

Read more: Why do fuses blow in car?

What happens if the wrong fuse is installed?

If we think from an electrical point of view, there are only two options in selecting the wrong fuse: either an overrated fuse or an underrated fuse. 

Overrated fuse: The worst-case scenario is to damage the equipment caused by an overcurrent or overload.

Underrated fuse: Other possibilities include the fuse blowing even though there is no electrical fault.

    Suppose you have a blender machine; inside it there is a fuse with a current-carrying capacity of 6A as a protective device. Whenever it is required to replace this fuse, if you place a fuse with a current capacity of more than 6A, then it is called an overrated fuse, and if it is less than 6A, then it will be an underrated fuse. Both are harmful for your blender machine. 

It is always best practice to replace a blown fuse with the same rated fuse.

In a house, what does a blown fuse look like?

It's very important to understand the appearance of a blown fuse before attempting to identify the source of the issue. Charring on the fuse itself is the most obvious indicator of a blown fuse, but there are other signs as well, such as the chance of partial or total house power outages. This is how a circuit breaker operates—it isolates the fault and prevents it from damaging other circuits. 

Let's look at eight potential reasons for blown fuses.

1. Overloaded Circuit
In our experience as expert electricians, the most frequent reason for a blown fuse is when anything consumes excessive power from the circuit. The most common causes of this include using too many plug-in appliances at once or utilizing too many lights. The most common cause of this kind of problem is an adapter with several outlets inserted into a socket.

2. Short Circuit or Ground Fault

To state it simply, a short circuit occurs when a current is directed along a direction it shouldn't. This can be caused by a lot of factors, including moisture, insects, and faulty wiring and accessories. As the name implies, a ground fault is a kind of short circuit in which the current is diverted to the earth or ground. 

3. Arc Issues
An arc fault may result from loose screws, corroded wiring, or issues with the actual circuit connections. These defects are the most typical reason for electrical fires in homes, making them potentially dangerous. 

Study more: Bad Circuit breaker: what you must know about it.

4. Circuit or Breaker Issues

The purpose of circuit breakers is to stop further electrical damage in the event that a fuse blows. However, if the breaker trips frequently, there may be an issue.

5. Damaged Electrical Outlets
Older electrical outlets are more likely to have damaged wiring or loose connections. If the plugs receive improper current, appliance fuses may blow.

6. Damaged Wiring

This problem can be difficult to detect because the wiring is hidden behind the walls. Even if a fuse has blown, you may not notice the condition of the wiring. 

7. Wrong Type of Fuse

Although all fuses appear to be the same, there are many distinct types and sizes available. Having the improper fuse can be dangerous and cause serious damage in your home. If you suspect there may be an erroneously sized fuse, keep away from the fuse box and consult a professional.

8. Moisture Buildup

If your home is damp or has suffered storm damage, moisture may have found its way into the wiring. This can lead to wire degradation, short circuits, and a variety of other difficulties.

What is the difference between a fuse and a circuit breaker?

Fuses and circuit breakers have very similar functions: they both interrupt electrical circuits in the case of a current overload or short circuit. However, there is one important difference. Circuit breakers are switches, and much like any other switch, they can be reset after being flipped. 

Fig: Fuse Vs Circuit breaker

Most fuses, however, can only be used one time. Once blown, they must be replaced. Fuses are cost-effective and can be replaced very quickly and easily, requiring minimal downtime. It is essential that you use a fully compatible model with the appropriate current rating for your device. This value represents the amount of current that the fuse will accept before blowing.