What is Fuse? Type of fuse
A fuse is a very important protection device in the electrical field. In this article of Fuse, the fuse has been explained in detail. In which definition of fuse, types of fuse, advantages, and disadvantages of fuse, how a fuse works, and what is the main use of fuse? You will find answers to all these questions here.
What is Fuse?
A fuse is a protection device for equipment used in electrical and electronics equipment. A fuse is used to protect electrical circuits and electrical equipment.
Electricity was a great invention. Electricity has a hand in the pace at which the world is progressing today but we should not be careless in using it.
Malfunction can occur in any electrical circuit or equipment at any time. At such times a fuse forms a protective shield for that circuit or device. Or if there is an event of overload or short circuit in the electrical circuit, then at such time the fuse gives protection to the circuit.
Fuse helps to disconnect power to the circuit at the time of a fault or fault in the circuit. When a circuit or equipment is short-circuited or overloaded, the fuse cuts off the power supply. Isolates the power supply from the circuit. Due to this, we can avoid a big accident.
Fuse Definition
In an electrical system, an electric current travels through a wire. This wire breaks or melts when more current is passed than the dissipated current and stops the power supply within the circuit. It is called a Fuse.
Description of Fuse Rating
In any fuse, the rating of Ampere, Voltage, Type, Size, and KA is written. Its meaning is that this fuse can handle so much voltage and ampere.
For example, you can see written on top of a fuse
Voltage – 600 V
Ampere – 100 A
Type – HN
Size - 00
KA – 90 KA
Here the meaning of 600 V AC is that this fuse can run up to 600 AC volt. If more voltage is passed than this, the fuse will blow.
In the same way, this fuse can pass electric current up to 100 amperes. If more current is passed then this fuse will blow.
Which type of fuse is there, it is also written on the top of the fuse. Well, there are many types of fuses available. We should choose our type according to our needs.
Fuse is available in different sizes. The size of the fuse will be fitted in the fuse base. That is why the size should be taken care of before taking the fuse.
What is the KA rating in the fuse?
If there is a fault or short circuit in the electrical circuit, then a large current is transmitted.
KA Rating is the ability to tolerate a high current that is transmitted during a short circuit. In a way, this is the breaking capacity of the fuse.
If a fuse has a rating of 90 KA. During a short circuit, 90KA of current flows through the circuit, then it will break the circuit safely.
How to select a fuse for a house?
We have seen letters in our homes that there is a fuse near the main switch. Somewhere there is a separate fuse for each room.
Fuses are used a lot in industries. A fuse is used to protect every electrical appliance.
The size and capacity of the fuse vary. The fuse is fitted according to the capacity of the electrical load.
As an example
The capacity of the fuse is in ampere. The electrical load of our house is 7 amperes. This is the maximum load. So a 10-ampere fuse should be installed in our house.
That is, the capacity of the fuse should be more than the electrical load that is going on.
A formula can be used to select the fuse for the home.
Fuse Capacity = Watt/Volt * 1.25
Fuse Capacity - Fuse Rating
Watt - Power
Volt – Electric pressure
Remember – If the capacity of the fuse is less than the current flowing in the circuit, then the fuse will blow immediately. And if the rating of the fuse is too high with the current flowing in the circuit, then the fuse will not be able to protect the circuit. That is why special care should be taken in the selection of fuses.
How does a fuse work? Function of fuse
The fuse consists of a metal wire. This wire is made of copper, silver, aluminum, antimony, tin, and lead. The wire inside the fuse is according to its ampere capacity.
The distance is more, more current is transmitted through that metal wire. For example, the melting point of copper is 2000, and the melting point of aluminum is 1243. Here, if both the metal wires of the same size are taken, then more current will spread than the copper wire.
There is a wire inside depending on the current carrying capacity of the fuse. If current flows in any conductor, then the temperature increases. The wire inside the fuse allows the current to flow according to its potential. If it goes above its capacity, then this wire breaks.
As an example
The capacity of a fuse is 10A. This means the capacity of the wire inside it to dissipate 10-ampere current. If more than 10 amperes of current is passed, the wire inside the fuse will heat up.
Due to the increase in ampere temperature, the wire will break and melt. Which will cut the power of the circuit and our equipment will be saved from great damage.
Types of Fuse
There are two main types of the fuse.
AC Fuse – AC Fuse is used where AC is supplied.
DC Fuse – DC Fuse is used where there is DC supply.
There are two types of fuse based on voltage
HV Fuse – High Voltage
HV Fuse – HV means high voltage. HV fuse means fuse used in high voltage. Like the fuse used in 11KV, 22KV, 33KV is called HV or HT fuse. This fuse is more commonly used in the current transformer (CT) Potential Transformer (PT) unit of HT breaker.
DO Fuse – Drop Out Fuse
DO Fuse (Drop out Fuse) is used in the HT yard. HT yard is there in every company. Where does the main supply line come from? DO fuses are installed on both the outside and inside of the HT yard.
These fuses are made for high voltage. There is a special way to put it. And there is an insulated road to put it. Which is called DO Rod.
LV Fuse – Low Voltage Fuse
LV Fuse – The meaning law of LV is voltage. LV fuse means fuse used for low voltage. By the way, the voltage rating is written on the fuse.
The fuses used in our house are low voltage. The power supply in our house is 230 volt AC. Here the fuse low caused by the decrease in the value of voltage is called voltage fuse.
By the way, the use of low voltage fuse is very much in industries too. In electronic equipment, fuses of capacities ranging from 0.5 amp to 800 amp are used in industries control.
There are two types of fuses based on the design of the fuse.
Rewireable Fuse – Semi Enclosed Fuse
The name of the Rewireable Fuse itself suggests the work. We can reuse this fuse. This fuse has a base in which the fuse is mounted. The wire is placed over the fuse.
If an overload or short circuit occurs in the electrical equipment and circuit, the fuse opens. That means the wire inside the fuse is broken. In a rewireable fuse, we can use the fuse by tying the wire again. That is, the fuse which we use again after being opened is called a semi-enclosed ie a rewireable fuse.
The fuses used in our home are Rewireable fuses only. Which we call kit kat fuse. This type of fuse is used in low current capacity.
Advantages of Rewireable Fuse
1) This type of fuse is cheap in price.
2) The same fuse can be used again by inserting an element.
3) It takes very little time and cost to replace the fuse element.
4) The construction of this type of fuse is simple anyone can manage it.
5) The operation of this fuse can be done easily even when the power supply is on.
Non-advantage of Rewireable Fuse
1) The size of the wire is not fixed while re-tying the fuse. Sometimes large size wires are used. Due to which the risk increases.
2) Due to the low breaking capacity of the fuse, this fuse is used for law capacity.
Cartridge Fuse – Total Enclosed Fuse
The body of this type of fuse is closed. We can't see the wire inside the fuse. That is, even air does not enter it. The body of the cartridge fuse is made of masonry. Chemical powder or silicone sand would have been used inside the fuse.
Cartridge fuses cannot be reused. That is, if these fuses blow for some reason, they are opened, then they cannot be used again. We have to change the fuse. In place of the old fuse, another new fuse has to be installed.
Cartridge fuses are of two types
LRC – Low Rupturing capacity
This type of fuse has less rupturing capacity. LRC fuses are available in capacities from 0.25 mA to 32 A. Key Ampere Capacity
HRC Fuse – High Rupturing Capacity
The full form of HRC Fuse is a High rupturing Capacity. That is, this fuse has the ability to carry current for a long time. Fuse with high resistance to breakage of wire.
In electrical there are HRC fuses of different body compositions. It consists of fuses used in both control circuits and power circuits. Most of the HRC fuses are used in industries.
The starter that supplies power to the motor has SFU. In this switch fuse unit, only HRC (High Rupturing Capacity) fuse is used.
HRC Fuses
When an electric motor is started, it takes a lot of amperes. Fuse's ability to withstand this current for a few seconds
should be in If the fuse is opened by the starting kick of the motor, then we will not be able to use the fuse.
The corrective stick of the HRC fuse is high. This fuse has the ability to bear a high current for some time. That is why it is called the fuse of HRC (High Rupturing Capacity).
Benefits of HRC Fuse
1) This type of fuse is the most reliable fuse.
2) This type of fuse does not require maintenance. The second is applied as soon as it is opened.
3) A fuse puller is used to change this which is very easy.
4) This type of fuse has an opening indication. Available in capacities ranging from 5 – 2 amps to 800 amps.
Wire size inside HRC fuse and its current carrying capacity
Copper Wire Size Fuse Current Rating Copper Wire Size Fuse Current Rating
- 0.15 sq.mm 3 ampere
- 0.20 sq.mm 5 ampere
- 0.35 sq.mm 10 ampere
- 0.50 sq.mm 15 ampere
- 0.60 sq.mm 20 ampere
- 0.75 sq.mm 25 ampere
- 0.85 sq.mm 30 ampere
- 1.25 sq.mm 45 ampere
- 1.53 sq.mm 60 ampere
- 1.80 sq.mm 80 ampere
- 2.00 sq.mm 100 ampere
What is SFU?
Electrical has SFU FULL Form – Switch Fuse Unit. That is, SFU is a unit made up of a switch and fuse. The size of SFU is in Ampere. It has a fuse base. The fuses are mounted in the fuse base of the SFU.
SFU – Switch Fuse Unit has a handle. This handle is used to switch on and off. SFU is used to provide a power supply to any device. SFU is 3 poles and 4 poles. 3 pole SFU is for three phases and 4 poles are for three-phase and neutral.
In any fault, the SFU's fuse gets opened. And you can avoid big losses. We can give power again by replacing the fuse that has been opened.
What metal is the fuse wire made of?
Fuse wire is used for silver, copper, aluminum, zinc, antimony, lead, and tin. The metal whose melting point is high, the capacity of that metal wire to carry electric current is high.
What is the use of fuse? Uses of Fuse
Fuse is a protection device for electricity. Fuses are used to protect an electrical circuit and equipment. If more current flows in any circuit than the prescribed current, the fuse isolates the circuit from the power supply.
Works to provide protection in the event of an earth fault, short circuit, and overload in an electrical circuit.
Hope this will be helpful for you.
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