So, here are some of the applications of fuses:
- Motors and transformers
- Digital cameras
- Laptops
- Printers
- DVD players
- Instrument transformers
- Cell phones
- Air-conditioners
- Scanners
- Game systems
- Power systems
- Power transformers
- Light bulb
What are the disadvantages of using fuses?
they tend to blow at periods of high stress, which is usually inconvenient. If used correctly the main disadvantages of fuses are disconnect time and the fact they cannot differentiate between an overload condition and an earth fault.
What is a fuse and what is it used for?
What is a Fuse? A fuse is an electric / electronic or mechanical device, which is used to protect circuits from over current, overload and make sure the protection of the circuit. Electric fuse was invented by Thomas Alva Edison in 1890.
What is often used instead of a fuse?
Relays are generally used to switch smaller currents in a control circuit and do not usually control power consuming devices except for small motors and Solenoids that draw low amps. Why use a relay instead of a fuse? Fuses limit current and protect against fire.
What are the most common types of fuses?
The 5 Different Types of Car Fuses
- Blade Fuses. One of the most common types of automotive fuses that you are likely to encounter is the blade fuse.
- Cartridge Fuses. Cartridge fuses are extremely popular for cars, and you will also find them in other areas, like the home.
- PAL Fuses. ...
- High-Current Fuses. ...
- Circuit Breaker. ...
What is fuse and its use?
In electronics and electrical engineering, a fuse is an electrical safety device that operates to provide overcurrent protection of an electrical circuit. Its essential component is a metal wire or strip that melts when too much current flows through it, thereby stopping or interrupting the current.
What are the five uses of fuse?
Why Use a Fuse?Safety. Overcurrent protective devices that have tripped are often reset without first investigating the cause of the fault. ... Cost-effective. ... High interrupting rating. ... Reliability. ... North American standards. ... Component protection. ... Extended protection. ... Selectivity.More items...•
What is the main function of fuse?
The primary use of an electric fuse is to protect electrical equipment from excessive current and to prevent short circuits or mismatched loads. Electrical fuses play the role of miniature circuit breakers. Apart from protecting equipment, they are also used as safety measures to prevent any safety hazards to humans.
What are the 3 types of fuses?
Classification of Fuses Fuses can be classified as “One Time Only Fuse”, “Resettable Fuse”, “Current limiting and non – current limiting fuses” based on the usage for different applications.
What is difference between fuse and circuit breaker?
One of the basic differences between a fuse and a circuit breaker is that fuse is a metal piece that melts when there is excess current due to overload, while a circuit breaker has an internal switch that gets tripped when there is excess current in the circuit from an overload or short circuit.
What are advantages of fuse?
Fuse is cheapest type of protection in an electrical circuit. Fuse needs zero maintenance. Operation of fuse is simple and no complexity is involved. Fuse has the ability to interrupt enormous short circuit current without producing noise, flame, gas or smoke.
What do fuses protect against?
A fuse protects a system or equipment from overload and short-circuit faults by cutting off the power to them. It achieves this by melting or vaporising of the fuse element so that there is no physical connection conductive path for the current flow through.
Which wire is used in fuse?
Electrical fuse Because of its high resistance and low melting, fuse wire is made of Sn (tin) and Pb (lead) alloy. The tin and lead alloy has a eutectic composition of 62 percent tin and 38 percent lead and melts at 183 degrees Celsius.
What are the uses of fuse Class 10?
A fuse is used in a circuit to avoid overloading or short circuiting. When a current higher than the rating of the fuse flows through it, the fuse wire gets heated and melts. This breaks the circuit and protects the appliances from getting damaged.
What are the uses of fuse Class 7?
A fuse is a safety device which limits current in circuit as a result it prevents damages to electrical circuits and possible fires. Fuses used in electrical appliances. In order to make a battery the negative terminal of one cell is connected to the positive terminal of the other cell.
What is the use of fuse Class 6?
A fuse is a safety device made up of a conducting material having low melting point. It works on the principle of heating effect of current.
What is the use of electric fuse Class 7?
Answer: Solution: Electric fuse is a safety device used to limit the current in an electric circuit which melts and breaks the circuit whenever there is an excess flow of current through the circuit.
What is a fuse?
In electronics and electrical engineering, a fuse is an electrical safety device that operates to provide overcurrent protection of an electrical circuit. Its essential component is a metal wire or strip that melts when too much current flows through it, thereby stopping or interrupting the current. It is a sacrificial device; once ...
Why are fused devices used?
Fuses have been used as essential safety devices from the early days of electrical engineering. Today there are thousands of different fuse designs which have specific current and voltage ratings, breaking capacity, and response times, depending on the application.
How does voltage drop affect a fuse?
The manufacturer may specify the voltage drop across the fuse at rated current. There is a direct relationship between a fuse's cold resistance and its voltage drop value. Once current is applied, resistance and voltage drop of a fuse will constantly grow with the rise of its operating temperature until the fuse finally reaches thermal equilibrium. The voltage drop should be taken into account, particularly when using a fuse in low-voltage applications. Voltage drop often is not significant in more traditional wire type fuses, but can be significant in other technologies such as resettable (PPTC) type fuses.
What are the different types of fuses?
Automotive fuses can be classified into four distinct categories: 1 Blade fuses 2 Glass tube or Bosch type 3 Fusible links 4 Fuse limiters
What is a fuse in electrical?
A fuse consists of a metal strip or wire fuse element, of small cross-section compared to the circuit conductors, mounted between a pair of electrical terminals, and (usually) enclosed by a non-combustible housing . The fuse is arranged in series to carry all the current passing through the protected circuit.
How long does it take for a fuse to blow?
A standard fuse may require twice its rated current to open in one second, a fast-blow fuse may require twice its rated current to blow in 0.1 seconds, and a slow-blow fuse may require twice its rated current for tens of seconds to blow . Fuse selection depends on the load's characteristics.
What is a fuse element made of?
The fuse element is made of zinc, copper, silver, aluminum, or alloys among these or other various metals to provide stable and predictable characteristics. The fuse ideally would carry its rated current indefinitely, and melt quickly on a small excess. The element must not be damaged by minor harmless surges of current, and must not oxidize or change its behavior after possibly years of service.
Where are fuses used?
A good example of where fuses are used are in circuits for electrical motors. The motor protection overload will open when in the event of a short circuit or severe overload.
What is a fuse?
A fuse is a device built for safety and protection of a circuit. They are internally filled with a conductive strip that melts in the event of a excessive current passing through. A fuse is always fitted in series with the circuit/components that need protecting from overcurrent.
Who invented fuses?
Thomas Edison patented a type of fuse in 1890 as part of his electrical distribution system.
Why are switch fuses used in semiconductor devices?
They are used in Many semiconductor devices because semiconductor devices are damaged by over current very rapidly. There is another fuse which Is called a slow burn fuse, switch fuses do not respond rapidly to the over current event, but blow after several seconds of over current occurrence.
What is a general fuse?
A general Fuse consists of a low resistance metallic wire enclosed in a non combustible material. It is used to connect and install in series with a circuit and device which needs to be protected from short circuit and over current, otherwise, electrical appliance may be damaged in case of absence of the fuse and circuit breaker as they are unable to handle the excessive current according to their rating limits
How to Select Proper Rating Size of Fuse?
While selecting the proper fuse and its rated size for electrical appliances is based on different factors and environments. But the following basic formula shows how to choose the right size of fuse?
How many categories of fuses are there?
Fuses can be divided into two main categories according to the type of input supply voltage.
What is the carrying capacity of a fuse?
Current carrying capacity is the amount of current which a fuse can easily conduct without interrupting the circuit. Breaking capacity: The value of maximum current that can safely be interrupted by the Fuse is called Breaking Capacity and should be higher than the prospective short circuit current.
Why is the arc of a DC fuse so difficult to extinguish?
In a DC system , when the metallic wire melts because of the heat generated by the over current, then Arc is produced and it is very difficult to extinguish this arc because of DC constant value. So in order to minimize the fuse arcing, DC fuse are little bigger than an AC fuse which increases the distance between the electrodes to reduce the arc in the Fuse.
How does the speed of a fuse affect the response time?
The speed at which the fuse blows, depends on the amount of current flowing through its wire. The higher the current flowing through the wire, faster will be the response time.
What is the purpose of a fuse?
A fuse is probably the simplest electrical device, but its function is critical in protecting electrical circuits from damage. Fuses are found in every circuit in one form or another in various shapes, sizes, and ratings. In this article, we will learn how a fuse works and about ...
How does a fuse work?
The primary job of a fuse is to break the circuit if a current higher than desired is drawn by the circuit, thus preventing damage due to short circuits.
Why are cartridge fuses filled with oil?
Some variants of this fuse are encased in ceramic to withstand high temperatures. Fuses for high voltage applications are filled with sand or oil. This is to prevent arcing between the two ends of the fuse after it has blown. SMD variants of cartridge fuses also exist for direct PCB mounting.
What is a fuses blade?
These fuses are specifically designed for automotive systems that run up to 32V and occasionally 42V. They come in ‘blade’ form (a transparent plastic envelope with flat contacts) and are colour coded according to rated current. Some of these types are also used in other high-power circuits.
What is a quartz fuses?
The fuse is filled with quartz powder (and in the case of a liquid-filled HRC fuses, a non-conducting liquid like mineral oil) that acts as an arc extinguishing agent. These fuses are used for very high fault currents. Expulsion Fuses: These fuses are filled with chemicals like boric acid that produce gases on heating.
What is a fuse element made of?
The thickness and length of the resistive element determine the rated current. Fuse elements are made of zinc, copper, silver, aluminium or other alloys to provide predictable trip currents. The element must not oxidize or corrode over time.
What is a fuses self reset?
Like their name suggests, these fuses are self-resetting. They contain carbon black particles embedded in organic polymers. Normally, the carbon black makes the mixture conductive. When a large current flows, heat is generated which expands the organic polymer.
Small cartridge fuses
Cartridge fuses, which form a very important and certainly the most numerous group, may be designed for high voltage, low voltage, or miniature applications. For low voltage applications, the fuse-link, which is replaceable, is often fitted into a fuse holder that consists of a fuse carrier and a fuse base.
Expulsion fuses
The expulsion fuse, which belongs to the high voltage category, contains a mechanism to move the fuse link away from one of its contacts when the element melts and as a result, a long gap is introduced in the air in series with the fuse.
Automotive fuses
In recent years, the amount of electrical and electronic equipment installed in motor vehicles has increased greatly, resulting in more complex 12 V systems and load requirements ranging from 1000 W to in excess of 2000 W in highly appointed vehicles.
Through-hole fuses
Small fuses with radial leads, which seem appropriate for through-hole insertion in printed circuit boards, are actually often used in conjunction with appropriate sockets so that they can be easily replaced.
Resettable fuses
Properly known as a polymeric positive temperature coefficient fuse (often abbreviated PTC or PPTC), a resettable fuse is a solid-state, encapsulated component that greatly increases its resistance in response to a current overload, but gradually returns to its original condition when the flow of current is discontinued.
Surface-mount fuses
Because surface-mount fuses are difficult or impossible to replace after they have been soldered onto the board, they are often resettable. As consumer electronic products become smaller and more portable, printed-circuit-boards have become more densely populated, forcing fuses located on the board to become even smaller.
Blade-contact-type fuses
These are generally referred to as NH fuses, NH being an abbreviation of Niederspannungs Hochleitungs which is German for low-voltage high- breaking capacity.
How to identify fuses?
You can identify fuses by two letters according to your applications (more details later). For low voltage applications, we have gG and aM fuses.
Why do you put fuse wires in safety sheaths?
Additionally, you’ll find that manufacturers place fuse wires within a safety sheath to minimize the hazards of the wire burning up with violent force. When this happens, it creates an Electric arc blast. Usually, this occurs during severe overcurrents.
Why does a fuse have a melting point?
As current flows into the element, it creates a tiny voltage drop across the element (small enough not to affect the circuit downstream). This process dissipates some power as heat. Thus, increasing the resistive element’s temperature.
How much power can a high breaking capacity fuse limit?
The higher the breaking capacity, the stronger the fuse. Furthermore, high breaking capacity fuses can limit short circuits reaching up to 100 000 A RMS.
What happens when a fuse blows?
So, when the fuse opens (blows), it stops the flow of current through the components by opening the entire circuit. However, connecting the fuse in one branch of a parallel circuit won’t affect the flow of current in other branches.
Why is DC fuse bigger than AC fuse?
The DC fuse is different from the AC fuse when it comes to size. It’s bigger because of the constant values of direct current circuits. When the current rating goes past the maximum current limit, the metallic fuse wire melts and disconnects the rest of the circuit from the power supply. So, here are the different types of DC fuse:
What is circuit safety?
Circuit safety is the specialty of a fuse. A fuse is an electrical safety device. It has a conductive strip that melts and separates whenever there’s an overflow of current. It would help if you always connected a fuse in series with the electrical components—you want to protect.
What is a fuse label?
UL and CSA are the most common fuse certifications used in North America. The fuse label may provide information on the applicable AC or DC voltage, the maximum current rating and other information such as “interrupting rating”, “current limiting”, “time-delay” and “fast-acting”.
How to size a fuse?
When sizing the fuse, the most common calculation method is to multiply the continous load/feed current of a branch by 1.25, and using the closest rated fuse that is greater than your result. However, there are exceptions to this calculation method.
What is a time delay fuse?
Time-delay: A fuse in which the burnout action depends on the time it takes for the overcurrent heat to build up in the fuse and melt the fuse element. Fast-acting: A fuse that opens on overload and short-circuits very quickly.
What is the most important part of electrical wiring?
One of the most important aspects of electrical wiring of photovoltaic systems is fusing. Fuses provide integral protection against overcurrents that could otherwise damage your valuable PV equipment. Furthermore, using an incorrect fuse can be extremely hazardous!
What is a class T fuses?
Class T fuses can be used in applications that require fastacting protection, such as equipment containing variable speed drives, rectifiers , and other surge-sensitive components. Main switches containing Class T fuses may be used to provide protection to individual electric services and meter stacks.
Can AC rated fuses be used in DC circuits?
AC rated fuses SHOULD NOT be used in DC voltage circuits unless DC application ratings are provided by the fuse manufacturer. The characteristics and certification of the fuses are usually defined on the fuse label. UL and CSA are the most common fuse certifications used in North America.
Can a 600 VAC fuse be used on a DC disconnect?
We have observed that a very common mistake is to use a fuse that is rated for 600 VAC on a DC disconnect that is rated for 600 VDC. At first sight, the cable size, the current rating may seem correct, however, the voltage rating (a small description on the fuse) is even more important than the current rating in some circumstances. AC rated fuses SHOULD NOT be used in DC voltage circuits unless DC application ratings are provided by the fuse manufacturer.
Overview
Automotive fuses
Automotive fuses are used to protect the wiring and electrical equipment for vehicles. There are several different types of automotive fuses and their usage is dependent upon the specific application, voltage, and current demands of the electrical circuit. Automotive fuses can be mounted in fuse blocks, inline fuse holders, or fuse clips. Some automotive fuses are occasionally used in non-automotive electrical applications. Standards for automotive fuses are published by SAE …
History
Breguet recommended the use of reduced-section conductors to protect telegraph stations from lightning strikes; by melting, the smaller wires would protect apparatus and wiring inside the building. A variety of wire or foil fusible elements were in use to protect telegraph cables and lighting installations as early as 1864.
A fuse was patented by Thomas Edison in 1890 as part of his electric distribution system.
Construction
A fuse consists of a metal strip or wire fuse element, of small cross-section compared to the circuit conductors, mounted between a pair of electrical terminals, and (usually) enclosed by a non-combustible housing. The fuse is arranged in series to carry all the charge passing through the protected circuit. The resistance of the element generates heat due to the current flow. The size and construction of the element is (empirically) determined so that the heat produced for a nor…
Characteristics
A maximum current that the fuse can continuously conduct without interrupting the circuit.
The speed at which a fuse blows depends on how much current flows through it and the material of which the fuse is made. Manufacturers can provide a plot of current vs time, often plotted on logarithmic scales, to characterize the device and to allow comparison with the characteristics of protective devices upstream and downstream of the fuse.
Voltage drop
The manufacturer may specify the voltage drop across the fuse at rated current. There is a direct relationship between a fuse's cold resistance and its voltage drop value. Once current is applied, resistance and voltage drop of a fuse will constantly grow with the rise of its operating temperature until the fuse finally reaches thermal equilibrium. The voltage drop should be taken into account, particularly when using a fuse in low-voltage applications. Voltage drop often is no…
Temperature derating
Ambient temperature will change a fuse's operational parameters. A fuse rated for 1 A at 25 °C may conduct up to 10% or 20% more current at −40 °C and may open at 80% of its rated value at 100 °C. Operating values will vary with each fuse family and are provided in manufacturer data sheets.
Markings
Most fuses are marked on the body or end caps with markings that indicate their ratings. Surface-mount technology "chip type" fuses feature few or no markings, making identification very difficult.
Similar appearing fuses may have significantly different properties, identified by their markings. Fuse markings will generally convey the following information, either explicitly as text, or else implicit with the approval agency marking for a particular type:
What Is A Fuse?
Construction & Working of A Fuse
- A general Fuse consists of a low resistance metallic wire enclosed in a non combustible material. It is used to connect and install in series with a circuit and device which needs to be protected from short circuit and over current, otherwise, electrical appliance may be damaged in case of absence of the fuse and circuit breaker as they are unable to handle the excessive current accor…
How to Select Proper Rating Size of Fuse?
- While selecting the proper fuse and its rated size for electrical appliances is based on different factors and environments. But the following basic formula shows how to choose the right size of fuse? Fuse Rating = ( Power / Voltage ) x 1.25 For example, you have to find the right size of fuse for 10A two pin socket. (1000W / 230V ) x 1.25 = 5.4A In the above example, 1kW is the power ra…
Characteristics of A Fuse
- Different types of fuses can be categories on the following characteristics. 1. Current Rating & Current Carrying Capacity of Fuse 2. Voltage Rating of Fuse 3. Breaking Capacity of a Fuse 4. I2t Value of Fuse 5. Response Characteristic 6. Rated voltage of Fuse 7. Packaging Size Below is the brief explanation of the above categories.
Classification of Fuses
- Fuses can be classified as “One Time Only Fuse”, “Resettable Fuse”, “Current limiting and non – current limiting fuses” based on the usage for different applications. One time use fuses contain a metallic wire, which burns out, when an over current, over load or mismatched load connect event occurs, the user has to manually replace these fuses, switch fuses are cheap and widely used in …
Types of Fuses
- There are different types of fusesavailable in the market and they can be categories on the basis of Different aspects. Good to know: Fuses are used in AC as well as DC circuits. Click image to enlarge Fuses can be divided into two main categories according to the type of input supply voltage. 1. AC fuses 2. DC fuses There is a little difference between AC and DC fuses used in th…
Resettable Fuses
- Resettable fuse is a device, which can be used multiple times without replacing it. They open the circuit, when an over current event occurs and after some specific time they connect the circuit again. Polymeric positive temperature coefficient device (PPTC, commonly known as a resettable fuse, poly-switch or poly-fuse) is a passive electronic componentused to protect against short c…
Uses and Applications of Fuses
- Different types of Electrical and Electronic Fuses can be used in all types of electrical and electronic systems and applicationsincluding: 1. Motors & Transformers 2. Air-conditions 3. Home distribution boards 4. General electrical appliances and devices 5. Laptops 6. Cell phones 7. Game systems 8. Printers 9. Digital cameras 10. DVD players 11. Portable Electronics 12. LCD monitor…