Hello, readers welcome to new post. Here we will discuss about What is Fuse. Fuse is a very commonly employed protective instrument in the electrical system. In commonly used in systems operating at low voltage levels. It is also used for a circuit that uses medium-level volts and for distribution lines of eleven kilovolts that use switch and contactors having fewer short circuit features.
Currently, there are different types of fuses are constructed having certain values for current and volt ratings, response time, and breaking capacity. Here we will cover the different features of fuse and applications. So let get started.
Rewireable Fuse
- This type of fuse when operating then can be replaced with a new wire after. WIre of fuse is placed in the asbestos tube to stop the splashing caused by the volatile metals.
- Its drawback is that offered incorrect protection due to the inaccurate ratings
- due to open environment arrangements, deterioration of components occurs.
Cartridge Fuse
- In this fuse silver component having a certain shape positioned in a barrel of insulating material has quartz
- The combination of insulators and quarts gives protection from the arc
- Fine rating values and features of fuse always give the circuit not used for the rewireable fuse.
- Arc and energy existing in the insulating tube due to fault stop damage.
- Its stability is largely due to sealed pack and less face environmental conditions
- It is normally used for high short circuit duty due to high-speed operation and can handle one lac ampers current
Fuse Operating characteristics
- The inverse characteristic of a fuse can be seen here. Inverse means that can bear the nominal current values indefinitely and with the current increment their withstanding time decrease caused to blow them
- The blowing time reduces with the current increment
Fuse British standard 88
- These standards restrict the increment in temperatures
- The fusing factor is 1.4
- Also, restrict the breaking capacity
- These parameters depend on one another and to make them balance good quality fuse can be configured.
- If the fusing factor is smaller temperatures is large so close protection and the possibility of blowing are needed
Energy let through of Fuse
- The operating speed of the fuse is high and remove the fault current before it get the first peak
- If fuses remove the power in the first quarter of the cycle in result power will be I²t
- By making a comparison circuit breakers can remove faults up to ten cycles and let-through power will summation of I2 in case of ten cycles
- The energy released at the fault is so close compared to the energy of the fuse.
Selection of Fuse on bases of Applications
- If current passing in the fuse remains til their baring time this blow
- These features restrict the usage of fuses in circuitry that has an inrush current high.
- Since motors draw the inrush current six times larger than the full load current so fuse cannot be used in overload protection
- So fuse preferred for short circuit current then overload.
- Fuse used for short circuit protection and overload protection based on some parameters discussed below.
- For circuits where loads do not change over the normal value when switching is on and operating conditions
- Resistive circuits have these features so for these loads fuse can be used to get overload protection
- Can also be used for short circuits
- Such circuits that have variation in the loads over the normal ratings such as direct online motors crans rolling mills
How does a fuse work?
- The main working of use is to disconnect the circuit as a result of high current flow as compared to the required value of the circuit to avoid any circuit damage.
- The simple design of the fuse comes with a resistive component that is used based on the melting point. The working of use is that if current flows through this resistive component, voltage losses occur over the component, and power is dissipated in the form of heat.
- The temperature of the component increases if the current is in a safe range and high temperature does not cause the filament to melt. But if the current increases, then the rated value of uses in the resulting melting point is reached.
Characteristics of Fuses.
Current Rating
- The fuse current rating defines its high current-carrying capacity without damage. So use a fuse with a high rating as compared to the circuit operating current for providing protection.
Voltage Rating
- Voltage rating defines high voltage fuse can interrupt in a safe way. The use of a fuse with a voltage rating is good to provide effective protection.
Breaking Capacity
- Breaking capacity defines that feature for breaking the circuit if the current has a high value. High breaking capacity is good for protection from electrical faults.
Operating Characteristics
- Operating features define how the fuse operates for different current values. Time delay fuses such as tolerate brief current surges and fast-working fuses blow fastly at the time of overcurrent events.
Size and Shape
- There are different types of fuses and sizes based on uses. So select according to your circuit demand.
Temperature Sensitivity
- Fuse has a sensitive nature to temperature, which affects their working. Use a good fuse with a good working temperature for applications.
Resettable vs. Non-Resettable
- PTC fuse has resetting features and is reused after cooling. A non-resettable fuse needed to be replaced when blown out.
Materials
- There are different materials used for fuses, such as copper, zinc, and aluminum for conductive components.
How to Choose the Proper Rating of Fuse?
- Check normal working current conditions in the device manual.
- Check for current and temporary power surges if the device starts. Motors and transformers needed time delay fuses for controlling surges.
- For using an accurate fuse rating, take a multiple of the normal operating current with a safety factor that is between 1.25 and 1.5 times.
- Make sure that the fuse voltage rating is according to the voltage circuit. The voltage rating is equal to or higher compared to the maximum voltage.
- Use a fuse that has a breaking capacity that interrupts high current in the circuit.
- Note the size and shape of the fuse that is supported with the fuse holder. Since fuses are in different shapes and sizes.
- Check that fuse handle temperature of different ranges. It is important to use a fuse that provides reliable features for working conditions in extreme temperatures.
Advantages of Electric Fuse:
- The main feature of fuses is that they provide safety for circuits and protect devices from getting damaged from overload current.
- It also does detection and interruption in case of faulty conditions.
- There are many types of uses that are low-cost.
- It is a smaller size and easier to carry than switchgear protection equipment.
- If operation is not needed, maintenance.
- It breaks automatically in case of fault without causing noise and gas.
- It needed less time to break the circuit in a fault condition.
Disadvantages of Electric Fuse:
- The main drawback is that it needs to be replaced with a new fuse if it operates in case of a fault. We can also rewire the fuse.
- Fuse is not recommended for high voltage rating circuits.
- It is not used many times after fault conditions.
Read also
- How to test a fuse with a multimeter
- Difference Between Fuse and Circuit Breaker
- Difference Between Thermal Fuse and Thermal Switch
- Introduction to GFCI and AFCI Circuit Breakers
