Fuse is a important circuit interrupting device to cut-off load and protect it from over loading and short circuit current. When over load occurs circuit carry more than rated current. As long as this rated current flow in the circuit, conductors temperature increases, it will damage conductor and creates new permeant faults. To avoid such circumstances, the fuse element must be melt in its rated current. Further it is not also not affected from external factors to change is properties.
Important characteristics of Fuse elements
A fuse element to work efficiently , it should have following desired qualities
- Low Melting Point
- High Conductivity
- Free from number deterioration due to oxidation
- Less cost
1. Low Melting Point:
A fuse element should have a low melting point so that it can melt quickly and interrupt the circuit when excessive current flows. This helps protect electrical devices from damage caused by overheating or short circuits.
2. High Conductivity
High electrical conductivity is important to allow normal current to pass through the fuse with minimal resistance. This reduces power loss and prevents unnecessary heating of the fuse during regular operation.
3. Free from Deterioration Due to Oxidation
The material used in the fuse should resist oxidation to maintain consistent performance over time. Oxidation can increase resistance or weaken the fuse element, leading to unreliable operation
4. Less Cost:
The fuse element material should be low in cost to make the fuse economical, especially for widespread and disposable use. Using affordable materials ensures practicality in large-scale manufacturing and consumer applications
Characteristics of Fuse Element
The following graph illustrates the important characteristics of fuse elements, showing the relationship between time and current-carrying capacity. In the graph, current is represented on the Y-axis with a linear scale, while time is plotted on the X-axis using a logarithmic scale. This graph represents the connection between pre-arcing time and prospective current. It shows that as the prospective current increases, the pre-arcing time decreases. In other words, the fault current and operating time are inversely related. The curve also becomes asymptotic, indicating the presence of a minimum current below which the fuse will not operate. This is known as the minimum fusing current. Near this current level, the operating time of the fuse is significantly longer.
