1) It is the cheapest form of protection. 2) It doesn’t need any maintenance . 3) Its operation is completely automatic and requires less time as compared to circuit breakers. 4) The smaller sizes of fuse element impose a current limiting effect under short-circuit conditions.
Q. How many times can a MCB trip?
The MCBs with this class characteristics experience instantaneous trips whenever the currents flowing through them is reaching between 2 to 3 times its rated current. These MCBs are usually very sensitive to short circuit and can be used for protecting highly sensitive devices such as semiconductor devices.
Q. What is the principle of MCB?
The working principle of MCB Whenever continuous overcurrent flows through MCB, the bimetallic strip is heated and deflects by bending. This deflection of bi-metallic strip releases a mechanical latch.
Q. What is the limitation of fuse?
Disadvantage: During short circuit or overload once fuse blows off replacing of fuse takes time. During this period the circuit lost power. When fuses are connected in series it is difficult to discriminate the fuse unless the fuse has significant size difference.
Q. What is the most important characteristics of a fuse wire?
Characteristic properties of a fuse wire: (i) It is made up of an alloy of lead and tin. (ii) It has high resistivity and low melting point.
Q. Which fuse is better for accuracy?
Use 400Vdc or higher rated fuses on the secondary side of the transformer or on battery powered applications (ac or dc, typically lower voltages, but not always).
Q. Which fuse is very fast in operation?
Semiconductor fuse
Q. Which wire is used in hospital?
Separate ground wire is used in hospital wiring systems. Local codes for home wiring do not require this separate grounding when metal conduit may serve as the ground return path.
Q. What is cut off current in fuse?
A fuse cuts off current when the current exceeds a safe value due to short circuiting or overloading. When the current becomes large it heats the fuse wire too much. Since the melting point of fuse wire is low it melts and breaks the circuit. Thus current in the circuit is cut off. Related Answer.
Q. What is the various types of fuse?
Fuses can be divided into two major categories, AC fuses, and DC fuses. The below block diagram illustrates the different types of the fuse under each category.
Q. What is the difference between Fuse and MCB?
Fuse is an electrical device that self-destructs and stops the current flow in a circuit whenever the current exceeds the predefined value. MCBs are resettable circuit protection device that, on the occurrence of faults, stops the current flow in a circuit.
Q. Which metal is used in MCB?
Construction of MCB The metal or current carrying parts are made up of electrolytic copper or silver alloy depending on the rating of the circuit breaker. As the contacts are separated in the event of an overload or short circuit situation, an electric arc is formed.
