Difference between fuse and circuit breaker

The difference between the fuse and circuit breaker are explained considering various factor like working principle, reusability, an indication of status, the requirement of the auxiliary, breaking capacity, protection, curves, its function, temperature and mode of operations.

The most significant difference factor between fuse and circuit breaker is that lies in their operational mechanism. The fuse is a base of thermal as well as electrical characteristics of the conducting metal which is utilized in the fuse while in circuit breaker functions on the base of electromechanical principles. Let we have a deep insight into the benefits and disadvantages of fuse and circuit breaker to better understand this topic.

What is a fuse?

Fuse is defined as an overall current protective device with a circuit opening fusible element which open when there is an overcurrent in the circuit.

What is the circuit breaker?

A circuit breaker is a device which controls a circuit automatically manually or by remote control under normal and fault conditions like overcurrent or short circuit etc.

Difference between fuse and circuit breaker :

  • Fuse works on the principle of electrical and thermal properties of the conducting materials whereas the circuit breakers work on the electromagnetism and switching principle.
  • The fuse provides protection against only power overloads whereas a circuit breaker provides protection for both power overload and short circuit.
  • Breaking the capacity of the fuse is low as compared to that of a circuit breaker. 
  • The fuse provides both detection and interruption process. Circuit breaker performs the only interruption, a relay system is attached for detection of any fault in the circuit.
  • No auxiliary contact is required in case of fuse but in circuit breaker, auxiliary contact is required.
  • Operating time of fuse is very less about 0.002 second while operating time of circuit breaker is comparatively more than that of fuse, about 0.02 to 0.05 second.  
  • Fuse cannot be used as an ON/OFF switch while in circuit breaker can be used as an ON/OFF as a switch.
  • Fuse is only single pole version is available while in circuit breaker single and multiple pole version is available.
  • Fuses are independent of ambient temperature but circuit breaker depends on the ambient temperature.
  • The cost of the fuse is low whereas the circuit breaker is more costly.
  • Mode of operation off fuse is completely automatic but circuit breaker can be operated manually it causes nuisance and tripping. The curve of the circuit does not shift.
  • Fuses once used cannot be reused again, the circuit breaker can be reused.
  • Fused used extensively In electronic equipment draw low current while in a circuit breaker are used in power equipment such as in motors and other heavy machines which draw a large amount of current.
  • Fused can be replaced after the operation while a circuit breaker can be reset quickly after the operation.
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