Difference Between Fuse and Circuit Breaker

The fuse and circuit breaker are circuit protection devices used to protect the system from over-current conditions in power system industries. Both do the same but differs from their various characteristics and working principle. Let’s see the difference between the fuse and circuit breaker.

Difference Between Fuse and Circuit Breaker

But, before that, we will explore why we need fuse and circuit breakers?

Need for Circuit Breaker and Fuse

In most of the electrical and electronics applications, it is quite common that electrical system experience over current. This may overheat the components present inside the system and affect the system reliability and in some cases, it may totally damage the system along with the persons nearby.

Disadvantages of Over Current

  • Overheats system components
  • Damages equipment
  • Damage insulation
  • Bends and twists bus cables.
  • Cracks will occur for cables and insulators, and Spacers
  • Fire explosions and hazardous fumes exist due to over current.

Moreover, an increase in loads (lights, motors, machines) results in overload and short circuit problems. To overcome this, overload protection devices such as fuse and circuit breakers are used.

Comparison

FuseCircuit Breaker
Fuse works on the principle of electrical and thermal properties of the conducting materialsCircuit breaker works on the principle of electromagnetism and switching
It operates automaticallyIt operates manually and automatically
It needs to be replaced after every operationNo replacement is required
It can be used only once. It is a one-time protection deviceIt can be reused
No auxiliary contact is requiredThey are available with auxiliary contact
It cannot be used as ON/OFF switchIt is used as ON/OFF switch
It can break the circuitIt can make or break the circuit
They are independent of ambient temperatureIt depends on ambient temperature
Fuse is smallIt is larger in size
It provides protection against only power overloadsIt provides protection against power overloads and short circuits
Fuse can detect and interrupt the fault currentIt performs only interruption. Faults are detected by the relay system
Breaking capacity of the fuse is lowBreaking capacity is high for circuit breakers
Operating time is very less (0.002 secs)Operating time is more than fuse (0.02 – 0.05 secs)
Cost is lowCost is high

Conclusion

Based on the difference between fuse and circuit breaker, a fuse is used in electricity meters for houses and in electronic circuits for overcurrent protection. A circuit breaker is reliable as well as reusable as it controls high currents.  But, if you want to switch circuits with small currents relays are preferable.

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