Difference between Fuse and Circuit Breaker

This article discusses the key differences between Fuse and Circuit breaker on the basis of practical factors such as their Functionality, Operation Time & Mode, Breaking Capacity, Representation, Temperature Effects, and Applications.

A fuse and circuit breaker both of them protect an overloaded circuit by disrupting the current continuity. The way they disrupt the current flow is dissimilar. A fuse is a simple piece of metal that melts down when overheated because of excessive flow of current whereas a circuit breaker has switching mechanism that is activated when unsafe current flows through the circuit. Fuses are faster to disrupt the current flow but they must be replaced after a piece of metal melts down, whereas circuit breakers can be reset and used multiple times.

The most significant distinguishing factor between fuse and circuit breaker lies in their operational mechanism. The fuse functions at the base of thermal as well as electrical characteristics of the conducting metal which is utilized in the fuse, whilst a circuit breaker functions on the base of electro-mechanical principles.

The following table covers the key Differences between Fuse and Circuit Breaker.

Difference between Fuse and Circuit Breaker

CharacteristicsFuseCircuit Breaker
FunctionPerforms detection as well as interruption function.Performs interruption function ONLY.
Operation ModeInherently completely automatic operationNeeds comprehensive equipment such as relays for automatic operation
Operating timeVery small like 0.002 sec or even lessComparatively large (ranges between 0.1 and 0.2 seconds)
ReplacementHave to replace after every operationNo need to replace after every operation
Operation principleIt’s operation is based on the heating property of a conducting material It’s operation is based on switching mechanism (which is electromechanical in nature)
Breaking CapacitySmallLarge
RepresentationFuseCircuit Breaker
TemperatureCompletely independent of an ambient temperature Depends on an ambient temperature
Characteristics curveBecause of ageing, characteristic curve shifts Does not shift.
CostLow costVery high mainly depends upon application
ProtectionProvides protection against overloadProvides protection against overload as well as short-circuit in the system
Post-OperationIt is replaced manually after operationIt can be reset quickly after operation
Application Used extensively in an electronic equipment’s which draw low currentUsed in power equipment's such as in motors and other heavy machines which draw a large amount of current