Difference between Isolator, RCCB, & MCB

Difference between Isolator, RCCB, & MCB

Isolators, RCCBs, and MCBs are very frequently used when working with electrical circuits and appliances. While they have very similar purposes, they do have subtle differences that distinguish one from the other. As someone who deals with electrical components regularly, it is important to know these differences. So, here are the main differences between the MCB, the RCCB, and the Isolator. 

Differences Between Circuit Breakers and Isolators

  • RCCB (Residual Current Circuit Breaker) and MCB (Miniature Circuit Breaker) are forms of circuit breakers that are used to disconnect the flow of electricity through a circuit whenever an electrical surge is detected. Isolators, on the other hand, are used to isolate a circuit or an appliance from the source of power.
  • Circuit breakers are precautionary or safety devices installed across electrical circuits that keep appliances secure from sudden electrical surges and prevent accidents like electrical fires and electrocution. Isolators are used to deliberately cut the circuit off from the power source for repair and maintenance. 
  • To allow a steady flow of current to not interfere with the appliance's working, circuit breakers have a higher breaking capacity. This does not trigger when the flow of electricity is normal. As isolators are meant for cutting off the flow of electricity throughout the maintenance, they have really low breaking capacities which are triggered by the slightest amounts of electricity flowing through the circuit. 
  • Circuit breakers can operate during offloads and on-loads. Isolators, however, can only function during offloads. 
  • Circuit breakers can operate automatically to disconnect the electrical circuit during unprecedented electrical surges, but they can also be operated manually. Isolators, however, can only be operated manually. 


Differences Between MCBs and RCCBs

While both RCCBs and MCBs are used for the same purpose, they have several differences between them. Some of the major differences are as follows:

  • MCBs are effectively used to prevent any damage to the circuit or the electrical appliance during a sudden electrical surge. An RCCB circuit breaker, on the other hand, is meant primarily for the safety of human beings. Residual current in a circuit can be lethal, and RCCBs are commonly helpful against accidental electrocution. 
  • MCBs can be used in residential, commercial as well as in industrial settings. On the contrary, RCCBs are used chiefly in residential settings for preventing electrical accidents. 
  • The working principles for the two are different. MCBs operate on the principles of thermal overload protection and are equipped with components that are sensitive to temperature. Whereas, RCCBs work on the principle of core balanced current transformer, which means it will respond to earth faults automatically thus preventing electrocution. 
  • As opposed to the lower sensitivity in MCBs RCCBs are highly sensitive. This helps prevent any accidental electrocutions. 
  • MCBs are available in ranges of single-pole, two poles, three poles, and four poles. RCCBs can have two, three, and four poles. They are not available as single-pole variants. 


The above are the notable differences between isolators and circuit breakers, as well as RCCBs and MCBs. For attractive offers on Isolators, MCBs, RCCBs, or any other electrical components, you can visit the Schneider Electric online store. Schneider Electric provides all your electrical wants and requirements in one convenient place. 


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