Difference Between MCB and MCCB: Definition & Applications

Ans. The major differences between MCB and MCCB are as follows:

Ques. What is MCB? (3 Marks)

Ans. MCB stands for Miniature Circuit Breakers. It is an electromechanical device which switches off the circuit automatically if an abnormality is detected such as overload and short circuit conditions. It is a low voltage circuit breaker used for low energy requirements such as small electronic circuits or home wiring. It is the most preferred choice for overload and short circuit protection. 

Ans. MCCB is an abbreviation used for Moulded Case Circuit Breaker. It is an electrical protective device used to protect the circuit from overloading. It offers protection against overload, short circuit faults and is also used for switching the circuits. MCCB is used in high energy requirement regions such as high-power equipment in industries or for commercial purposes.

Ans. Some similarities between MCB and MCCB are as follows: 

• MCB and MCCB both offer protection to an electric circuit.
• Both of them sense and protect the power circuit from the short circuit or overcurrent situation.
• Both of them can be used in low tension or low voltage circuits.

Ans. Circuit Breakers are the electrical safety devices of any property. They act as a third party within a dangerous electrical wiring system. Some of the circuit breakers are MCB, MCCB, RCD, RCCD, and RCBO. They are used in homes as well as industrial settings to provide protection against appliance damage and related hazards. All these circuit breakers are designed to perform specific functions. 

Ans. An electrical fuse is a safety device which offers protection against the overflow of current in an electrical circuit.

The important uses of electric fuse are as follows: 

• It prevents device failure caused due to faulty circuit operation.
• It prevents overload, blackout and short-circuits.
• It helps to prevent damage caused due to mismatched loads.

Ans. A short circuit occurs when the current in the circuit increases heavily and the electrical connection draws excessive current from the supply. The magnitude of the current in a short circuit is very high at this point. Short circuit occurs when neutral and live wires touch each other.

Ans. MCCB features two arrangements, one for the overcurrent and other one for the over-temperature. MCCB has a bimetallic contact that contracts and expands when the temperature of MCCB changes.

The bimetallic contact enables the current to flow through the circuit during normal operating conditions. In those cases where the current increases beyond the preset value, their contacts warm and expand until the contacts are open. As a result, the circuit disconnects from the main supply and protects the equipment from damage.

Ans. RCCB is an abbreviation for Residual Current Circuit Breaker. It is an electrical device that disconnects the circuit whenever there is leakage of current flow through the human body or the current is not balanced between the phase conductor. RCCB is the safest device to detect and trip against electrical leakage currents. Thus, it ensures protection against electric shock caused by direct contact.

Ans. ELCB is an abbreviation used for Earth Leakage Circuit Breaker. ELCB performs the same function as RCCB but it is a voltage sensor device. This means it is outdated technology and is not utilized commonly now. It only detects the current that flows back through the main earth wire.

Ans. MCB guards the electric wires and electrical load from overcurrent in order to avoid any kind of fire or electrical hazards. It is quite safe to handle MCB and it quickly restores the supply. Thus, MCB is the most preferred choice for overload and short circuit protection when it comes to house applications. It also doesn’t have any maintenance costs.