Most of us have heard the terms “MCB” and “MCCB” at some point of time. But as a layman, we could hardly differentiate between them. Even though both MCB and MCCB are circuit breakers, there are some specific differences which make them apt for particular use. First of all, let’s understand what the abbreviations MCB and MCCB stand for. The MCB stands for “Miniature Circuit Breaker”, while the MCCB for “Molded Case Circuit Breaker.” Before moving on to know the key differences, get acquainted with the fundamentals of MCB and MCCB.
What is a Miniature Circuit Breaker (MCB)?
An MCB, or a miniature circuit breaker, is an automated electrical device intended to protect an electrical circuit from damage caused by excess current, usually occurring from an overload or short circuit. However, fuse may sense these conditions but it has to be replaced though MCB can be reset. Its fundamental function is to interrupt the current flow once a fault is detected. Its working principle is quite simple. The MCB has two contacts, where one is movable and the other one is fixed. As the current increases from the predefined limit, the movable contacts get disconnected from the fixed contacts, consequently, the circuit gets open and disconnect them from the main supply. When it comes to house applications, MCB is the most preferred choice for overload and short circuit protection.
What is a Molded Case Circuit Breaker (MCCB)?
MCCB stands for Molded Case Circuit Breaker. It is another type of electrical protection device which is used when load current exceeds the limit of a miniature circuit breaker. The MCCB provides protection against overload, short circuit faults and is also used for switching the circuits. It can be used for higher current rating and fault level even in domestic applications. The wide current ratings and high breaking capacity in MCCB find their use in industrial applications. MCCB can be used for protection of capacitor bank, generator protection and main electric feeder distribution. It offers adequate protection whenever an application requires discrimination, adjustable overload setting or earth fault protection.
Difference between MCB and MCCB.
MCB | MCCB |
It stands for Miniature Circuit Breaker | It stands for Molded Case Circuit Breaker |
Rated current not more than 125 Ampere | Rated Current up to 1600A |
Its interrupting current rating is under 10KA | Their interrupting current ranges from around 10KA -85KA |
Judging from their power capacities, MCB is mainly used for low Breaking capacity requirement mainly domestic | MCCB is mainly used for both low and high Breaking capacity requirements both domestic and industrial |
Its trip characteristics are normally not adjustable since they basically cater to low circuits | Its trip current may be fixed as well as adjustable for overload and magnetic setting |
Concluding Remarks:
Circuit breakers are installed in the buildings to ensure the safety of your electrical equipment. They make sure to evade fire hazards or other electrical issues by disconnecting the flow of current, the moment they experience a short circuit or an overload. That’s why; both MCB and MCCB should be installed by professionals to minimize the possibility of error. Simultaneously, it’s important to choose the right MCB or MCCB to ensure safety of your loved ones.