Though both are classified under low voltage circuit breakers as per the standards set by IEC 947, an MCCB has much more capacity than an MCB. If evaluated from their power capacities, the MCB is essentially used for low-current requirements, such as, home wiring or small electronic circuits while the MCCB is better used for high-power requirements. It is generally meant for high current circuits. Contrastingly, an MCCB that could be rated from 10 and 2,500 amps (with an interrupting rating from 10,000 amps to 200,000 amps) comes with an adjustable trip feature. So, MCBs generally cater to low current circuits. The MCB rated under 100 amps (with an interrupting rating of under 18,000 amps) doesn’t have an adjustable trip feature. The major difference between MCB and MCCB is their capacity. As a result, the circuit gets disconnected from the main supply, protecting the equipment from damage. However, if the current rises beyond the predefined limit, the contacts will get warm and expand until they get open. During the normal operating conditions, the contact allows the current to flow through the circuit. It has a bimetallic contact, which expands and contracts with the change in temperature. Talking about its working principle, the MCCB has two arrangements one for the over temperature and the other one for over current. Essentially used for high current applications, the MCCB features a manually operated switch for tripping the circuit. However, unlike the MCB, it is used in places where adjustable tripping is required. What is a Moulded Case Circuit Breaker (MCCB)?Īn MCCB, or a moulded case circuit breaker, is an electric device designed to protect the circuit from overloading. 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. The MCB has two contacts, where one is movable and the other one is fixed. Its fundamental function is to interrupt the current flow once a fault is detected. What is a Miniature Circuit Breaker (MCB)?Īn 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.
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. First of all, let’s understand what the abbreviations MCB and MCCB stand for. Even though both MCB and MCCB are circuit breakers, there are some specific differences which make them apt for particular use. But as a layman, we could hardly differentiate between them. Most of us have heard the terms “MCB” and “MCCB” at some point of time.