Circuit Breaker Lifespan The average lifespan for a circuit breaker is 30 to 40 years. However, this number can go up or down based on various factors.

The primary difference between the two is that an MCCB has a higher interrupting capacity, meaning it can handle larger loads than a conventional breaker. Generally, a standard breaker is used for residential and light commercial applications, while an MCCB is suitable for industrial and heavy commercial applications.

From the appearance, the size of moulded case circuit breaker is different from that of and air circuit breaker. The size and volume of ACB are larger, while that of MCCB is relatively small. Moreover, the current level and breaking capacity of air circuit breaker are greater than those of molded case circuit breaker.

The rated breaking capacity (Icu) or (Icn) is the maximum fault-current a circuit-breaker can successfully interrupt without being damaged. The probability of such a current occurring is extremely low, and in normal circumstances the fault-currents are considerably less than the rated breaking capacity (Icu) of the CB.