The discussion clarifies the differences in ratings between fuses and Miniature Circuit Breakers (MCBs). Fuses are rated at 5, 15, and 30A, while equivalent MCBs are rated at 6, 16, and 32A. The primary reason for this discrepancy is that fuses can tolerate slightly higher short-term currents, blowing at 30A continuous but allowing up to 32A for brief periods. Additionally, Type B MCBs trip at 3-5 times their rated current, which further differentiates their operational characteristics from traditional fuses.
PREREQUISITESElectrical engineers, electricians, and anyone involved in designing or maintaining electrical systems will benefit from this discussion, particularly those focused on circuit protection strategies.
An MCB has two functions: overcurrent heating a bimetallic strip and a solenoid that actuates with very fast rise times, as in a dead short.CWatters said:Not 100% sure but I thinks it's because fuses tollerate slightly higher short term currents. Eg they blow at 30A continuous but tollerate 32A for short periods.
Edit: Think that might be wrong because type B MCB actually trips at 3-5 times the rated current.