I. General Considerations
In certain situations, an Electrical Engineer may encounter a project requiring a miniature circuit breaker (MCB) to be equipped with a 50BF device for breaker failure protection. Although this practice is uncommon, it may be specified as a project requirement.
To integrate a 50BF device with an MCB, it is essential to properly incorporate it into the protection system. The primary function of the 50BF device is to detect the MCB's failure to interrupt fault current and to trigger backup protection mechanisms.