4 Reasons Why Circuit Breakers Trip and Fuses Blow But in order to avoid having it happen again, it is also important that you understand why the breaker has tripped or the fuse has blown. In rare cases, the breaker may be damaged and v. But in most cases, the breaker or fuse is just doing its job when it pops. Circuit breakers are designed to trip and fuses are designed to blow and turn offAuthor: Bob FormisanoGround-Fault · Overloaded Circuit · Short Circuit · Using a Circuit Breaker Finder BrightNest | Fix a Blown Fuse or Reset a Circuit Breaker For a fuse box: If your electrical panel has fuses, check each fuse to see if the piece of metal inside has melted, or if the glass window at the top of the fuse has become discolored (usually purple or brown). That’s your broken fuse. Unscrew the broken fuse and replace it with a new fuse that is the exact same size, type and amperage of the broken fuse.