Miniature circuit breakers are typically used in place of fuses in automobiles and other power equipment. Such circuit breakers are generally only slightly larger than fuses and contain a small button that may be pressed to reset them should they be "tripped" or disengaged due to a power spike or surge. Although designed to be reused after the rare occasional power surge, these miniature circuit breakers can fail over a period of time and should be replaced promptly.
Remove the faulty miniature circuit breaker from the breaker box as you would a regular fuse. Use a pair of needle-nosed pliers to gently clamp around the edges of the miniature breaker and then gently pull it outward from its breaker socket.
Take the faulty miniature circuit breaker along with you to your local automotive store or the dealer who provides sales and service on your particular machine in which the circuit breaker is used.
Purchase a new replacement miniature circuit breaker based on the information printed on the faulty one. All circuit breakers have voltage and amperage rating information printed on them. If necessary, use a magnifying glass to read the ratings on the miniature breaker. The new one must be rated for the same voltage and the same amperage.
Install the new miniature breaker into the empty slot from which the faulty one was removed. Look at the prongs on the circuit breaker and then inspect the socket. Make note of how the circuit breaker prongs should line up with the socket. Once the breaker is oriented so it mates properly with the socket, press it fully into place either until it clicks or it cannot be inserted any farther.
Turn on the power tool, equipment or vehicle and operate the accessories for which the breaker supplies power. If the new circuit breaker disengages after replacement, requiring a reset, take your equipment to a service centre to determine where the electrical short is.
Never replace any fuse or circuit breaker with larger voltage or amperage capacity than the original. If the fuse or breaker continues being damaged, it may indicate an electrical short on the equipment that is causing the problem. Using a higher-rated fuse or circuit breaker may then allow wiring to overheat, causing an electrocution or fire hazard.