The NEC (National Electrical Code) defines a circuit breaker as “a device designed to open and close a circuit by non-automatic means, and to open the circuit automatically on a predetermined overcurrent without damage to itself when properly applied within its rating.”
Although circuit breakers have been around since the 1830’s, it wasn’t until the 1950’s that they began to replace fuses for residential use as the norm. Prior to 1950 homes had fuse panels. These were 30 amp panels that consisted of two fuses that screwed into a ceramic fuse holder, and were mounted in a black metal housing unit. 30 amp service panels supplied 120 volts to a residence. Once a fuse was blown, it had to be replaced. With the advent of electric appliances in the home, the 30 amp service panel was no longer sufficient. As people began buying more and more electric appliances, they began to experience blown fuses on an almost daily basis. They found themselves juggling what appliances could be used at the same time, and that some of the more powerful ones would blow a fuse no matter what if used for a prolonged period of time Commercial Electrical Services.
In about 1950’s the new and improved 60 amp service panel arrived, using circuit breakers instead of fuses. Throughout the 1950’s circuit breaker panels began being installed in new homes, and by 1965 it was the norm in residential use. The 60 amp service panels supplied a whopping 240 volts of power to a home, which is still the standard today. Even today, with the doubling of amperage and volts, we still experience “blowing” a circuit from time to time (many older folks will still refer to it a blowing a fuse), but unlike the old fuses, the breaker just has to be reset. As we find ourselves with more and more electric appliances, and they are also more and more powerful, many homes today have more than one breaker panel, and each circuit breaker covers a smaller number of outlets, or power sources.
Most older homes have been refitted with circuit breaker panels, though you can still come across one with the old 30 amp fuse panel from time to time. Many homes built in the 50’s and 60’s are in need of having their breaker panels replaced with larger more efficient panels in order to support the number of electric appliances found in the modern home today. Stores that specialize in power breakers can recommend the right replacement panel. Always refer to a specialist before making a decision about the size and type of a replacement panel.