Choosing and installing circuit breakers
Circuit breakers are vital components of your home's electrical system. These devices regulate the amount of current flowing through your wires, and are designed to cut off the flow of electricity immediately if there's an overload. This can prevent electrical fires from starting and causing property damage, injury and even loss of life.
How Electrical Circuit Breakers Work
To understand how AC and DC circuit breakers work, you need to have a working knowledge of three electrical principles: voltage, current and resistance. Voltage is, essentially, the pressure-driven force that causes electricity to move through a circuit. Current represents the amount of electricity in a circuit, quantified by the rate at which it is flowing. Resistance is a kind of check created as a byproduct of the presence of voltage and current. The interactivity of these three elements defines how much electrical flow is moving through a circuit at any given time.
Circuit breakers monitor the amount of electrical flow moving through a circuit. If the flow ever exceeds strictly defined limits, your circuit breaker will "trip," which automatically stops the flow of electricity.
Installing Circuit Breakers
Though it may be daunting, given the dangers inherent to working with electricity, installing circuit breakers is actually a fairly straightforward process. Before you begin, make sure that the circuit breaker you're installing has the same rating as the one you're removing. Then, shut down all power flowing into the electrical box where the circuit breaker is mounted.
Next you will disengage the old circuit breaker from the bus bar, and then connect the new ground wires attached to your replacement breaker. Then, place the new circuit breaker in the same position as the old one and drive in screws to keep it in place. When you're finished, turn the power back on and go check each of the electrical outlets controlled by the circuit breaker to make sure they're working properly. These same general steps hold true even if you're installing specialized electrical devices like miniature circuit breakers.
Whenever possible, you should favor new equipment over used circuit breakers. However, if the used circuit breaker was manufactured relatively recently and is in good working order, you can use it to save a few dollars. Just make sure it's safe and approved for use, and if you're ever in doubt, don't hesitate to contact an electrical contractor for help.