Many older homes have inadequate electrical wiring for modern use, including too few outlets and an incorrect number of circuits and breakers. They may also have small-capacity circuit breakers that aren't appropriate for some appliances. Before plugging in a new refrigerator or other appliance, check the breaker size to ensure compatibility. When adding new circuits, consider what you'll plug into that circuit when you install the breaker.
Single-pole circuit breakers protect a single wire, supplying 120 volts to the circuit. Most single-pole breakers are 10 to 20 amps, and they are the most common breakers in homes, according to The Home Depot. These breakers come in full size, half size and twin. Twin breakers control two circuits. Use a 15-amp to 20-amp breaker for gas ranges, dishwashers and washing machines. Microwaves and most refrigerators need 20 amps, while gas dryers require 15.
Double-pole circuit breakers use up two slots in your breaker panel. These breakers combine two single-pole breakers but have just one handle. They can supply up to 240 volts to a circuit and can be rated for up to 200 amps. Use a double-pole breaker for big appliances such as electric clothes dryers, which need 30 amps or more. Electric ranges require 40 to 60 amps, and electric water heaters need at least 30 amps.
Ground Fault Circuit Interrupter Breakers
The ground fault circuit interrupter, or GFCI, breaker cuts power when the current overloads, when there's a short circuit, or when there's a line-to-ground fault. You should always install this type of circuit breaker in any room where appliances might get wet, including the laundry room, kitchen, bathroom and garage. Avoid using a GFCI breaker for appliances that have to run all the time, such as refrigerators or electric furnaces, since the breaker could trip without you becoming aware of it.
Arc Fault Circuit Interrupter Breakers
Arc fault circuit interrupter, or AFCI, breakers, protect against fire from unexpected electrical discharge. Use AFCI breakers in 15-amp to 20-amp circuits that include light fixtures or receptacles, but not where a GFCI breaker would be appropriate or where the appliance is wired directly in. You can also use a standard double-pole or single-pole breaker for outlets in unfinished basements or other areas of low fire risk.