Determining the correct circuit breaker size for appliances depends on the size and type of appliance. In some cases, the type of circuit breaker relates to the size.
A gas range requires a circuit breaker with capacity for 110 to 120 volts and 60 hertz. The branch circuit should be properly grounded and polarized and protected by a 15/20 amp circuit breaker or fuse. The house wire should be 14-gauge.
Microwaves, dishwashers, refrigerators and gas dryers also require a circuit breaker with capacity for 110 to 120 volts and 60 hertz properly grounded and polarized. For microwaves, one should use a 15/20 amp circuit breaker or fuse along with 14-gauge house wire. The requirements for a dishwasher are the same except the 15-amp breaker is only suitable if the dishwasher does not include a temperature boost option. If it does, then a 20-amp circuit breaker is necessary, coupled with 12-gauge house wire. The 12-gauge house wire is also recommended for a refrigerator or gas dryer.
Electric dryers and ranges have greater requirements. Both require a circuit breaker with capacity for 220 to 240 volt, 60 hertz, properly grounded and polarized. For the dryer, a 3-amp breaker coupled with 10-gauge wire is required. An electric range requires a 40- or 50-amp breaker coupled with 8-gauge or 6-gauge wire.