Two responses Yes, 10 AWG copper wires may be used with a 20-amp breaker. Copper conductors of 12 AWG are the lowest size that may be utilized with a 20-amp breaker. The reason for this limitation is that these smaller wires will heat up when current is flowing through them, which could cause a fire.
The wiring in a house is designed to handle normal household current levels of 120 volts and less than 15 amperes. However, many appliances that are plugged into a wall outlet use power tools or other equipment that can overload regular wiring. These devices should be set up using special overload circuits to prevent damage to the equipment and possible fire hazards if not done properly.
If you are unsure about how to configure your home's electrical system, contact an electrician before you install any new appliances or make any major changes to your existing wiring.
Use # 14 copper wire (or # 12 copper-clad aluminum wire) for a 15-amp circuit. This circuit's fuse or circuit breaker is rated for 15 amps. Use # 12 copper wire (or # 10 copper-clad aluminum wire) for a 20-amp circuit. This circuit's fuse or circuit breaker is rated for 20 amps.
#10 copper wire weighs 3 ounces per 100 feet. #12 copper-clad aluminum wire weighs 2½ ounces per 100 feet. So, if you need more wire than what's listed here, use the heavier weight.
The American Wire Gauge defines the maximum cross-sectional area that can be occupied by one insulated conductor within a given gauge metal. The term "ampere-hour capacity" means the total amount of current that can be carried by a circuit under specified conditions.
For example, if you specify #14 copper wire and a #20 amp service, it means that the circuit will carry a maximum of 20 amperes of load current at 5 volts potential difference between two points on the circuit. If the load requires more current than this, then another type of wiring needs to be used instead.
It's important to choose the correct size of copper wire for your circuit based on how much current it will have to carry. Too often, people will use too small of wire for their project, which can lead to poor connection quality and increased risk of fire.
As a general rule, 12-gauge wire may securely support 10 receptacles on a 20-amp copper wire circuit. 14-gauge wire, on the other hand, can accommodate 15 amps and 8 receptacles. A wiring diagram will help determine exactly how many outlets you can install on a circuit.
The United States electrical code requires that all household circuits be equipped with at least one outlet to which a plug can be connected. If you plan to have more than one appliance plugged into a single circuit, you will need to replace that circuit with a 20-amp service. The National Electrical Code also requires that all outlets have ground pins to which they can be connected. This ensures that someone will find any live wires in an outlet by making sure there is some way to connect it to metal piping or another ground source.
An electrician should check all household circuits to make sure they are able to handle the load they are being asked to serve. He or she will do this by measuring the resistance of each conductor with a voltmeter. If one conductor has more resistance than the others, the extra load will cause your circuit to fail safety tests set forth by law. The electrician will also look to see if any conductors are damaged or frayed; if so, they should be replaced.