20 Amp Wire Size Chart. One rule of thumb is to assign a maximum draw of 15 amps to each receptacle which allows for 10 receptacles on a 20-amp circuit. A lower rating will decrease the current-carrying capacity of the wire.
All wiring in such circuits must be 12-gauge or larger. The National Electrical Code NEC recommends a maximum voltage drop of 3 percent for individual household circuits known as branch circuitsThis is a good goal to shoot for when sizing the conductors for an underground cableThe following are the maximum lengths of cable you can use while still maintaining a 3 percent voltage drop for the given wire size AWG and. For a 40 amp you need a 8-gauge wire size and for a 20 amp you will need a 12-gauge.
Choosing the correct wire A Locate the CURRENT IN AMPS of your appliance across the top of.
Choosing the correct wire A Locate the CURRENT IN AMPS of your appliance across the top of. One rule of thumb is to assign a maximum draw of 15 amps to each receptacle which allows for 10 receptacles on a 20-amp circuit. A lower rating will decrease the current-carrying capacity of the wire. For motors it is recommended to multiply the nameplate FLA by 125 for wire sizing.
