An 8 AWG wires can carry 40 to 55 amps of electrical current, depending on the type of wire used. Non-metallic cables can carry 40 A, copper wire can carry 50 to 55 A and aluminum wires can carry 40 to 45 A.
Knowing the ampacity of a particular wire helps to determine which electrical devices can be linked to the circuit without causing the wire to overheat. If using 8 AWG non-metallic wires, for example, make sure that the sum of the amperes of all the electrical devices does not exceed 40 A. To compute the total amperes, add the wattage of the electrical devices and divide the sum by the voltage of the system, 110 or 120 volts.