220v 20 Amp Wire Size. Southwire 19178806 83 Heavy-Duty STW 40-Amp250-Volt Nema 6-50 Blue Welder Extension Cord 25- Feet 8-Gauge STW jacket for Superior Performance Rated at 40 Amps 250 Volts and 10000 Watts 49 out of 5 stars 863. So if your running a 20amp circuit at 220v a distance of only 20ft you would want to run this with 12ga wire.
Staple the cable to the wall framing then turn the power back on. The lower the number the thicker the wire. Amperes - Enter the maximum current in amps that will flow through the circuit.
Voltage - Enter the voltage at the source of the circuit.
Amperes - Enter the maximum current in amps that will flow through the circuit. Snap a new two-pole 20-amp 220-volt circuit breaker into the panel. Replace the cover on the sub-panel. The wire size chart below shows allowable ampacities of insulated conductors rated up to and including 2000 Volts 60C through 90C 140F through 194F not more than three current-carrying conductors in raceway cable or earth directly buried based on ambient air temperature of 30C 86F.
