AWG # 14 is the smallest wire you can install in a home and it can only be used in living areas. It will carry 15 amps.
A #8 copper wire with an insulation factor of 75 or 90 degrees C is rated at 45 amps.
A #6 copper conductor with an insulation factor of 75 and 90 degrees C is rated at 65 and 75 amps respectively.
The minimum wire size allowable would be 10 gauge. For a 75 foot run however, the voltage drop would be 5.31 volts. This exceeds the NEC recommendation of no more than 3% (3.6v) so while it is not legally required, for best efficiency, you should run 8 gauge.
Aluminum 4/0 wire car carry 180 amps at at 75 degrees Fahrenheit or 205 amps at 90 degrees. .
A #12 aluminium conductor with an insulation factor of 75 or 90 degrees C is rated at 15 amp. Therefore the largest size breaker to protect that wire will be a breaker rated at 15 amps.
A #6 copper wire with an insulation factor of 75 and 90 degrees C is rated at 65 amps.
A 1/0 copper wire with an insulation factor of 75 or 90 degrees C is rated at 150 and 155 amps respectively.
#8 copper
A #12 copper wire with an insulation rating of 60, 75 or 90 degrees C is rated at 20 amps.
A #8 wire with an insulation rating of 75 or 90 degrees C is rated at 45 amps.
A #8 copper wire with an insulation rated at 75 or 90 degrees C is rated at 45 amps.
55 <<>> A #6 copper conductor with an insulation factor of 75 or 90 degrees C are both rated for 65 amps.
A #8 copper wire with an insulation factor of 75 or 90 degrees C has an ampacity of 45 amps. A #8 wire with an insulation factor of 60 degrees C has an ampacity of 40 amps.
10 AWG in copper.
Maximum amps for chassis wiring : 101 amps Maximum amps for power transmission : 37 amps Reference : http://www.powerstream.com/Wire_Size.htm
I am assuming that this is a one and a half HP motor. To wire a 120V 20A motor the electrical code states that the conductor has to be 125% of the motor's full load amps. This equals 25 amps. There is no wire rated at 25 amps so the next size up is 30 amps. A #10 copper wire with an insulation factor of 60, 75 and 90 degrees C is rated at 30 amps. To carry this to a conclusion This #10 wire should be protected by either 60 amp non time delay fuses or 35 amp time delay fuses or a two pole 50 amp breaker.
This is a voltage drop question. To answer this question a voltage must be stated.